Sesamoiditis is one of the most common diseases of dancers and athletes. The essence of the pathology is that in the sesamoid bones, which are located inside the tendons, for one reason or another, an inflammatory process begins to develop.
Most often, this disease affects the sesamoid bones of the first toe, because when walking, dancing, playing sports, especially running, a person relies on them. Therefore, strong and constant physical activity can lead to injury. Even though these dice are no larger than the size of a pea, they play great value in a person's comfortable walking.
Causes
Sesamoiditis of the first toe most often occurs in young people, especially if they prefer to play sports or dance. Therefore, the main cause of the disease can be considered excessive physical stress on the legs without proper rest and alternation of rest modes and sports or dancing.
However, pathology cannot appear overnight. To do this, a certain amount of time must pass and certain conditions must coincide. And the main one is the thinning of the subcutaneous fat layer on the sole of the foot. As soon as this happens, the disease itself gradually begins to develop due to the fact that the sesamoid bones bear an additional heavy load.
However, inflammation is only one half of the problem. If you continue to neglect your health, a fracture of these bones may occur, which almost never heals, and in order to return the legs to their former ease when walking, surgical intervention is necessary.
Often sesamoiditis coexists with another disease - stop valgus. This is especially true for women. Therefore, if you have this diagnosis, it is necessary to more carefully monitor the health of your legs and try to get rid of this problem so as not to get inflammation of the sesamoid bones.
Symptoms
The main symptom of sesamoiditis is pain. Moreover, at the very beginning it is insignificant and few people pay attention to it. However, over time it intensifies and becomes almost unbearable.
The pain intensifies when wearing high-heeled shoes or tight and uncomfortable shoes. However, it is worth remembering that inflammation of these bones and their fracture have similar symptoms. True, with a fracture, more pronounced swelling occurs, and pain occurs suddenly during dancing or playing sports. Moreover, at this moment a person can even be wearing shoes without heels.
In some cases, patients may notice numbness of the first toe. This is very simple to explain. This phenomenon occurs when a nerve is involved in the pathological process. It begins to become inflamed because it is close to the bone itself.
Diagnostics
Diagnosis of the disease, as a rule, does not have any problems. This is done by examining the first toe and interviewing the patient. Sometimes x-rays or MRIs are performed.
If there is doubt about the diagnosis, a joint puncture is performed. This is necessary in order to distinguish inflammation of the sesamoid bones from pathologies such as arthritis, which have almost the same symptoms.
Conservative treatment
Treatment of sesamoiditis is carried out at home and depends only on what caused the inflammation. If the inflammation appears due to hallux valgus, then wearing an individually selected toe helps correct the abnormal position of the first toe, and such treatment quickly leads to recovery without the use of medications.
If the cause is a sports injury, then the treatment is to apply ice to the site of inflammation or use ultrasound. In this case, the legs need rest and a certain period of time without sports training. Thanks to such simple treatment, the pathology also goes away on its own. But in the future you need to treat your feet more carefully.
If the disease progresses to chronic stage, then a cortisol injection, which is given directly into the inflamed joint, helps a lot. However, such injections can only be performed in a hospital setting.
As for the fracture, it is also clearly visible on an x-ray or MRI, however, in 20% of the entire population of the planet, the sesamoid bone is divided into two halves, so this feature is often considered a fracture. This means that only an experienced specialist should diagnose the disease.
The human foot and ankle are complex and highly specialized biological mechanisms. This mechanism is formed by 28 bones, 33 joints and more than a hundred muscles, tendons and ligaments.
Therefore, we decided to make this short excursion, which will allow our patients to understand a little about the anatomy of the foot and ankle joint
The human foot is designed in such a way that it can easily support the weight of our body, while remaining flexible enough to provide us with the ability to walk, run and dance. This is ensured by the work of many joints, some of which are exceptionally mobile, while others are relatively immobile.
In order to describe to you the features various parts feet, we divided it into 3 sections:
Forefoot
This section is formed by five fingers and their corresponding five tubular bones (metatarsals). Similar to the fingers of the hand, the bones that form the toes are called phalanges. The first finger consists of two phalanges, the rest - of three. The joints between adjacent phalanges are called interphalangeal joints (IPJs), and the joints between the metatarsals and phalanges are called metatarsophalangeal joints (MTP joints).
Midfoot
The midfoot is formed by five bones: the cuboid, navicular and three wedge-shaped bones. These bones are involved in the formation of the arches of the feet. The midfoot is connected to the hind and forefoot by ligaments, muscles and plantar fascia.
Hindfoot
This section is formed by the talus and calcaneus bones. Two long tubular bones, forming the lower leg, the tibia and fibula, articulating with the upper part of the talus, form the ankle joint. The talus, in turn, articulates with the calcaneus through the subtalar joint.
The following radiographs show the major bones that form the foot and ankle:
X-ray of the ankle joint in a direct projection
X-ray of the foot and ankle joint in lateral projection
X-ray of the foot in direct projection
- Tibia
- Fibula
- Calcaneus
- Talus
- Scaphoid
- Medial sphenoid bone
- 1st metatarsal bone
- Proximal phalanx of the 1st finger
- Distal phalanx of the 1st finger
- 2nd finger (formed by proximal, middle and distal phalanges)
- 3rd finger (formed by proximal, middle and distal phalanges)
- 4th finger (formed by proximal, middle and distal phalanges)
- 5th finger (formed by proximal, middle and distal phalanges)
- 5th metatarsal
- 4th metatarsal
- 3rd metatarsal
- 2nd metatarsal
- Intermediate sphenoid bone
- Lateral sphenoid bone
- Cuboid
- Sesamoid bones (medial and lateral)
Distal tibia and fibula
The tibia and fibula are two long tubular bones of the lower leg, the distal ends of which, together with the talus bone of the foot, form the ankle joint. The lower ends of both leg bones expand to form the ankles. The ankles are the most common location of fractures in ankle injuries.
Talus
This is one of the bones that forms the ankle joint. The talus can be called an unusual bone. It is the second largest bone in the foot and, unlike other bones, is almost entirely covered with cartilage. Another feature of it is that not a single muscle is attached to it. Thus, it is as if “suspended” between the other bones surrounding it. The blood supply to the talus differs from most other bones: the vessels penetrate the bone only in its farthest part (retrograde blood supply). This makes the talus vulnerable to the frequent development of problems with the healing of lesions in this location, especially with fractures.
The talus is divided into the following sections:
- Head
- Neck
- External process
- Posterior process
Each of these sections can be damaged by injury.
Calcaneus
The heel bone is one of the two bones of the hindfoot. This is the largest bone of the foot. It articulates with the talus through the subtalar joint and with the cuboid to form the calcaneocuboid joint. Several muscles of the foot originate from the heel bone.
The posterior muscles of the leg (gastrocnemius and soleus) are attached to the tuberosity of the calcaneus via the Achilles tendon. In close proximity to the heel bone, on its way to the rest of the foot, there are several tendons, the tibial artery and a nerve. Being the main supporting bone of the foot, the heel bone can be damaged under excessive loads, for example, when falling from a height. Chronic overuse, such as during long-distance running and training, can lead to stress fractures of the calcaneus.
The calcaneus consists of the following parts:
- Anterior process
- Support of the talus
- Tuberosity (calcaneal tuberosity)
Each of these parts can be damaged by injury.
Scaphoid
The navicular bone is located anterior to the talus in the area of the inner edge of the foot and forms the talonavicular joint anterior to the ankle. The tibialis posterior muscle is attached to the tuberosity of the scaphoid bone by means of a powerful tendon. Approximately 10% of patients have an accessory scaphoid bone. The scaphoid bone articulates with the three sphenoid bones. Acute trauma can lead to a fracture of the scaphoid, and repeated overloads can lead to stress fractures.
Cuboid
The cuboid bone, as the name suggests, is cuboid in shape. It is located in front of the heel bone in the area of the outer (lateral) edge of the foot. Anterior to it are the 4th and 5th metatarsal bones. Fractures of the cuboid bone are common in jumpers, and stress fractures of this bone can develop with regular overuse.
Sphenoid bones
There are three sphenoid bones and they are called medial, middle and lateral. These bones form the arch of the midfoot. Medial and lateral sphenoid bones long middle sphenoid and form a fork in which the base of the second sphenoid bone is located, which in turn articulates with the middle sphenoid bone. This midfoot structure is the cornerstone of midfoot stability. The largest of the sphenoid bones is the medial sphenoid bone. The tendon of the tibialis anterior muscle is attached to this bone.
Metatarsals
There are five of these bones. They are all similar to each other and have wedge-shaped bases that articulate with the bones of the midfoot, tubular-shaped middle parts and rounded heads that articulate with the phalanges of the toes.
The 1st metatarsal bone is the most powerful and at the same time the shortest metatarsal bone. When walking, it takes on about 40% of the body weight. On the lower surface of the head of the 1st metatarsal bone there are two grooves along which two sesamoid bones slide.
The longest of the metatarsal bones is the 2nd metatarsal bone. At its base, a powerful Lisfranc ligament is attached, connecting it to the middle sphenoid bone. Damage to this ligament is often missed by doctors and can cause significant problems. Problems with the 1st metatarsal lead to a redistribution of the load on the 2nd metatarsal. Because this bone is unable to bear this additional load, a person develops a number of problems.
Metatarsal bones are a very common location for stress fractures that occur during constant physical overload, for example in people who run.
First finger (HALLUX)
The first finger is formed by two bones: the proximal and distal phalanges.
Small fingers
The small fingers are formed by three bones: the proximal, middle and distal phalanges. In a number of conditions we encounter problems with these very fingers.
Sesamoid bones
Under the head of the 1st metatarsal there are two sesamoid bones, each of which is located in its own groove
Under the head of the 1st metatarsal bone there are two small bones called sesamoids. These bones are located in the thickness of the flexor tendon of the 1st finger and are part of the plantar plate of the 1st MTP joint. The largest sesamoid bone in humans is the patella (kneecap), which is involved in the formation of the knee joint.
The sesamoid bones act as a fulcrum or lever for the tendon in which they are located. They play very important role in the normal biomechanics of the foot, limiting the friction force and taking on part of the load falling on the 1st MTP joint.
When moving, the sesamoid bones slide in their corresponding grooves on the lower surface of the head of the 1st metatarsal bone. In patients with hallux valgus deformity of the 1st toe, these bones are displaced in relation to their normal position. In patients with osteoarthritis, the sesamoid bones lose the ability to slide normally relative to the corresponding articular surface of the head of the 1st metatarsal bone.
The source of numerous problems with sesamoid bones is trauma, overload and damage to soft tissue.
A joint is the articulation of one bone with another. The foot and ankle include different types of joints.
- Synovial joints: the most common type of joint in the foot and ankle
- Fibrous joint: bones are held together by dense connective tissue - minimal mobility, high joint stability. An example of such a joint is the distal tibiofibular joint
- Cartilaginous articulation: bones connect to each other cartilaginous layer– the mobility of such joints is slightly higher than that of fibrous joints, but lower than that of synovial joints. Such joints are called synchondrosis.
Synovial joints allow for a wide variety of movements:
- Extension: extension (straightening) of a limb in a joint
- Flexion: bending a limb at a joint
- Abduction: movement directed away from the midline of the body
- Adduction: movement towards the midline of the body
- Rotation: circular movements around a fixed point
Some joints in the foot and ankle are relatively rigid and immobile and therefore more stable. Other joints, on the contrary, are much more mobile and therefore more unstable and susceptible to more high risk damage.
Stability is the ability of a particular anatomical structure to withstand physiological loads without undergoing deformation or becoming a source of pain.
Joint stability is determined by the static and dynamic components:
- Static stability: due in part to the anatomical shape of the joint
- Dynamic stability: muscles contract to stabilize joints, thereby providing them with dynamic protection
When muscles contract, they can either shorten (concentric contraction) or lengthen (eccentric contraction). It is eccentric muscle contraction that plays a particularly important role in the dynamic stabilization of joints.
The radiographs below show the major joints of the foot and ankle:
Joints of the foot and ankle on a lateral radiograph
Joints of the foot and ankle on an oblique radiograph
The small fingers consist of two joints - the proximal interphalangeal (PIP) and the distal interphalangeal (DIP)
- Ankle joint
- Subtalar joint
- Calcaneocuboid joint
- Talonavicular joint
- Scaphoid joint
- 1st tarsometatarsal joint (1st MTJ)
- 1st metatarsophalangeal joint (1st MTPJ)
- Interphalangeal joint (IPJ)
- 2nd metatarsophalangeal joint (2nd MTPJ)
- 3rd metatarsophalangeal joint (3rd MTPJ)
- 4th metatarsophalangeal joint (4th MTPJ)
- 5th metatarsophalangeal joint (5th MTP joint)
- 5th tarsometatarsal joint (5th MTJ)
- 4th tarsometatarsal joint (4th MTJ)
- 3rd tarsometatarsal joint (3rd MTJ)
- 2nd tarsometatarsal joint (2nd MTJ)
- Proximal interphalangeal joint of the 2nd finger (PMJ)
- Distal interphalangeal joint of the 2nd finger (DIP joint)
Ankle joint
The ankle joint is formed by the following bones:
- Talus
- Distal end of fibula
- Distal end of the tibia
The bony protrusions along the inner and outer surfaces of the ankle joint are called ankles and represent the expanded distal parts of the tibia (inner) and fibula (outer) bones. The posterior part of the distal end of the tibia is called the posterior malleolus. One or more ankles are often injured in ankle fractures.
Model of the ankle joint illustrating the location of the medial (inner) and lateral (outer) ankles
The main movement of the joint is the movement of the foot up and down (dorsiflexion and plantarflexion). Also in the ankle joint, a small amount of movement from side to side (inversion/eversion) and rotational movements are possible.
The static stability of the ankle joint is provided in part by the anatomical shape of the joint. Other static stabilizers of the joint are the tibiofibular syndesmosis, external and internal ligaments.
Dynamic stability is provided by muscles. The muscles contract and stabilize the joint, thereby providing it with dynamic protection.
When the muscles in the ankle joint contract, they can either shorten (concentric contraction) or lengthen (eccentric contraction). It is eccentric muscle contraction that plays a particularly important role in the dynamic stabilization of the joint.
One of the most important dynamic stabilizers of the ankle joint is the peroneus longus and brevis muscles, they play an important role in preventing damage to the external ligaments of the ankle joint.
Also, stability of the ankle joint is provided by the hip abductors (gluteus medius) and knee stabilizers. The stability of a person’s “whole body” is also important.
Subtalar joint
The subtalar joint is the articulation of the talus bone with the calcaneus. Functional anatomy and the function of this joint is still not completely clear.
It provides complex compound movements between the ankle joint at the top and the calcaneocuboid and talonavicular joints at the front. You could even say that the subtalar joint is unique in its functional characteristics foot joint. The subtalar joint helps to “lock” the midfoot when the foot pushes off the floor when walking. The subtalar joint is very important for walking on uneven surfaces.
Illustration of the major joints of the hindfoot: ankle, subtalar, calcaneocuboid and talonavicular
Triple joint
The talus, calcaneus, navicular and cuboid bones form three joints, or a triple joint:
- Subtalar joint – formed by the talus and calcaneus bones
- Calcaneocuboid joint – formed by the calcaneus and cuboid bones
- Talonavicular joint – formed by the talus and navicular bones
These three joints work cooperatively to produce complex movements of the foot. In a simplified version, we can say that they provide rotation of the foot inward (inversion) and outward (eversion).
Damage to any component of the triple joint (bone or joint) negatively affects the function of the entire joint.
Midfoot joints
The midfoot joints include:
- Scaphoid joint
- Intersphenoid joints
- Metatarsocuneiform joints
These joints are relatively fixed and immobile. They provide stability and are involved in the formation of the arch of the foot. They also serve as a link between the hind and forefoot.
1st PFS
The 1st MTP joint is the articulation between the head of the 1st metatarsal bone and the proximal phalanx of the 1st toe.
It is predominantly a trochlear joint, but some gliding and rotational movements are possible. This joint bears approximately 50% of the load of body weight during normal walking, and when running and jumping this load increases significantly. To withstand such loads, the 1st MTP joint must be stable.
The 1st PFS has both static and dynamic stabilizers. The structure of the bones that form the joint does not add stability to it: the articular surface of the proximal phalanx of the 1st finger is shallow. Static stabilization of the joint is provided by the capsule, collateral ligaments, plantar plate and sesamoid complex.
Dynamic stabilizers are the muscles: abductor 1st finger, adductor 1st finger, long extensor and flexor. Damage to the capsular-ligamentous apparatus of this joint is called “turf toe” in the English literature.
Small PFJs of the feet
The lesser MTP joints of the foot are the articulations of the heads of the metatarsal bones with the proximal phalanges of the toes.
Joints of the small toes
Each little toe consists of two joints:
- The proximal interphalangeal joint (PIPJ) is formed by the articulating surfaces of the proximal and middle phalanges
- The distal interphalangeal joint is formed by the articulating surfaces of the middle and distal phalanges.
More information regarding the anatomy of the lesser toes is provided below.
The anatomy of the little toes is not as simple as it seems, and is an example of the delicate balance of all the forces acting at the level of the forefoot. Full and painless functioning of the foot is impossible without the normal functioning of the toes.
Bones and joints
Bones and joints of a normal toe
- Distal phalanx
- Middle phalanx
- Proximal phalanx
- Metatarsal
Muscles
Normally, we can observe the presence of a delicate balance between the work of the external (muscles located on the lower leg, the tendons of which are attached to the toes) and the intrinsic (muscles located on the foot, the tendons of which are also attached to the toes) muscles of the foot.
Three main extrinsic muscles and their tendons:
- Extensor digitorum longus (EDL) – attaches to the distal phalanx and is responsible for finger extension
- Flexor digitorum longus (FDL) – attaches to the distal phalanx and is responsible for flexing the DMJ
- Flexor digitorum brevis (FDB) – attaches to the middle phalanx and is responsible for flexing the PIP joint.
Three main external tendons of the toes and their points of insertion
The foot contains a number of intrinsic foot muscles. These muscles play an important role in stabilizing the arches of the feet, ensuring pronation of the foot and are involved in the movement of the foot during walking.
The following intrinsic muscles of the foot play an important role in the work of the small toes:
- Vermiforms that attach to the extensor tendon (see below), pulling it tight
- Plantar and dorsal interosseous muscles, responsible for spreading and closing the fingers, as well as for their flexion in the MCP joint, they are also attached to the extensor tendon stretch
On the way to their insertion points on the phalanges of the fingers, the extensor digitorum longus and brevis tendons at the level of the PFJ and proximal phalanx of the digit are woven into a formation called the extensor tendon sprain. This is a very important anatomical formation of the finger. It is a triangular plate resembling a scarf, and serves as the point of attachment of the long extensor finger and the intrinsic muscles of the foot: the lumbrical, plantar and dorsal interosseous. The tendon stretch on the lower surface of the toe is intertwined with fibers from the plantar plate and the PFJ capsule. Contraction of the intrinsic foot muscles in a neutral toe position results in flexion of the toe at the MCP joint because the muscle insertion points are located below the axis of the MTP joint. Due to the fact that the intrinsic muscles are attached to the extensor tendon, when they contract, they pull on the stretch, which in turn straightens the finger at the DMJ and PIPJ.
When the intrinsic muscles of the foot contract, the pull of the extensor digitorum longus is evenly distributed between all joints of the toe, which leads to extension of the toe in the DMJ and PMJ (straightening)
Contraction of the intrinsic foot muscles pulls on the extensor tendon, which in turn straightens the toe at the DMJ and PIPJ.
In the absence of contraction of the intrinsic muscles of the foot, the pull of the long extensor of the finger leads to hyperextension of the finger in the PFJ, and extension in the DMFC and PIPJ does not occur; in these joints, the finger, on the contrary, bends due to the pull of the long flexors (FDL and FDB).
The result of the work of the external muscles of the foot in the absence of balance on the part of the own muscles of the foot
PFS stability
Due to their anatomical features, the MCP joints do not have a reserve of their own stability. The heads of the metatarsal bones are round in shape, and the bases proximal phalanges- the shape of a flat dish.
The shape of the PFS is ensured by static and dynamic stabilizers. Static stabilizers include the joint capsule, lateral ligaments and plantar plate. Dynamic stabilizers are the flexor and extensor muscles and tendons.
The lateral (collateral) ligaments attach to the metatarsal heads and the lateral surfaces of the proximal phalanges, resisting excess valgus/varus (side to side) loads. The collateral ligament consists of two parts: the collateral (or true collateral) ligament itself, connecting the head of the metatarsal bone to the base of the proximal phalanx, and the accessory collateral ligament, which attaches to the plantar plate.
The plantar plate and plantar fascia resist excessive dorsal displacement of the toe. The plantar plate is a fibrocartilaginous thickening of the plantar portion of the MCP joint capsule. It is a direct continuation of the periosteum (superficial layer of bone) of the base of the proximal phalanx. It is attached to the head of the metatarsal bone through the collateral ligament.
Ligaments are fibrous structures that provide stability to joints. They connect one bone to another.
Top view of the foot. The structures colored blue are the ligaments and joint capsules that hold the bones next to each other
Ligaments of the foot and ankle joint from the outer (lateral) surface
Ligaments of the foot and ankle joint from the inner (medial) surface
- Anterior talofibular ligament
- Calcaneofibular ligament
- Posterior talofibular ligament
- Midfoot ligaments
- Deltoid ligament
- Spring bundle
- Tarsometatarsal ligaments
- Capsule 1st PFS
- PFJ capsules of the small toes
Syndesmosis
Formally, the syndesmosis is considered a joint, but at the same time it is formed by four ligamentous structures. It provides stability to the ankle joint by holding the distal ends of the tibia together and resisting rotational, lateral and axial loads.
- Anterior inferior tibiofibular ligament
- Posterior inferior tibiofibular ligament
- Transverse tibiofibular ligament
- Interosseous ligament
The complex of these ligaments can be damaged in high ligamentous ankle injuries.
Lateral ankle ligaments
There are three external ligaments of the ankle joint: the anterior talofibular, calcaneofibular and posterior talofibular. They provide stability to the ankle joint and prevent it from rotating inwards (inversion).
The anterior talofibular ligament is one of the most susceptible ligaments in the ankle and is a common cause of lateral ankle instability. Damage to this ligament occurs during forced plantar flexion and inversion of the foot.
The second most common injury is the calcaneofibular ligament. Damage to this joint aggravates ankle instability and may also cause subtalar joint instability.
Medial ankle ligaments
These are the largest ligaments in the foot and the most important stabilizers of the ankle joint. These ligaments include the deltoid and spring ligament complexes.
- Deltoid ligament
- The deep portion of this ligament originates from the medial malleolus and is attached to the medial surface of the talus
- The superficial portion of the deltoid ligament consists of three parts
- Part attaching to the scaphoid and spring ligament
- Part attaching to the talus support of the calcaneus
- Part attaching to the medial tubercle of the calcaneus
The deep portion of the deltoid ligament resists lateral displacement of the talus and its external rotation. The superficial portion of the deltoid ligament primarily resists eversion of the hindfoot. Damage to this ligament becomes a source of pain in the area of the inner surface of the ankle joint and its instability.
- Spring bundle
- Located on the bottom surface of the foot, starts from the heel bone and attaches to the navicular bone
- The lower surface of the head of the talus forms an articulation with the spring ligament
- The distal part and inferior surface of the spring ligament are united by fibers with the tendon of the tibialis posterior muscle, and they are attached together to the scaphoid bone
- The proximal and internal fibers of the spring ligament are intertwined with the fibers of the deltoid ligament
The spring ligament is a very important anatomical structure that is involved in maintaining the arch of the foot (internal longitudinal arch), and also provides support for the head of the talus under load. Damage to this ligament leads to the development of progressive flat feet and pain.
Lisfranc ligament
The Lisfranc ligament is an important ligament connecting the medial cuneiform bone to the base of the 2nd metatarsal. This ligament maintains the normal anatomical relationship between the bones of the metatarsus and the bones of the midfoot. The ligament can be damaged as a result of overstretching or fracture, and doctors often miss these injuries, which becomes a source of problems.
The plantar plate is a fibrocartilaginous thickening of the plantar capsule of the MCP joint. It is a continuation of the periosteum (superficial layer of bone) of the base of the proximal phalanx of the finger. It is attached to the head of the metatarsal bone through collateral ligaments (true and accessory). The plantar plate and plantar fascia provide stability to the toes, preventing them from moving upward.
In the area of the 1st MCP joint, the plantar plate contains the medial and lateral sesamoid bones.
Injury to this ligament is thought to play a role in the formation of PFJ instability and crossed toe.
Muscles are anatomical formations that have the ability to contract, while ensuring movement in the joints, performing certain work and maintaining the position of the body in space. Tendons are structures through which muscles are attached to bones. In the area of the foot and ankle, the tendons, with the exception of the Achilles tendon, are named after their corresponding muscles.
The muscles responsible for the functioning of the foot and ankle joint can be divided into external ones, i.e. those located on the back or front surface of the lower leg, and those located on the dorsal (upper) or plantar (lower) surface of the foot.
An exception is the gastrocnemius muscle, which starts on the back of the lower third of the thigh just above the knee joint and attaches to the heel bone.
Muscles and tendons of the leg
Calf muscle
This powerful calf muscle consists of two heads, medial and lateral, which originate on the posterior surface of the distal end of the thigh and are attached by the Achilles tendon to the calcaneus.
The gastrocnemius muscle is involved in running, jumping, and all types of activities that involve high-intensity stress on the lower extremities.
Together with the soleus muscle, it forms the calf muscle, called the triceps surae muscle. Function calf muscle is the flexion of the foot and ankle joint downwards (plantar flexion).
Forceful dorsiflexion of the foot can cause damage to this muscle.
Soleus muscle
This muscle starts from the tibia below the level of the knee joint and is located under the gastrocnemius muscle. Distally, its tendon unites with the gastrocnemius tendon to form the Achilles tendon. Like the gastrocnemius muscle, the main function of this muscle is plantar flexion of the foot.
The calf muscle is involved in walking, dancing, and maintaining an upright body position when we stand. Also, one of its important functions is to ensure blood flow through the veins from the lower limb to the heart.
Plantaris muscle
It is a small muscle that originates along the lateral head of the gastrocnemius muscle. The tendon of this muscle is the longest tendon in the human body. It is a weak but still plantar flexor of the foot. Damage to this muscle can occur when playing sports.
Achilles tendon
The Achilles tendon is formed at the mid-calf level by the gastrocnemius and soleus muscles and is attached to the heel bone. This is the most powerful and durable tendon in the human body.
It is subjected to the most significant loads compared to all other tendons. When running and jumping, the tendon is subjected to loads that are 8 times greater than body weight, and when walking - 4 times.
Through the Achilles tendon, the gastrocnemius and soleus muscles perform plantar flexion of the foot and ankle joint.
The tendon consists of three parts:
- Musculotendinous part (proximal part of the tendon, at the level of which muscle fibers turn into tendon fibers)
- Non-insertional part (body) of the Achilles tendon
The blood supply to the Achilles tendon is quite poor compared to other anatomical structures. The tendon in its upper section receives blood supply from the muscles that form the tendon, and below - from the heel bone to which it is attached. The middle part of the tendon is supplied with blood by the branches of the peroneal artery and this blood supply is the poorest, so it is not surprising that this part of the tendon is most susceptible to damage. The Achilles tendon is surrounded by a soft tissue sheath called the paratenon. The middle part of the tendon receives its blood supply precisely through this sheath. The paratenon allows the Achilles tendon to glide relative to surrounding tissues for up to 1.5 cm.
Anterior to the Achilles tendon is the Kager fat pad, which performs important function protection of the Achilles tendon.
- Musculotendinous part
- Kager fat body
- Non-insertional part of the Achilles tendon
- Insertion part of the Achilles tendon
External muscles and tendons of the foot
Tibialis posterior muscle
The tibialis posterior muscle starts from the posterior surface of the tibia and fibula (under the gastrocnemius muscle in the posterior muscle sheath of the lower leg). The tendon of this muscle on its way to the foot bends around the back of the inner ankle.
The main point of attachment of the muscle is the tuberosity of the scaphoid bone and the medial sphenoid bone. Also from the tendon there are bundles that attach to the bases of the 2nd, 3rd and 4th metatarsal bones, the intermediate and lateral cuneiform bones and the cuboid bone.
The muscle and its tendon play an important role in the formation and maintenance of the inner arch of the foot.
Contraction of the tibialis posterior muscle causes inversion (inward rotation) of the foot and plantar flexion of the foot and ankle.
Dysfunction of the tibialis posterior muscle, incl. rupture of its tendon may cause acquired flat feet.
Tibialis anterior muscle
The tibialis anterior muscle originates from the upper two-thirds of the outer surface of the tibia. Its tendon attaches to the medial cuneiform and 1st metatarsal bones of the foot.
The muscle performs dorsiflexion and inversion of the foot.
Damage to general peroneal nerve innervating the muscle or tendon of this muscle leads to foot drop.
Peroneus brevis muscle
The peroneus brevis muscle originates from the lower two-thirds of the outer surface of the fibula. Its tendon passes behind the lateral malleolus, runs along the outer surface of the calcaneus, located above the tendon of the long peroneal muscle, and is attached to the tuberosity of the base of the 5th metatarsal bone.
The muscle performs eversion (outward rotation) of the foot and provides dynamic stabilization of the outer part of the foot and ankle joint. Trauma to the foot accompanied by inversion can lead to damage to the tendon of this muscle.
A – peroneus brevis tendon, B – peroneus longus tendon
Peroneus longus muscle
The peroneus longus muscle originates from the fibula above the peroneus brevis muscle. Its tendon also passes behind the lateral malleolus, continues onto the foot and attaches to the medial cuneiform and 1st metatarsal bones.
The main function of the muscle is plantar flexion of the 1st ray of the foot. It also performs plantar flexion and eversion of the foot. The muscle is involved in maintaining the transverse arch of the foot and provides lateral dynamic stability of the ankle joint.
Flexor digitorum longus 1 (FHL)
The muscle begins on the back surface of the leg (posterior muscle sheath) and attaches to the lower (plantar) surface of the distal phalanx of the 1st finger.
The muscle performs flexion (plantar flexion) and inversion of the foot. She also bends the 1st finger.
Extensor digitorum longus 1 (EHL)
This muscle is located between the tibialis anterior muscle and the extensor digitorum longus muscle in the anterior muscle compartment of the lower leg. It is attached to the base of the distal phalanx of the 1st finger. The long extensor of the 1st toe extends (straightens and raises) the first toe, performs dorsiflexion of the foot and is involved in eversion and inversion of the foot.
Flexor digitorum longus (FDL)
It is one of three muscles that originate on the back of the lower leg (the posterior muscle sheath), the other two being the flexor digitorum longus and the tibialis posterior. The flexor digitorum longus attaches to the inferior (plantar) surface of the distal phalanges of the small toes.
The muscle flexes the small toes.
Extensor digitorum longus (EDL)
The muscle begins with a wide base on the anterior surface of the tibia and fibula and the interosseous membrane. On the foot it is divided into 4 tendons, which are attached to the 4 small toes. Each tendon at the level of the MCP joint is divided into 3 bundles, the central bundle is attached to the base of the middle phalanx, the two lateral bundles are united and attached to the distal phalanx.
The main function of the extensor digitorum longus is to straighten the fingers. However, it is also involved in dorsiflexion of the foot and ankle.
Own muscles and tendons of the foot
Flexor digitorum brevis (FDB)
The muscle starts from the internal (medial) process of the calcaneus and the central part of the plantar fascia. It is attached to all 4 small toes. At the level of the PFJ, each muscle tendon is divided into 2 bundles, each of which goes around the tendon of the long flexor of the finger and is attached to the middle phalanges of 2-5 fingers.
The muscle performs flexion (plantar flexion) of the middle phalanges of the fingers in the PIPJ. As the muscle continues to contract, the proximal phalanges flex in the MCP joint.
Vermiform muscles
These are 4 small muscles starting from the 4 flexor tendons on the foot. The tendon of each lumbrical muscle is attached to the tendon extension of the long extensor muscles on the dorsum of the proximal phalanges of the fingers. Contraction of the lumbrical muscles leads to extension of the fingers in the PIPJ and DIPJ. Because the tendons are located below the point of rotation of the MCP joint, they also perform flexion at these joints.
Interosseous muscles
The interosseous muscles of the foot are divided into dorsal and plantar.
The 4 dorsal interosseous muscles originate from the proximal halves of the lateral surfaces of the metatarsals. Their tendons are attached to the bases of the proximal phalanges of the 2nd, 3rd and 4th fingers and to the aponeurosis of the extensor digitorum longus tendon (not to the extensor tendon extension).
The dorsal interosseous muscles perform abduction (abduction) and, together with the plantar interosseous muscles, participate in flexion of the fingers at the MCP joint.
The 3 plantar interosseous muscles start from the 3-5 metatarsal bones; they perform closure (adduction) of the toes.
Together, the dorsal and plantar interosseous muscles stabilize the little toes. They are also involved in maintaining the forefoot arch and, to a small extent, in maintaining the medial and lateral longitudinal arches of the foot.
The nerves provide sensory innervation to the foot and ankle. They also “tell” our muscles when to contract and when to relax.
Sensory innervation of the foot
- Saphenous nerve
- Deep peroneal nerve
- Sural nerve
Superficial peroneal nerve
This nerve is located in the outer muscular sheath of the leg and innervates the muscles located here - the long and short peroneus. This nerve also innervates most of the skin on the dorsum of the foot, with the exception of the interdigital space between the 1st and 2nd toes, which is innervated by the deep peroneal nerve.
Deep peroneal nerve
This nerve enters through the extensor digitorum longus and runs down the surface of the interosseous membrane. It then crosses the tibia and exits onto the dorsum of the foot. The nerve innervates the muscles of the anterior muscular sheath of the leg and dorsum of the foot. It also innervates a small area of skin between the 1st and 2nd fingers.
Tibial nerve
This nerve is a branch sciatic nerve. It is located between the two heads of the gastrocnemius muscle. At the level of the ankle joint, it curves around the back of the inner malleolus and continues onto the foot. The nerve innervates all the muscles of the posterior muscular sheath of the leg and is responsible for the sensitivity of the plantar surface of the foot.
Saphenous nerve
This nerve is a branch of the femoral nerve and descends along the lower leg to the inner surface of the foot, innervating the skin of the inner edge of the foot and ankle joint.
Sural nerve
This nerve is located between the two heads of the gastrocnemius muscle, but enters the foot behind the outer malleolus. It innervates the skin of the outer surface of the foot and ankle joint.
Plantar interdigital nerves
These nerves are branches of the medial and lateral plantar nerves. They innervate the skin and nail beds of the toes.
The plantar fascia is a thin layer connective tissue, supporting the arch of the foot. It starts from the lower surface of the heel bone and continues towards all 5 toes. Here it is divided into superficial and deep layers. The superficial layer is intimately connected with the deep layers of the skin and subcutaneous tissue. The deep layer is attached to the plantar plate.
The Achilles tendon is characterized by the presence of a fascial connection with the plantar fascia of the foot. A tight Achilles tendon also causes tightness in the plantar fascia.
The plantar fascia is a multifunctional mechanism. It supports the arch of the foot. It also accounts for about 15% of the load on the foot. When walking and standing, the plantar fascia stretches and acts as a spring. She also participates in the operation of the “windlass mechanism”.
The term "windlass" comes from marine engineering and is a winch-type mechanism in the form of a horizontal shaft on which a cable is wound. The plantar fascia in this sense resembles a cable attached to the heel bone and metatarsophalangeal joints. Dorsiflexion of the toes during stride tightens the plantar fascia around the metatarsal heads. This leads to a reduction in the distance between the heel bone and the metatarsal bones, raising the medial longitudinal arch of the foot, and ensures that the foot acts as an effective lever.
The weight of the body applied to the foot causes tension in the plantar fascia. The tense fascia prevents the divergence of the calcaneus and metatarsal bones and thereby preserves the medial longitudinal arch.
The plantar fascia, due to the peculiarities of its structure (yellow line), prevents the arch of the foot from collapsing. Yellow arrows indicate the tension force of the fascia, balancing the weight of the body (red arrow) and the counteracting force of repulsion from the surface (blue arrows)
The plantar fascia (white arrow) connects to the Achilles tendon (red arrow) through fascial fibers (yellow arrow).
A vault is defined as “a load-bearing arc-shaped floor connecting the walls or supports of a bridge, roof, or structure located above it.”
The foot is characterized by the presence of several arches, each of which has an arched shape and creates the conditions for the foot to be able to withstand the load placed on it at rest, when walking or running. The arches of the foot are formed by the bones of the metatarsus and tarsus, ligaments, tendons and plantar fascia.
Medial longitudinal arch of the foot
- Longitudinal arch
- Medial
- Lateral
- Transverse arch
Along with supporting the anatomy of the foot during weight bearing, the medial arch of the foot also acts like a spring, redistributing the load and minimizing wear and damage to the anatomical structures of the foot. It also stores some of the energy applied to the foot while walking, returning it for next step, thereby reducing the energy consumed by the body for walking and running.
The shape of a person's foot and especially its arches allows us to judge what problems this person may have. A person with a low longitudinal arch will have flat feet, and when walking, such people's feet are likely to turn outward (pronated). Possible problems these people may have heel pain, plantar fasciitis, and inner arch pain. People with flat feet may have difficulty supporting their own weight when standing on their toes. Excessive foot pronation can also cause knee and hip pain.
People who live with flat feet their entire lives may not have all the problems described. Acquired or unilateral flatfoot (asymmetrical changes) is most likely based on some specific cause, which requires additional examination and, possibly, treatment.
When the height of the longitudinal arch of the foot increases, they speak of a hollow foot. When standing and walking, the feet of such people turn inward (supination). High arches can also cause plantar fasciitis because they overload the plantar fascia. People with pes cavus are at risk for developing ankle instability, stress injuries, and 5th metatarsal fractures.
The talus bone consists of a head, neck and body. The head has an articular scaphoid surface (facies articularis navicularis) for articulation with the scaphoid bone. The upper surface of the body is represented by a block (trochlea) for articulation with the bones of the lower leg. On both sides of the block there are articular platforms - places of articulation with the medial and lateral ankles (facies articulares medialis et lateralis). On the lower surface of the body there is a deep groove (sulcus tali); in front and behind it there are articular platforms for articulation with the calcaneus (facies articulates calcaneae anterior, media et posterior) (Fig. 97).
97. Talus.
A - bottom view; B - rear view: 1 - trochlea tali; 2 - facies maleolaris lateralis; 3 - processus lateralis tali; 4 - processus posterior tali; 5 - facies articularis calcanea posterior; 6 - facies articularis calcanea media; 7 - facies malleolaris medialis; 8 - facies articularis calcanea anterior
Calcaneus
The calcaneus (calcaneus) on the upper surface contains three platforms (facies articulares talares anterior, media et posterior) for connection with the talus. The last two are separated by a groove (sulcus calcaneus). Together, when the groove of the calcaneus combines with the groove of the talus, the sinus tarsi (sinus tarsi) is formed, where there is an interosseous ligament. At the back, the bone passes into the calcaneal tuber (tuber calcanei), and in the anterior part of the bone there is a saddle-shaped articular surface (facies articularis cuboidea) for connection with the cuboid bone. On the medial side of the bone there is a protrusion - the support of the talus (sustentaculum tali) (Fig. 98).
98. Right calcaneus.
1 - facies articularis talaris posterior;
2 - tuber calcanei;
3 - sustentaculum tali;
4 - facies articularis talaris media;
5 - facies articularis talaris anterior;
6 - facies articularis cuboidea.
Scaphoid
The navicular bone (os naviculare) is located in the area of the inner edge of the foot, has a concave articular surface for the head of the talus and a convex one for connection with the sphenoid bones. On its lower surface there is a pronounced tuberosity (tuberositas ossis navicularis)
Sphenoid bones
Three wedge-shaped bones (ossa cuneiformia) are arranged in a row, starting from the medial edge of the foot: os cuneiforme mediale, intermedium et laterale (Fig. 99).
Cuboid
The cuboid bone (os cuboideum) is located on the lateral edge of the foot. On its lower surface there is a tuberosity (tuberositas ossis cuboidei) and a notch (sulcus tendineus musculi peronei longi) from the pressure of the peroneus longus tendon (Fig. 99).
99. Bones of the right foot.
1 - calcaneus;
2 - talus;
3 - os cuboideum;
4 - os naviculare;
5 - os cuneiforme laterale;
6 - os cuneiforme intermedium;
7 - os cuneiforme mediale;
8 - os metatarsale 1;
9 - phalanx proximalis;
10 - phalanx media;
11 - phalanx distalis.
Metatarsus
The metatarsus consists of five metatarsal bones (ossa metatarsalia I-V). Its parts are distinguished: base (basis), body (corpus) and at the distal end the head. In the area of the base and head there are articular platforms. On the lower surface of the base of the first metatarsal bone and on the lateral surface of the base of the fifth bone there are tuberosities (tuberositas ossis matatarsalis I et V) (Fig. 99).
One sesamoid bone is adjacent to the lower lateral and medial surfaces of the heads of the first and fifth metatarsal bones.
Toe bones
The toes (digitorum pedis) consist of three phalanges (phalanges proximalis, media et distalis), which are much shorter than the phalanges of the fingers. The big toe has two phalanges (phalanges proximalis et distalis), the rest have three. Each phalanx has a body and two ends: proximal - the base and distal - the head. At the distal end of the distal phalanx there is a tubercle (tuberositas phalangis distalis).
Ossification. All bones of the foot go through webbed, cartilaginous and bony stages of development. Ossification nuclei appear in the calcaneus at VI months, in the talus at VI-VII months, in the cuboid bone at IX months intrauterine development, in the medial sphenoid - in the 2nd year of life, in the sphenoid - in the 3rd year, in the sphenoid (lateral) - in the 1st year, in the scaphoid - in the 4th year. At the 3rd - 7th year of life, 1-2 independent ossification nuclei appear in the calcaneal tubercle, which in girls merge with the body of the calcaneus by 11-12 years, in boys - by 15 years.
In the phalanges of the toes, bone points are formed in the diaphysis of the phalanges in the 10-13th week of intrauterine development, in the proximal epiphysis in the 1st - 3rd year, and in the head of the metatarsal bones - in the 1st year.
Sesamoid bones
Sesamoid bones include those bones that are located in muscle tendons. The largest is the patella.
Sesamoid bones in the area of location of the 1st and 5th metatarsophalangeal joints occur in girls between 8-12 years, in boys - between 11-13 years. Similar bones also appear on the hand, most often in the first carpometacarpal joint.
Anomalies. Anomalies of the bones of the lower extremity include accessory, unstable bones of the foot. As a rule, there are about nine such bones: 1) bones between the medial and intermediate sphenoid bones; 2, 3) bones between the I and II metatarsal bones; 4) the bone located above the scaphoid; 5) the bone lying above the talus; 6) bone at the site where the tibialis tendon bends through the cuboid bone; 7) bone representing the unconnected point of the tubercle of the scaphoid; 8) an independent bony point of the posterior process of the talus; 9) an independent bony point of the medial malleolus.
- Bone base of the foot
- Ankle joint
- Other joints of the foot and their ligaments
- Foot muscle groups
- Neurovascular formations of the foot area
The foot is the lower anatomical part of the leg. In medical terminology, it is located most distally, that is, away from the center of the body or the place of attachment to the body. The skeleton of the foot is quite complex and ideally matches the function assigned to the human feet. They went through a long evolution to adapt to walking upright.
Bone base of the foot
On the foot, there are areas formed by certain bone groups: the tarsal metatarsus and the phalanges of the fingers.
The tarsus is the section of the foot located immediately below the ankle joint area. From above it is limited by a circular line drawn through the posterior edge of the heel bone along the lower edges of the ankles, which corresponds to upper limit human feet. The tarsus consists of seven spongy bones, which are arranged in two rows:
- The back row is the same part that is the main structure of the heel and consists of two relatively massive bones of a complex “irregular” shape: the talus and the calcaneus.
- The front row is divided into two more sections - the one located with inside the foot (medial) and the one located on the outer edge (lateral). The first includes three wedge-shaped bones and the scaphoid, which occupies an intermediate position between them and the head of the talus. The second is represented by the cuboid alone - it is located between the 4th and 5th metatarsal bones in front and the calcaneus in the back.
The metatarsus occupies an intermediate position among the three regions. Here the variety of sizes, shapes and names stops abruptly. It is built of five bones, which are very similar to those located in the metacarpus of the upper limb. They consist of several parts:
- grounds;
- bodies;
- heads.
The phalanges of the toes are the smallest of all the bones of the foot. Each finger is formed from three such bones, with the exception of the big one - the structure of the human foot is such that it contains only two phalanges. It is also called the first, it is from here that the numbering of the toes begins - from I to V.
In addition to the listed bones, there are also special sesamoid bones, which are small in size and serve to protect the tendons and increase their leverage. They can be located between the phalanges thumb, as well as in the area of the articulations of the bones of the metatarsus and phalanges.
Ankle joint
The anatomy of the human foot is rich in interosseous joints, which are mostly represented by joints - they are strengthened by ligaments. Before examining each one individually, it is necessary to summarize the general information about what a joint is. This is a synovial joint capable of participating in a wide variety of movements depending on its structure. It may contain the following articular elements:
- surfaces;
- cartilage;
- cavity;
- capsule;
- discs and menisci;
- lip.
It should be remembered that the joint is at the peak of development among all other interosseous joints; in the structure of the foot, one of them occupies a special position - it is of the largest size and is quite complex in structure. Ankle joint. It is so large and powerful that it has been isolated into a separate anatomical region - the “ankle joint area”. Formed from certain parts:
- The articular surfaces are formed with the help of the tibia and fibula, their lower ends - they form a recess for the block of the talus, covering it on several sides. The block is also involved in the construction of the joint. There are 6 surfaces in total.
- Hyaline cartilage covers the outer parts of the connecting surfaces, preventing them from directly touching. It forms the joint space, defined on x-ray as the distance between the bones.
- The joint capsule is attached just along the edge of the cartilage and in front captures the area of the talus - its neck.
Do not forget about the presence of the ligamentous apparatus, which often accompanies interosseous joints. The ankle joint is strengthened by the medial and lateral accessory ligaments. The first resembles the letter delta from the Greek alphabet: it is attached above to the inner malleolus, below - to the navicular, talus and calcaneus. The second comes from the outer ankle, diverging in three directions, forming ligaments.
This joint is defined as a trochlear joint: it moves around the frontal axis, only when flexed can the human “paw” make sideways movements.
Other joints of the foot and their ligaments
There are many movable joints directly between the bones of the human foot. In the tarsal region alone there are four:
- Subtalar joint. It has a cylindrical shape and limited mobility. The joint is supported by three connective tissue cords. Differs in functional integrity from a clinical point of view.
- The talocaleonavicular joint is considered a ball-and-socket joint, but is only movable in one sagittal plane around its axis.
- The calcaneocuboid joint is involved in motor activity the two above. Together with the previous joint, it is called the “transverse tarsal joint.” It is surrounded by two ligaments, which are a continuation of the so-called bifurcated ligament. It is considered the “key” of the joint, since it must be cut in order to gain full access to it.
- Wedge-navicular joint. It is easy to guess what articular surfaces it consists of - all three sphenoid bones take part in their formation in front. The synovial joint is strengthened by several groups of tarsal ligaments.
The anatomy of the foot is complex and diverse. In addition to the above joints of the lower part of the human leg, there are five tarsometatarsal, metatarsophalangeal and interphalangeal joints. The latter in the area of the fifth finger does not necessarily have to be present, since the middle and distal phalanx of this finger can be fused. There are also intermetatarsal joints, strengthened by the dorsal, interosseous and plantar ligaments of the metatarsus. The ligamentous and articular apparatus of the foot must be protected, since each of its elements performs a specific function that ensures the most comfortable movement in this area.
Foot muscle groups
The structure of the foot, as is known, is not limited to the skeleton. The muscular composition of the human foot area, like the articular one, is very diverse.
The table shows the muscles and their groups that descend from the lower leg to the foot.
| Group | Muscle name | Function (for foot movement) |
| Front | Extensor pollicis longus | Extension of the big toe, as well as the foot as a whole, while raising its inner edge |
| Extensor digitorum longus | Participates in extension, elevation of the outer edge, abduction to the side | |
| Anterior tibial | Extension, raises the inner edge | |
| Lateral | Long fibular | Pronation, abduction, flexion |
| Short fibular | ||
| Rear | ||
| Surface layer | Forms the Achilles tendon | Motor activity of the ankle joint |
| Deep layer | Flexor digitorum longus | Supination and flexion |
| Posterior tibial | Adduction and flexion | |
| Flexor hallucis longus | Can bend not only the first finger, but also play a role in bending others |
Considering the serious functional role of the foot, it is easy to assume that in addition to the above-mentioned tendons attached to its bones, there are short muscles by analogy with the upper limbs. The structure of the human foot suggests the presence of certain groups:
- lateral;
- average;
- dorsal muscles;
- plantar muscles.
It is important to remember that anatomical terminology is structured in such a way that often the very name of the muscle contains its function. Often movements are carried out by several of them at once. If one muscle is damaged, its role can be partially compensated by another that performs a similar function.
Neurovascular formations of the foot area
In humans, the body is structured in such a way that often blood vessels and nerves extend throughout the body, accompanying each other. Such relationships came to be called neurovascular bundles. They are located in almost every region.
Thus, the tibial bundle in front is represented by the following formations:
- anterior tibial artery;
- two anterior tibial veins;
- deep peroneal nerve.
When they move to the foot, their names change: dorsal artery of the foot, dorsal veins of the foot, and two dorsal digital nerves, respectively. Arterial vessel branches into many branches, supplying blood to different areas of the foot. The nerve is responsible only for the movement of the extensor digitorum brevis and the sensitivity of the skin of the sides of the fingers facing each other in the area of the first interdigital space. The skin of the remaining areas of the phalanges from the rear is innervated by the branches of the superficial peroneal nerve, coming from the side of the lateral muscles of the leg.
The posterior, so-called tibial bundle consists of certain components:
- posterior tibial artery;
- two veins of the same name;
- tibial nerve.
In the lower part of the leg, the artery gives off two branches: internal (medial) and external (lateral) plantar, which form two arterial arches. The tibial nerve gives off its branches to various areas of the sole, also directing one to the lateral side of the dorsum of the foot.
The complex structure of the human foot is accompanied by an equally intricate course of nerves.
Knowledge of the anatomy of the foot is necessary for a correct understanding of almost any pathology, one way or another, associated with this area of the lower limb.
Tags: Bones, Treatment of joints
On the plantar side of the metatarsophalangeal joint of the first toe, in the structure of the flexor apparatus there are two small bones smaller than a pea. Despite the fact that the bones are very small in size, they play a huge role during walking, running, jumping and other stress on the foot. If the sesamoid bones are involved in any pathological process, then they become a source severe pain, significantly worsening the patient's quality of life.
Anatomy
At the base of the first toe is the first metatarsophalangeal joint, which is important from a functional point of view. Two small sesamoid bones are located on the plantar side of this joint: one is located on the inside, the other on the outside. The sesamoid bones are located inside the flexor tendons of the first finger. These structures together form the flexor apparatus of the first toe. Since the first finger bears heavy loads, these loads are performed due to the flexion apparatus. Sesamoid bones increase the leverage of the flexor tendons on the phalanges of the first finger, and also reduce the force of friction between the tendons and soft tissues in the position of extension of the first finger.
Causes
Pain syndrome can develop for various reasons. One of the reasons is overload of the ligamentous apparatus of the sesamoid bones. This condition may be called sesamoiditis. Overload most often develops after excessive running or dancing.
Another cause of pain associated with the sesamoid bones is fractures. Fractures can occur when landing directly on the first metatarsophalangeal joint of the foot. So-called stress fractures of the sesamoid bones may also occur. Stress fractures occur due to constant exposure to large loads on the sesamoid bone apparatus. This is typical for athletes; athletes are most often affected.
Another reason is arthrosis of the joint between the head of the first metatarsal bone and the sesamoid bones. When the big toe moves, the sesamoid bones slide anteriorly and posteriorly along the plantar surface of the head of the first metatarsal bone. Like other joints in the body, this joint can develop arthrosis. Arthrosis in this joint typical for patients with high longitudinal arches of the foot. With a high longitudinal arch of the foot, the apparatus of the sesamoid bones is under greater tension and the joints of the sesamoid bones are subject to greater load. Eventually, the cartilage of the sesamoids and the head of the first metatarsal begins to deteriorate.
A rare cause is a disruption of the blood supply to the sesamoid bones, resulting in disruption of the bone structure. This condition is called avascular necrosis of the sesamoid bone. In this case, calcium deposits may additionally form in the soft tissues around the first metatarsophalangeal joint.
Sometimes pain from the plantar surface comes from additional soft tissue formations under the big toe. For example, plantar keratosis can cause pain on the plantar aspect of the first metatarsophalangeal joint.
Symptoms
Patients with pathology of the sesamoid bones usually feel aching pain from the plantar surface of the metatarsophalangeal joint of the first toe. When touched from the plantar side, the pain intensifies. Movement in the thumb joint is often limited. Patients notice that when walking, the pain intensifies before the foot pushes off for the next step. From time to time, the first metatarsophalangeal joint may become stuck or click, which increases pain. After rest, the pain goes away or weakens. Some patients report numbness in the area of the first and second toes.
Diagnosis
The doctor will ask many questions about the development of the disease. You will be asked about your current complaints and past foot problems. The doctor will examine your feet. The examination may be a little painful, but it is necessary to determine painful points, check your finger movements. The patient may be asked to walk around the room.
Compliance is mandatory x-ray(radiographs). Several projections are performed. One of them is the axial one, on which the sesamoid bones are clearly visible. This projection requires special placement and the X-ray beam comes at an angle.
An x-ray may reveal that the sesamoid bone is composed of two or more separate bones, as if it were a fracture, but the boundaries between them are smooth. This is normal and can occur in every tenth person. The x-ray evaluates the position of the sesamoid bones, as well as the space (articulation) between the metatarsal head and the sesamoid bones. The joint space normally appears uniform on x-ray. Narrowing and unevenness indicate pathology.
If it is difficult to judge the presence of a sesamoid fracture from a plain X-ray, a scan may be ordered. This is a test in which a special solution, a contrast agent, is injected intravenously. The contrast agent accumulates in bone tissue in a certain way. By scanning the human skeleton with X-rays, special images are created that reflect the accumulated X-ray contrast agent. If there is a pathological focus in the bone tissue, then the pattern of accumulation of the contrast agent will look different. Each pathological process has its own unique pattern of contrast agent accumulation. In this way, a fracture can be distinguished from a congenital separation of the sesamoid bone.
To obtain the most complete picture of the disease, magnetic resonance imaging (MRI) may be necessary. Using MR images, you can study the relationships between the anatomical structures of the foot and exclude others. pathological processes, including infection.
Treatment
Conservative treatment
As a rule, treatment begins with conservative methods. Typically, in this case, nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, indomethacin, and ibuprofen, are recommended. These remedies usually relieve pain and inflammation well. You can try using special insoles that ease the load on the first metatarsophalangeal joint. Be sure to avoid using high-heeled shoes. The higher the heel, the greater the load on the forefoot, and therefore on the painful metatarsophalangeal joint. In some cases, your doctor may suggest an injection steroid drug into the painful area. This usually helps relieve severe pain.
If there is a sesamoid fracture without a rupture of the extensor apparatus, wearing a plaster or plastic splint for approximately six weeks is recommended. After this, the patient must wear hard-soled shoes. The rigid sole holds the toe in a straight position, preventing the foot from rolling - thus relieving the load on the flexion apparatus. In some cases, the doctor may recommend treatment without the use of splints, prescribing the wearing of shoes with hard soles. If a fracture of the sesamoid bone occurs with a rupture of the flexor apparatus, then for full recovery functions require surgical treatment.
Stress fractures and aseptic necrosis sesamoid bones are less amenable to conservative treatment. Some doctors recommend a plaster or plastic splint for up to eight weeks without putting any weight on the leg. If, after prescribing conservative treatment, it does not get better within 8 to 12 weeks, then surgery is most likely necessary.
Surgical treatment
Sesamoid bone removal
Your doctor may suggest removing part or all of the sesamoid bone. When the sesamoid bone is partially removed, the other sesamoid bone is able to provide a fulcrum for the flexors. However, if both bones are removed, the flexors will not be able to function normally and the first toe will become claw-shaped. Therefore, surgeons usually avoid removing both sesamoid bones.
When the sesamoid bone is fractured, surgery is performed to remove non-functional fragments and restore the integrity of the flexor apparatus. For stress fractures in athletes, when the most complete recovery is needed, surgery can be performed using bone grafts. To remove the sesamoid bones, an incision is made on the inside of the foot. Sometimes it becomes necessary to perform this operation from an incision along the plantar side of the foot between the heads of the first and second metatarsal bones.
Rehabilitation
Rehabilitation after conservative treatment
If the pain syndrome is mild, the doctor may allow you to continue your daily activities immediately, but with the condition that you use shoes with hard soles. If the disease is moderate, you will need to use crutches and not put any weight on your leg for a period of several days to two to three weeks. If the pain is severe, you will need to walk on crutches without putting any weight on your leg for several weeks. Typically, full recovery should not be expected until four to six weeks.
Physical therapy can help reduce pain and swelling. If there are no contraindications, then ultrasound is prescribed, thermal procedures. Sometimes the use of anti-inflammatory ointments and creams is combined with physiotherapy.
Rehabilitation after surgical treatment
After surgical treatment Most patients are advised to use crutches and avoid putting weight on the leg. For those who have undergone restoration of the flexor apparatus of the first toe or bone grafting, immobilization with a plaster or plastic splint is recommended. After this, it is recommended to wear shoes with hard soles until complete recovery. The results of bone grafting of the sesamoid bone can be assessed after 2 months by performing an MRI.
Physical therapy exercises are required. Depending on the operation performed, exercises begin at different terms after surgery, gradually increasing the load and complexity. Physiotherapy necessary to restore and maintain muscle tone of the lower leg and foot.
