AN19.1-7 | Back of Leg & Sole — Glossary

This is a complete rupture of the calcaneal (Achilles) tendon — one of the most important clinical presentations in lower limb anatomy.

- Plantar fasciitis is the most common cause of heel pain in adults — seen daily in primary care, especially in policemen, farmers, teachers, and nurses who stand for prolonged periods in India - Calcaneal tendon ruptures are surgical emergencies common in recreational athletes.

- Calcaneal tendon ruptures are surgical emergencies common in recreational athletes aged 30-50 - Flat foot and club foot affect millions in India — flat foot is frequently seen in army/police medical examinations as a cause of rejection - Calf muscle pump failure causes.

- Flat foot and club foot affect millions in India — flat foot is frequently seen in army/police medical examinations as a cause of rejection - Calf muscle pump failure causes varicose veins and deep vein thrombosis — a major post-surgical and obstetric complication - Surface.

- Calf muscle pump failure causes varicose veins and deep vein thrombosis — a major post-surgical and obstetric complication - Surface anatomy of the tibial nerve and posterior tibial artery are tested in every clinical examination

- Compartments of the leg: The leg has anterior, lateral, and posterior compartments.

- Popliteal fossa: The tibial nerve and popliteal artery exit the popliteal fossa to enter the posterior leg - Bones: Tibia, fibula, calcaneus (heel bone), talus (ankle bone) — you've seen these in the osteology sessions - Nerve supply pattern: Most posterior leg muscles are.

- Bones: Tibia, fibula, calcaneus (heel bone), talus (ankle bone) — you've seen these in the osteology sessions - Nerve supply pattern: Most posterior leg muscles are supplied by the tibial nerve (L4, L5, S1, S2) — the tibial nerve is the larger terminal branch of the sciatic.

- Nerve supply pattern: Most posterior leg muscles are supplied by the tibial nerve (L4, L5, S1, S2) — the tibial nerve is the larger terminal branch of the sciatic nerve - Basic muscle action: Plantarflexion = pointing the foot down (like pressing the accelerator); Dorsiflexion.

- Popliteal fossa: The tibial nerve and popliteal artery exit the popliteal fossa to enter the posterior leg - Bones: Tibia, fibula, calcaneus (heel bone), talus (ankle bone) — you've seen these in the osteology sessions - Nerve supply pattern: Most posterior leg muscles are.

- Basic muscle action: Plantarflexion = pointing the foot down (like pressing the accelerator); Dorsiflexion = pulling the foot up

The superficial posterior compartment contains three muscles that share a common insertion via the calcaneal tendon (Achilles tendon) — the thickest and strongest tendon in the body.

Gastrocnemius - Origin: Two heads from the medial and lateral femoral condyles (above the knee joint) - Insertion: Via calcaneal tendon into the posterior surface of calcaneus - Nerve supply: Tibial nerve (S1, S2) - Action: Plantarflexion of ankle + flexion of knee.

- Origin: Two heads from the medial and lateral femoral condyles (above the knee joint) - Insertion: Via calcaneal tendon into the posterior surface of calcaneus - Nerve supply: Tibial nerve (S1, S2) - Action: Plantarflexion of ankle + flexion of knee.

- Insertion: Via calcaneal tendon into the posterior surface of calcaneus - Nerve supply: Tibial nerve (S1, S2) - Action: Plantarflexion of ankle + flexion of knee.

- Nerve supply: Tibial nerve (S1, S2) - Action: Plantarflexion of ankle + flexion of knee.

- Action: Plantarflexion of ankle + flexion of knee.

Soleus - Origin: Soleal line on posterior tibia, upper fibula, fibrous arch between them - Insertion: Via calcaneal tendon (deep to gastrocnemius) - Nerve supply: Tibial nerve (S1, S2) - Action: Plantarflexion only (single-joint muscle — does NOT flex the knee).

- Clinical note: Soleus contains large venous sinuses — a common site for deep vein thrombosis (DVT) Plantaris - Small, rudimentary muscle with a long thin tendon - Origin: Lateral supracondylar line of femur - Insertion: Medial side of calcaneal tendon or separately into.

- Clinical note: Soleus contains large venous sinuses — a common site for deep vein thrombosis (DVT) Plantaris - Small, rudimentary muscle with a long thin tendon - Origin: Lateral supracondylar line of femur - Insertion: Medial side of calcaneal tendon or separately into.

Plantaris - Small, rudimentary muscle with a long thin tendon - Origin: Lateral supracondylar line of femur - Insertion: Medial side of calcaneal tendon or separately into calcaneus - Action: Weak plantarflexion.

Clinically: its tendon is used for tendon grafting in reconstructive surgery - Absent in ~7% of people The Calcaneal Tendon (Achilles Tendon) - Formed by gastrocnemius + soleus tendons, joined by plantaris - The avascular zone lies 2–6 cm above the calcaneal insertion — this is.

The Calcaneal Tendon (Achilles Tendon) - Formed by gastrocnemius + soleus tendons, joined by plantaris - The avascular zone lies 2–6 cm above the calcaneal insertion — this is where most ruptures occur - A bursa (retrocalcaneal bursa) lies between the tendon and calcaneus

- The avascular zone lies 2–6 cm above the calcaneal insertion — this is where most ruptures occur - A bursa (retrocalcaneal bursa) lies between the tendon and calcaneus

- A bursa (retrocalcaneal bursa) lies between the tendon and calcaneus

Three pass posterior to the medial malleolus in a consistent order remembered as 'Tom, Dick, ANd Very Nervous Harry': Popliteus - Origin: Lateral surface of lateral femoral condyle - Insertion: Posterior surface of tibia above the soleal line - Nerve: Tibial nerve (L4, L5,.

Popliteus - Origin: Lateral surface of lateral femoral condyle - Insertion: Posterior surface of tibia above the soleal line - Nerve: Tibial nerve (L4, L5, S1) - Action: 'Unlocks' the knee — internally rotates the tibia on the femur to begin knee flexion from the fully extended.

- Nerve: Tibial nerve (L4, L5, S1) - Action: 'Unlocks' the knee — internally rotates the tibia on the femur to begin knee flexion from the fully extended (locked) position.

Tom = Tibialis Posterior - Origin: Posterior surfaces of tibia and fibula, interosseous membrane - Insertion: Tuberosity of navicular + plantar surfaces of cuneiforms and metatarsal bases 2-4 - Action: Plantarflexion + inversion (most important invertor of the foot) - Clinical:.

- Action: Plantarflexion + inversion (most important invertor of the foot) - Clinical: Tibialis posterior tendon dysfunction → flat foot in adults Dick = Flexor Digitorum Longus (FDL) - Origin: Posterior tibia - Insertion: Bases of distal phalanges of lateral four toes -.

- Clinical: Tibialis posterior tendon dysfunction → flat foot in adults Dick = Flexor Digitorum Longus (FDL) - Origin: Posterior tibia - Insertion: Bases of distal phalanges of lateral four toes - Action: Flexes toes + assists plantarflexion.

Dick = Flexor Digitorum Longus (FDL) - Origin: Posterior tibia - Insertion: Bases of distal phalanges of lateral four toes - Action: Flexes toes + assists plantarflexion.

And = (Nothing — the 'And' is the mnemonic filler) Very Nervous = Vessels and Nerve (tibial nerve + posterior tibial artery) - These pass behind the medial malleolus in the tarsal tunnel Harry = Flexor Hallucis Longus (FHL) - Origin: Lower two-thirds of posterior fibula -.

Harry = Flexor Hallucis Longus (FHL) - Origin: Lower two-thirds of posterior fibula - Insertion: Base of distal phalanx of great toe - Action: Flexes great toe + assists plantarflexion.

- Passes posterior to the medial malleolus in the tarsal tunnel (flexor retinaculum) - Divides into medial plantar nerve and lateral plantar nerve in the sole - Motor: All muscles of the posterior leg + all intrinsic foot muscles (via plantar branches) - Sensory: Posterior leg.

- Divides into medial plantar nerve and lateral plantar nerve in the sole - Motor: All muscles of the posterior leg + all intrinsic foot muscles (via plantar branches) - Sensory: Posterior leg (sural nerve branch), sole of foot - Clinical: Tibial nerve compression in the tarsal.

- Divides into medial plantar nerve and lateral plantar nerve in the sole - Motor: All muscles of the posterior leg + all intrinsic foot muscles (via plantar branches) - Sensory: Posterior leg (sural nerve branch), sole of foot - Clinical: Tibial nerve compression in the tarsal.

- Motor: All muscles of the posterior leg + all intrinsic foot muscles (via plantar branches) - Sensory: Posterior leg (sural nerve branch), sole of foot - Clinical: Tibial nerve compression in the tarsal tunnel → tarsal tunnel syndrome (tingling/numbness in sole + weakness of.

- Sensory: Posterior leg (sural nerve branch), sole of foot - Clinical: Tibial nerve compression in the tarsal tunnel → tarsal tunnel syndrome (tingling/numbness in sole + weakness of intrinsic foot muscles) Posterior Tibial Artery (larger terminal branch of popliteal artery) -.

- Clinical: Tibial nerve compression in the tarsal tunnel → tarsal tunnel syndrome (tingling/numbness in sole + weakness of intrinsic foot muscles) Posterior Tibial Artery (larger terminal branch of popliteal artery) - Accompanies the tibial nerve throughout - Peroneal.

Posterior Tibial Artery (larger terminal branch of popliteal artery) - Accompanies the tibial nerve throughout - Peroneal (fibular) artery is its largest branch — supplies lateral compartment and fibula - At the tarsal tunnel: divides into medial and lateral plantar arteries -.

- Peroneal (fibular) artery is its largest branch — supplies lateral compartment and fibula - At the tarsal tunnel: divides into medial and lateral plantar arteries - Clinical pulse point: Palpable posterior to medial malleolus — used to assess peripheral vascular disease (PVD).

- Passes posterior to the medial malleolus in the tarsal tunnel (flexor retinaculum) - Divides into medial plantar nerve and lateral plantar nerve in the sole - Motor: All muscles of the posterior leg + all intrinsic foot muscles (via plantar branches) - Sensory: Posterior leg.

- At the tarsal tunnel: divides into medial and lateral plantar arteries - Clinical pulse point: Palpable posterior to medial malleolus — used to assess peripheral vascular disease (PVD) and diabetes-related ischaemia - Absent or poorly palpable in ~10% of normal individuals

- Clinical pulse point: Palpable posterior to medial malleolus — used to assess peripheral vascular disease (PVD) and diabetes-related ischaemia - Absent or poorly palpable in ~10% of normal individuals

The Thompson (Simmonds) test is the definitive bedside test for calcaneal tendon rupture: Method: Patient lies prone on examination table.

Method: Patient lies prone on examination table.

Normal: foot plantarflexes (tendon intact).

Rupture: no movement of foot.

Why it works: Squeezing the calf compresses gastrocnemius and soleus.

Anatomy of rupture site: The avascular zone 2-6 cm above the calcaneal insertion has the poorest blood supply.

Management note: Ruptures in patients <40 years who are active → surgical repair.

The 'peripheral heart' is the calf muscle pump mechanism — the most important venous return mechanism in the lower limb (AN19.3).

Anatomy of the mechanism: 1.

When calf muscles contract (e.g., during walking), they compress the deep veins, pumping blood proximally toward the heart 3.

Venous valves in these deep veins prevent backflow during muscle relaxation 4.

Why 'peripheral heart'?: The calf muscles functionally substitute for cardiac pumping action in the lower limb.

Clinical consequences of pump failure: - Varicose veins: Valve incompetence → superficial vein dilatation - Deep vein thrombosis (DVT): Prolonged immobility (long flights, post-surgery, bed rest) → stasis in soleal sinuses → thrombus formation - Post-thrombotic syndrome: Chronic.

- Varicose veins: Valve incompetence → superficial vein dilatation - Deep vein thrombosis (DVT): Prolonged immobility (long flights, post-surgery, bed rest) → stasis in soleal sinuses → thrombus formation - Post-thrombotic syndrome: Chronic venous hypertension → leg ulcers -.

- Post-thrombotic syndrome: Chronic venous hypertension → leg ulcers - Thromboembolism: DVT fragments travel to pulmonary vasculature → pulmonary embolism (PE) Indian context: DVT is commonly encountered post-caesarean section, post-orthopaedic surgery (hip and knee.

- Thromboembolism: DVT fragments travel to pulmonary vasculature → pulmonary embolism (PE) Indian context: DVT is commonly encountered post-caesarean section, post-orthopaedic surgery (hip and knee replacement), and after long-haul bus/train journeys.

Indian context: DVT is commonly encountered post-caesarean section, post-orthopaedic surgery (hip and knee replacement), and after long-haul bus/train journeys.

The foot has three arches that distribute body weight and absorb shock: Medial Longitudinal Arch (MLA) - Highest and most important arch - Bones: calcaneus → talus → navicular → 3 cuneiforms → metatarsals 1-3 - Keystone: talus (receives body weight from tibia) - Maintained by:.

Medial Longitudinal Arch (MLA) - Highest and most important arch - Bones: calcaneus → talus → navicular → 3 cuneiforms → metatarsals 1-3 - Keystone: talus (receives body weight from tibia) - Maintained by: Spring ligament (plantar calcaneonavicular ligament) — primary static.

- Bones: calcaneus → talus → navicular → 3 cuneiforms → metatarsals 1-3 - Keystone: talus (receives body weight from tibia) - Maintained by: Spring ligament (plantar calcaneonavicular ligament) — primary static support; Tibialis posterior tendon — dynamic support; Flexor.

Lateral Longitudinal Arch (LLA) - Lower, less mobile, bears weight more directly - Bones: calcaneus → cuboid → metatarsals 4-5 - Maintained by: Long and short plantar ligaments Transverse Arch - Runs across the foot at the level of the metatarsal heads - Maintained by: Peroneus.

Transverse Arch - Runs across the foot at the level of the metatarsal heads - Maintained by: Peroneus longus (passes under cuboid to base of 1st metatarsal — ties the arch together); Deep transverse metatarsal ligaments Importance of arches: - Distribute weight between heel and.

Importance of arches: - Distribute weight between heel and ball of foot - Act as shock absorbers during walking and running - Store and release elastic energy (spring-like action) - Failure → flat foot or plantar fasciitis

The sole has four layers of intrinsic muscles: - Layer 1 (superficial): Abductor hallucis, Flexor digitorum brevis, Abductor digiti minimi - Layer 2: Quadratus plantae (+ FDL tendons), Lumbricals - Layer 3: Flexor hallucis brevis, Adductor hallucis, Flexor digiti minimi brevis -.

- Layer 1 (superficial): Abductor hallucis, Flexor digitorum brevis, Abductor digiti minimi - Layer 2: Quadratus plantae (+ FDL tendons), Lumbricals - Layer 3: Flexor hallucis brevis, Adductor hallucis, Flexor digiti minimi brevis - Layer 4 (deep): Plantar and dorsal.

- Layer 2: Quadratus plantae (+ FDL tendons), Lumbricals - Layer 3: Flexor hallucis brevis, Adductor hallucis, Flexor digiti minimi brevis - Layer 4 (deep): Plantar and dorsal interossei Medial Plantar Nerve (larger branch of tibial nerve) - Analogous to the median nerve in the.

- Layer 3: Flexor hallucis brevis, Adductor hallucis, Flexor digiti minimi brevis - Layer 4 (deep): Plantar and dorsal interossei Medial Plantar Nerve (larger branch of tibial nerve) - Analogous to the median nerve in the hand - Supplies: Flexor digitorum brevis, Abductor.

- Layer 4 (deep): Plantar and dorsal interossei Medial Plantar Nerve (larger branch of tibial nerve) - Analogous to the median nerve in the hand - Supplies: Flexor digitorum brevis, Abductor hallucis, Flexor hallucis brevis, 1st lumbrical - Sensation: Medial 3½ toes and.

Memory aid: 'LAFF' — Lumbricals 1, Abductor hallucis, Flexor digitorum brevis, Flexor hallucis brevis → Medial plantar nerve

Flat Foot (Pes Planus) — AN19.6 Definition: Loss of the medial longitudinal arch Types: - Flexible flat foot: Arch present on non-weight-bearing, disappears on standing.

Definition: Loss of the medial longitudinal arch Types: - Flexible flat foot: Arch present on non-weight-bearing, disappears on standing.

Types: - Flexible flat foot: Arch present on non-weight-bearing, disappears on standing.

- Flexible flat foot: Arch present on non-weight-bearing, disappears on standing.

- Rigid flat foot: Arch absent even on non-weight-bearing.

Anatomical basis: Failure of spring ligament (plantar calcaneonavicular ligament) + tibialis posterior dysfunction → medial longitudinal arch collapses → calcaneus everts (valgus), forefoot abducts, talus plantarflexes Indian context: Commonly flagged in Army/Police/Railway.

Signs: Medial border of foot touches ground, 'too many toes sign' (seeing >2 toes lateral to heel from behind), loss of heel inversion on standing on tiptoe --- Club Foot (Talipes Equinovarus) — AN19.

Club Foot (Talipes Equinovarus) — AN19.6 Definition: The most common congenital foot deformity (1-2 per 1000 births in India) Four deformities (remember 'CAVE'): - Cavus — raised medial arch - Adductus — forefoot adducted - Varus — heel inverted (varus) - Equinus — foot.

Four deformities (remember 'CAVE'): - Cavus — raised medial arch - Adductus — forefoot adducted - Varus — heel inverted (varus) - Equinus — foot plantarflexed (heel up) Anatomical basis: Shortened intrinsic foot muscles, contracted plantar fascia, medial ligaments, and.

Treatment: Ponseti method (serial casting from birth) — corrects all deformities by 6-8 weeks; last percutaneous Achilles tenotomy corrects the equinus.

Treatment: Ponseti method (serial casting from birth) — corrects all deformities by 6-8 weeks; last percutaneous Achilles tenotomy corrects the equinus.

Anatomy: The plantar fascia (plantar aponeurosis) is a thick fibrous band from the medial tubercle of calcaneus to the flexor tendon sheaths of all five toes.

Anatomy: The plantar fascia (plantar aponeurosis) is a thick fibrous band from the medial tubercle of calcaneus to the flexor tendon sheaths of all five toes.

It maintains the medial longitudinal arch via the windlass mechanism — when toes are dorsiflexed, the plantar fascia tightens, raising the arch.

Pathology: Repetitive microtrauma at the calcaneal origin → chronic inflammatory degeneration (fasciosis) Presentation: - Severe sharp heel pain on first steps in the morning (first 15-20 steps) → eases with activity → returns after prolonged standing - Point tenderness at.

Presentation: - Severe sharp heel pain on first steps in the morning (first 15-20 steps) → eases with activity → returns after prolonged standing - Point tenderness at medial calcaneal tubercle - Worsened by standing barefoot on hard floors (extremely common in Indian.

Risk factors in Indian population: Prolonged standing (police officers, nurses, teachers, temple priests), obesity, flat foot, tight Achilles tendon, unsupportive footwear (chappals) Calcaneal spur: ~50% of plantar fasciitis cases show a bony spur on heel X-ray.

Calcaneal spur: ~50% of plantar fasciitis cases show a bony spur on heel X-ray.

Metatarsalgia — AN19.7 Definition: Pain under the metatarsal heads (ball of the foot) Anatomical basis: Loss of the transverse arch → metatarsal heads bear unequal pressure → fat pad atrophy or displacement → pain Common in: Rheumatoid arthritis (causes subluxation of.

Common in: Rheumatoid arthritis (causes subluxation of metatarsal heads), hallux valgus, prolonged wearing of high heels (transfers weight to metatarsal heads) Morton's neuroma: A specific cause of metatarsalgia — perineural fibrosis of the plantar digital nerve (usually.

Morton's neuroma: A specific cause of metatarsalgia — perineural fibrosis of the plantar digital nerve (usually 3rd-4th web space) — feels like 'walking on a pebble'

The posterior tibial nerve block is an essential clinical procedure for foot surgery, nail removal, and diabetic wound care: Landmark: The posterior tibial nerve lies immediately posterior to the posterior tibial artery pulse behind the medial malleolus.

Landmark: The posterior tibial nerve lies immediately posterior to the posterior tibial artery pulse behind the medial malleolus.

Landmark: The posterior tibial nerve lies immediately posterior to the posterior tibial artery pulse behind the medial malleolus.

Technique: Palpate the posterior tibial artery pulse posterior to the medial malleolus.

What is blocked: All intrinsic foot muscles + sensory supply to the sole (medial + lateral plantar nerves).

Why anatomy matters: Missing the nerve medially (injecting too far anterior = injecting into the tarsal tunnel tendons) → tendon damage.

Superficial posterior compartment: Gastrocnemius + Soleus + Plantaris → calcaneal tendon → plantarflexion.

Deep posterior compartment: Popliteus (unlocks knee) + Tom Dick And Harry (tibialis posterior, FDL, vessels/nerves, FHL).

Calcaneal tendon rupture: Avascular zone 2-6 cm above insertion.

Peripheral heart: Calf muscle pump compresses soleal venous sinuses → propels blood centrally against gravity.

Arches: Medial longitudinal (keystone: talus; maintained by spring ligament + tibialis posterior); lateral longitudinal; transverse (maintained by peroneus longus).

Flat foot: Flexible (common, physiological in children) vs rigid (tibialis posterior dysfunction in adults).

Club foot (CAVE): Cavus + Adductus + Varus + Equinus.

Plantar nerves: Medial (= median of hand) supplies LAFF; lateral (= ulnar of hand) supplies the rest.