The Foot and Ankle
Content
THE FOOT / ANKLE
BONES – LIGAMANETS – TENDONS – MUSCLE – ARTERIES – STRUCTURE – MOVEMENT – FACETS – SCHEMATIC – SUPPORT OF ARCH – FOOTPRINTS – NERVE THAT IMPACT ON FOOT / ANKLE FUNCTION
Bones of the foot
The synovial tendon sheaths of the foot and ankle.
The more distal and somewhat less constant sheaths of the extensor digitorum longus and brevis have been omitted
Muscles of the sole of the foot, shown in successive layers from inferior to superior. A, The first, or most superficial, layer. B, The second layer. C, The third layer, including the peroneus longus, the insertion of which belongs to the fourth layer.
The arteries of the sole and dorsum of the foot.
The structures on (A) the medial, (B) the lateral, and (C) the anterior portions of the ankle. The various retinacula are shown. The posterior tibial artery is situated (in A) between the medial malleolus and the calcaneal tendon. The dorsal artery of the foot is found (in C) between the digitorum and hallucis tendons. The pulsations of these arteries are sought in clinical examinations of the lower limb.
The ligaments of the ankle joint.
The medial view shows the medial ligament, which forms a dense, almost continuous deltoid ligament.
The ligaments on the lateral side, however, are usually separated from one another. Note the sinus tarsi in the lateral view
Movements of the foot and ankle. Dorsiflexion and plantar flexion; are shown as in walking up and down hill. Movement occurs at the ankle joint. Eversion and inversion; are shown as in standing sideways on a hill. Movement occurs at the tarsal joints, the talus remaining fixed.
The facets of the ankle subtalar, and talocalcaneonavicular joints.
A, Diagram of the talus from above to show the three-surfaced trochlea that fits into the mortise formed by the lower ends of the tibia and fibula. B, Diagram of the calcaneus from above to show the posterior facet (P) for the subtalar joint, separated by the canalis and sinus tarsi from the middle (M) and anterior (A) facets of the talocalcaneonavicular joint. The socket of this latter joint is completed by the spring ligament and the concavity of the navicular. C, Diagram of the talus from below to show its corresponding facets for the subtalar and calcaneonavicular joints. The broad arrow in A emphasizes that the head of the talus is directed anteromedially
The tendons and ligaments of the foot, plantar aspect.
Note the widespread insertion of the tibialis posterior. The fibularis longus tendon crosses the sole obliquely to reach the medial cuneiform, to which the tibialis anterior is also attached: the two muscles thus form a sling or stirrup
Schematic representation of the plantar aponeurosis and the long plantar ligament
Footprints
A, Normal. B, Flatfoot. C, High longitudinal arch
The connection between the calcaneus and the metatarsal represents schematically the ligamentous support of the arch. A, The three main points of weight bearing in the foot. B, The medial part of the longitudinal arch. The arrows indicate the distribution of weight that tends to flatten the arch.
The bony components of the longitudinal arches. The third Fig. shows both arches.
THE NERVES OF THE FOOT ARE ALL BRANCHES OF ONE OF TWO NERVES!
THE FEMORAL NERVE; which provides only a small amount of innervation (nerve supply) to the foot, and the Sciatic Nerve, which provides the vast majority of the innervation to the foot. The Femoral Nerve arises from nerve fibres from the L2-L3-L4 portion of the lumbar spine. This means that the nerves leave the spinal cord beneath the 2nd, 3rd and 4th Lumbar vertebrae. The Femoral Nerve then passes down the inside edge of the thigh, past the inside of the knee and towards the ankle and foot.
OR THE SCIATIC NERVE; which is the largest nerve in the body and it is comprised of nerves from the L4-L5-S1S2-S3 level of the spine. (This means that the nerve fibres that make up the Sciatic Nerve leave the spinal cord beneath the fourth and fifth lumbar and the first, second and third sacral vertebrae.) It then descends down the back of the thigh.
THE SCIATIC NERVE
THE SCIATIC NERVE; is the largest nerve in the body and it is comprised of nerves from the L4-L5-S1-S2-S3 level of the spine. This means that the nerve fibres that make up the Sciatic Nerve leave the spinal cord beneath the fourth and fifth lumbar and the first, second and third sacral vertebrae. It then descends down the back of the thigh, and near the bottom third of the thigh branching into two nerves, The Common Peroneal Nerve, comprised of nerve fibers from L5, S1, S2, and S3, and The Tibial Nerve comprised of nerve fibres from L4, L5, S1, S2 and S3) Each of these nerves then continues down the leg towards the knee joint. Shortly after crossing the knee joint, the Common Peroneal Nerve divides into three branches; the Lateral Sural Cutaneous Nerve, the Deep Peroneal Nerve and the Superficial Peroneal Nerve. THE LATERAL SURAL CUTANEOUS NERVE; merges with the Medial Sural Cutaneous Nerve (a branch from the Tibial Nerve described below) to form the Sural Nerve. The Sural Nerve then runs down the outside edge of the leg. THE DEEP PERONEAL NERVE; begins at the outside edge of the upper leg, then moves across the tibia bone in the leg to supply nerve function to the muscles on the front of the leg (the Tibialis Anterior, Extensor Hallucis Longus, Extensor Digitorum Longus and Peroneus Tertius muscles). The Deep Peroneal Nerve then continues down the leg towards the foot. THE SUPERFICIAL NERVE; supplies nervous function to the Peroneus Longus and Peroneus Brevis muscles, then continues down the leg. It eventually branches into two nerves, the Medial Dorsal Cutaneous Nerve and the Intermediate Dorsal Cutaneous Nerves. The first branch off the Tibial Nerve is the Medial Sural Cutaneous Nerve, (mentioned above), it connects with the Lateral Sural Cutaneous Nerve (a branch of the Common Peroneal Nerve) to form the Sural Nerve. The Tibial Nerve then supplies the nervous function to the muscles in the back of the leg - the Popliteus, Gastrocnemius, Soleus, Plantaris, Tibialis Posterior, Flexor Digitorum Longus and Flexor Hallucis Longus muscles. The Tibial Nerve then continues down the back of the leg towards the ankle and foot.
THERE ARE FIVE MAJOR NERVES HEADING FROM THE LEG THAT IMPACT ON THE ANKLE / FOOT!
1. THE SURAL NERVE; which crosses behind the lateral malleolus (the bump on the outside portion of the ankle). Once in the foot, the Sural Nerve's name changes to the Lateral Dorsal Cutaneous Nerve, and it supplies the sensory information back to the brain concerning the outside edge of the foot, including the small toe. 2. THE SAPHENOUS NERVE; which crosses behind the medial malleolus (the bump on the inside portion of the ankle). This nerve retains its name and supplies the sensory information back to the brain concerning the inside edge of the foot including the small toe. 3. THE TIBIAL NERVE; which crosses the ankle behind the medial malleolus (the bump on the inside portion of the ankle) has three nerve branches; the Medial Calcaneal, Medial Plantar / Lateral Plantar. 3.1. The Medial Calcaneal Nerve; which is the smallest branch which runs along the medial (inside) portion of the heel, and provides the sensory innervation for that portion of the heel. 3.2. The Medial Plantar Nerve; which is the larger of the two major nerves on the bottom of the foot. The fibres that make up this nerve originate at the S2-S3 level. The Medial Plantar Nerve gives sensory perception to the bottom of the big toe, the second and third toes and half of the fourth toe, as well as the medial (inside) 2/3's of the bottom of the foot. This nerve provides innervation (nerve connection) with the Flexor Digitorum Brevis (FDB), Flexor Hallucis Brevis (FHB), Adductor Hallucis, and 1st Lumbrical muscles. 3.3. The Lateral Plantar Nerve; which is the smaller of the two nerves on the bottom of the foot. (See diagram to the right.) As with the Medial Plantar Nerve, The fibres that make up the Lateral Plantar Nerve left the spine at the S2-S3 level. The Lateral Plantar Nerves provides sensory perception to the the outside 1/3 of the bottom of the foot, including the fifth toe and half of the fourth toe. It innervates the Quadratus Plantae, Abductor Digiti Quinti, Flexor Digiti Quinti Brevis, 1st, 2nd, 3rd and 4th Dorsal Interossei, the 1st, 2nd and 3rd Plantar Interossei and the 2nd, 3rd and 4th Lumbrical muscles. We should probably mention here that a branch from the medial plantar nerve with a branch from the lateral plantar nerve join together in the fourth inter-space of the foot, and this is the primary location for a neuroma to develop. 4. THE DEEP PERONEAL NERVE also known as the ANTERIOR TIBIAL NERVE; passes on the front of the ankle. It divides into the medial and lateral branches. The medial branch advances down the foot and supplies nervous sensation to the space between the big toe and second toe. The lateral branch supplies the nervous input to the Extensor Digitorum Brevis muscle, then divides into three branches which supply the nervous input to the 2nd, 3rd and 4th Interosseous muscles 5. SUPERFICIAL PERONEAL NERVE.
BONES – LIGAMANETS – TENDONS – MUSCLE – ARTERIES – STRUCTURE – MOVEMENT – FACETS – SCHEMATIC – SUPPORT OF ARCH – FOOTPRINTS – NERVE THAT IMPACT ON FOOT / ANKLE FUNCTION
Bones of the foot
The synovial tendon sheaths of the foot and ankle.
The more distal and somewhat less constant sheaths of the extensor digitorum longus and brevis have been omitted
Muscles of the sole of the foot, shown in successive layers from inferior to superior. A, The first, or most superficial, layer. B, The second layer. C, The third layer, including the peroneus longus, the insertion of which belongs to the fourth layer.
The arteries of the sole and dorsum of the foot.
The structures on (A) the medial, (B) the lateral, and (C) the anterior portions of the ankle. The various retinacula are shown. The posterior tibial artery is situated (in A) between the medial malleolus and the calcaneal tendon. The dorsal artery of the foot is found (in C) between the digitorum and hallucis tendons. The pulsations of these arteries are sought in clinical examinations of the lower limb.
The ligaments of the ankle joint.
The medial view shows the medial ligament, which forms a dense, almost continuous deltoid ligament.
The ligaments on the lateral side, however, are usually separated from one another. Note the sinus tarsi in the lateral view
Movements of the foot and ankle. Dorsiflexion and plantar flexion; are shown as in walking up and down hill. Movement occurs at the ankle joint. Eversion and inversion; are shown as in standing sideways on a hill. Movement occurs at the tarsal joints, the talus remaining fixed.
The facets of the ankle subtalar, and talocalcaneonavicular joints.
A, Diagram of the talus from above to show the three-surfaced trochlea that fits into the mortise formed by the lower ends of the tibia and fibula. B, Diagram of the calcaneus from above to show the posterior facet (P) for the subtalar joint, separated by the canalis and sinus tarsi from the middle (M) and anterior (A) facets of the talocalcaneonavicular joint. The socket of this latter joint is completed by the spring ligament and the concavity of the navicular. C, Diagram of the talus from below to show its corresponding facets for the subtalar and calcaneonavicular joints. The broad arrow in A emphasizes that the head of the talus is directed anteromedially
The tendons and ligaments of the foot, plantar aspect.
Note the widespread insertion of the tibialis posterior. The fibularis longus tendon crosses the sole obliquely to reach the medial cuneiform, to which the tibialis anterior is also attached: the two muscles thus form a sling or stirrup
Schematic representation of the plantar aponeurosis and the long plantar ligament
Footprints
A, Normal. B, Flatfoot. C, High longitudinal arch
The connection between the calcaneus and the metatarsal represents schematically the ligamentous support of the arch. A, The three main points of weight bearing in the foot. B, The medial part of the longitudinal arch. The arrows indicate the distribution of weight that tends to flatten the arch.
The bony components of the longitudinal arches. The third Fig. shows both arches.
THE NERVES OF THE FOOT ARE ALL BRANCHES OF ONE OF TWO NERVES!
THE FEMORAL NERVE; which provides only a small amount of innervation (nerve supply) to the foot, and the Sciatic Nerve, which provides the vast majority of the innervation to the foot. The Femoral Nerve arises from nerve fibres from the L2-L3-L4 portion of the lumbar spine. This means that the nerves leave the spinal cord beneath the 2nd, 3rd and 4th Lumbar vertebrae. The Femoral Nerve then passes down the inside edge of the thigh, past the inside of the knee and towards the ankle and foot.
OR THE SCIATIC NERVE; which is the largest nerve in the body and it is comprised of nerves from the L4-L5-S1S2-S3 level of the spine. (This means that the nerve fibres that make up the Sciatic Nerve leave the spinal cord beneath the fourth and fifth lumbar and the first, second and third sacral vertebrae.) It then descends down the back of the thigh.
THE SCIATIC NERVE
THE SCIATIC NERVE; is the largest nerve in the body and it is comprised of nerves from the L4-L5-S1-S2-S3 level of the spine. This means that the nerve fibres that make up the Sciatic Nerve leave the spinal cord beneath the fourth and fifth lumbar and the first, second and third sacral vertebrae. It then descends down the back of the thigh, and near the bottom third of the thigh branching into two nerves, The Common Peroneal Nerve, comprised of nerve fibers from L5, S1, S2, and S3, and The Tibial Nerve comprised of nerve fibres from L4, L5, S1, S2 and S3) Each of these nerves then continues down the leg towards the knee joint. Shortly after crossing the knee joint, the Common Peroneal Nerve divides into three branches; the Lateral Sural Cutaneous Nerve, the Deep Peroneal Nerve and the Superficial Peroneal Nerve. THE LATERAL SURAL CUTANEOUS NERVE; merges with the Medial Sural Cutaneous Nerve (a branch from the Tibial Nerve described below) to form the Sural Nerve. The Sural Nerve then runs down the outside edge of the leg. THE DEEP PERONEAL NERVE; begins at the outside edge of the upper leg, then moves across the tibia bone in the leg to supply nerve function to the muscles on the front of the leg (the Tibialis Anterior, Extensor Hallucis Longus, Extensor Digitorum Longus and Peroneus Tertius muscles). The Deep Peroneal Nerve then continues down the leg towards the foot. THE SUPERFICIAL NERVE; supplies nervous function to the Peroneus Longus and Peroneus Brevis muscles, then continues down the leg. It eventually branches into two nerves, the Medial Dorsal Cutaneous Nerve and the Intermediate Dorsal Cutaneous Nerves. The first branch off the Tibial Nerve is the Medial Sural Cutaneous Nerve, (mentioned above), it connects with the Lateral Sural Cutaneous Nerve (a branch of the Common Peroneal Nerve) to form the Sural Nerve. The Tibial Nerve then supplies the nervous function to the muscles in the back of the leg - the Popliteus, Gastrocnemius, Soleus, Plantaris, Tibialis Posterior, Flexor Digitorum Longus and Flexor Hallucis Longus muscles. The Tibial Nerve then continues down the back of the leg towards the ankle and foot.
THERE ARE FIVE MAJOR NERVES HEADING FROM THE LEG THAT IMPACT ON THE ANKLE / FOOT!
1. THE SURAL NERVE; which crosses behind the lateral malleolus (the bump on the outside portion of the ankle). Once in the foot, the Sural Nerve's name changes to the Lateral Dorsal Cutaneous Nerve, and it supplies the sensory information back to the brain concerning the outside edge of the foot, including the small toe. 2. THE SAPHENOUS NERVE; which crosses behind the medial malleolus (the bump on the inside portion of the ankle). This nerve retains its name and supplies the sensory information back to the brain concerning the inside edge of the foot including the small toe. 3. THE TIBIAL NERVE; which crosses the ankle behind the medial malleolus (the bump on the inside portion of the ankle) has three nerve branches; the Medial Calcaneal, Medial Plantar / Lateral Plantar. 3.1. The Medial Calcaneal Nerve; which is the smallest branch which runs along the medial (inside) portion of the heel, and provides the sensory innervation for that portion of the heel. 3.2. The Medial Plantar Nerve; which is the larger of the two major nerves on the bottom of the foot. The fibres that make up this nerve originate at the S2-S3 level. The Medial Plantar Nerve gives sensory perception to the bottom of the big toe, the second and third toes and half of the fourth toe, as well as the medial (inside) 2/3's of the bottom of the foot. This nerve provides innervation (nerve connection) with the Flexor Digitorum Brevis (FDB), Flexor Hallucis Brevis (FHB), Adductor Hallucis, and 1st Lumbrical muscles. 3.3. The Lateral Plantar Nerve; which is the smaller of the two nerves on the bottom of the foot. (See diagram to the right.) As with the Medial Plantar Nerve, The fibres that make up the Lateral Plantar Nerve left the spine at the S2-S3 level. The Lateral Plantar Nerves provides sensory perception to the the outside 1/3 of the bottom of the foot, including the fifth toe and half of the fourth toe. It innervates the Quadratus Plantae, Abductor Digiti Quinti, Flexor Digiti Quinti Brevis, 1st, 2nd, 3rd and 4th Dorsal Interossei, the 1st, 2nd and 3rd Plantar Interossei and the 2nd, 3rd and 4th Lumbrical muscles. We should probably mention here that a branch from the medial plantar nerve with a branch from the lateral plantar nerve join together in the fourth inter-space of the foot, and this is the primary location for a neuroma to develop. 4. THE DEEP PERONEAL NERVE also known as the ANTERIOR TIBIAL NERVE; passes on the front of the ankle. It divides into the medial and lateral branches. The medial branch advances down the foot and supplies nervous sensation to the space between the big toe and second toe. The lateral branch supplies the nervous input to the Extensor Digitorum Brevis muscle, then divides into three branches which supply the nervous input to the 2nd, 3rd and 4th Interosseous muscles 5. SUPERFICIAL PERONEAL NERVE.
