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The front of the leg extends from the knee to the ankle, lying between the tibial crest medially and anterior border of fibula laterally.
It corresponds to the anterior compartment of the leg, which contains muscles responsible for dorsiflexion of the foot and extension of toes.
Skin is thin and adherent over the shin due to little subcutaneous fat; over the dorsum of foot, it is loose and mobile.
The area is supplied mainly by deep peroneal nerve and anterior tibial artery.
Common pathological involvement includes shin pain, anterior compartment syndrome, and foot drop (due to nerve lesion).
Tibial crest (shin) – prominent ridge felt from tibial tuberosity to the medial malleolus.
Tibial tuberosity – below the patella; insertion of ligamentum patellae.
Head of fibula – palpable on the lateral side just below the knee joint.
Anterior border of fibula – less distinct than tibia, can be traced distally.
Medial malleolus – subcutaneous prominence on medial side of ankle.
Lateral malleolus – slightly posterior and lower than medial malleolus.
Tendons on front of ankle (from medial to lateral):
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Peroneus tertius
Mnemonic: “Tom Has Dirty Pants” (TA, EHL, EDL, PT).
Dorsalis pedis artery – palpable lateral to the tendon of extensor hallucis longus.
Superficial veins and nerves can be seen in lean individuals under the skin, especially during extension of the toes.
Contains cutaneous veins, nerves, and lymphatics.
Anteriorly: very thin and closely adherent to skin over the shin (tibia).
Laterally and over dorsum of foot: loose, allowing free movement of skin.
No deep fat pads like in sole; this helps easy movement of tendons.
Lymphatics drain into superficial inguinal nodes medially and popliteal nodes laterally.
Great (long) saphenous vein:
Begins from the medial end of dorsal venous arch of the foot.
Ascends in front of the medial malleolus and along medial border of tibia.
Joins the femoral vein through the saphenous opening in the thigh.
Small (short) saphenous vein:
Begins from the lateral end of dorsal venous arch.
Passes behind the lateral malleolus, ascends in the posterior leg, and drains into the popliteal vein.
Dorsal venous arch:
Lies across the dorsum of the foot, forming the main communication between medial and lateral veins.
These veins have valves to prevent backflow and play a role in venous return during walking.
Saphenous nerve:
Continuation of the femoral nerve; supplies skin along the medial leg and medial side of foot up to great toe.
Superficial peroneal (musculocutaneous) nerve:
Supplies lower two-thirds of anterolateral leg and most of dorsum of foot (except first web space).
Deep peroneal nerve:
Supplies first interdigital cleft (first web space).
Sural nerve:
Supplies posterolateral side of leg and lateral border of foot.
Common peroneal nerve (upper part of leg):
Winds around neck of fibula, can be palpated superficially—vulnerable to injury.
Position: cadaver supine, leg slightly rotated medially.
Incisions:
A midline incision from tibial tuberosity to ankle joint.
Two transverse incisions across the upper and lower ends of leg.
Reflections:
Skin reflected laterally and medially to expose superficial fascia.
Identify superficial veins (great and small saphenous) and cutaneous nerves (saphenous, superficial peroneal, sural).
Trace them upward to their origins or downward to branches.
Preserve the dorsal venous arch and note its communication with saphenous veins.
The deep fascia of leg is a dense fibrous sheath that encloses the muscles.
Over the anterior surface of tibia, it is firmly attached to the subcutaneous bone, giving the skin its tight adherence.
Continuous above with the fascia lata of the thigh, and below with the deep fascia of the foot.
Gives off intermuscular septa:
Anterior intermuscular septum → separates anterior and lateral compartments.
Posterior intermuscular septum → separates lateral and posterior compartments.
Forms the interosseous membrane between tibia and fibula along with the bones, adding compartmental strength.
Thickened distally to form retinacula (bands that hold tendons close to ankle).
Functions:
Prevents bowstringing of tendons during dorsiflexion.
Maintains compartmental pressure, aiding venous return.
Provides attachments for underlying muscles.
A strong, transverse fibrous band just above the ankle joint.
Extends between:
Lower part of anterior border of fibula (laterally), and
Anterior border of tibia (medially).
Blends with the deep fascia of leg above and ankle capsule below.
Contents passing deep to it (medial → lateral):
Tibialis anterior tendon
Extensor hallucis longus tendon
Anterior tibial artery with deep peroneal nerve
Extensor digitorum longus tendon
Peroneus tertius tendon
Mnemonic: “Tom Has A Nurse Dog Pet” (TA, EHL, Artery/Nerve, EDL, PT).
Each tendon is surrounded by a synovial sheath to reduce friction.
Y-shaped band of deep fascia over the front of ankle and dorsum of foot.
Attachment:
Stem (base of Y) → attached laterally to the upper surface of calcaneum (anterior part).
Upper limb → passes medially and upward to medial malleolus.
Lower limb → passes medially and downward to blend with plantar aponeurosis and first cuneiform.
Structures passing deep to limbs of Y (medial → lateral):
Upper limb: tibialis anterior, extensor hallucis longus, anterior tibial vessels and deep peroneal nerve.
Lower limb: extensor digitorum longus and peroneus tertius.
Function → binds tendons securely during ankle movements, preventing displacement.
Continue from previous step (after exposing superficial fascia).
Carefully remove remaining fascia to demonstrate thickening of deep fascia near ankle.
Identify superior and inferior extensor retinacula as fibrous bands crossing the tendons.
Trace the tendons of tibialis anterior, extensor hallucis longus, and extensor digitorum longus under these retinacula.
Display synovial sheaths of tendons — particularly the sheath of tibialis anterior extending high up the leg.
Observe the passage of deep peroneal nerve and anterior tibial vessels between the tendons.
On dorsum of foot, identify extensor digitorum brevis deep to the tendons of EDL.
Foot Drop:
Caused by injury to deep peroneal nerve or paralysis of anterior compartment muscles.
Results in inability to dorsiflex the foot; toes drag during walking (high-stepping gait).
Compartment Syndrome (Anterior Tibial Compartment):
Tight deep fascia and septa prevent expansion of swollen muscles.
Results in pain, paresthesia, pallor, paralysis, pulselessness.
Surgical fasciotomy may be needed to relieve pressure.
Shin Splints:
Painful inflammation due to overuse or micro-trauma of tibialis anterior origin.
Common in runners and military recruits.
Tendonitis:
Friction beneath retinacula may cause inflammation of synovial sheaths (especially of EHL).
Palpation Point:
Dorsalis pedis artery can be felt lateral to tendon of EHL—absence indicates peripheral arterial disease.
Lie between tibia medially and anterior intermuscular septum laterally.
Enclosed by deep fascia and supplied by deep peroneal nerve.
Chief action → dorsiflexion of foot at ankle and extension of toes.
From medial to lateral the tendons at ankle are:
Tibialis anterior → Extensor hallucis longus → Anterior tibial artery + Deep peroneal nerve → Extensor digitorum longus → Peroneus tertius.
1. Tibialis Anterior
Origin: Upper two-thirds of lateral surface of tibia, interosseous membrane, and fascia.
Insertion: Medial cuneiform and base of 1st metatarsal.
Nerve: Deep peroneal nerve (L4, L5).
Action: Dorsiflexes ankle and inverts foot.
Clinical note: Tendon prominent in dorsiflexion; strain causes shin splints.
2. Extensor Hallucis Longus (EHL)
Origin: Middle two-fourths of anterior surface of fibula and interosseous membrane.
Insertion: Dorsum of base of distal phalanx of great toe.
Nerve: Deep peroneal nerve (L5, S1).
Action: Extends great toe, dorsiflexes foot.
Surface landmark: Tendon forms medial boundary of first web space; dorsalis pedis artery lies lateral to it.
3. Extensor Digitorum Longus (EDL)
Origin: Upper three-fourths of anterior surface of fibula, lateral condyle of tibia, interosseous membrane.
Insertion: Dorsal digital expansions of lateral four toes.
Nerve: Deep peroneal nerve (L5, S1).
Action: Extends toes and dorsiflexes foot.
Special note: Divides into 4 tendons on dorsum of foot; forms extensor expansions.
4. Peroneus (Fibularis) Tertius
Origin: Lower one-fourth of anterior fibula and interosseous membrane.
Insertion: Dorsum of base of 5th metatarsal.
Nerve: Deep peroneal nerve (L5, S1).
Action: Dorsiflexes and everts foot.
Clinical importance: Often fused partly with EDL; absent in about 10–15% of people.
Origin: From popliteal artery at lower border of popliteus.
Course:
Passes through interosseous membrane to anterior compartment.
Descends on anterior surface of membrane between tibialis anterior (medial) and EDL (lateral).
Accompanied by two venae comitantes and deep peroneal nerve (nerve crosses artery from lateral to medial near ankle).
Becomes dorsalis pedis artery in front of ankle joint midway between malleoli.
Branches:
Posterior tibial recurrent
Anterior tibial recurrent
Muscular branches
Anterior medial and lateral malleolar arteries
Termination: As dorsalis pedis artery.
Clinical relevance: Pulse felt between EHL and EDL tendons; absence suggests peripheral arterial obstruction.
Origin: Terminal branch of common peroneal nerve in lateral compartment.
Course:
Pierces anterior intermuscular septum to enter anterior compartment.
Descends with anterior tibial artery on interosseous membrane.
At ankle → lies lateral to anterior tibial artery, then passes beneath inferior extensor retinaculum to dorsum of foot.
Divides into medial and lateral terminal branches.
Branches:
Muscular: To tibialis anterior, EHL, EDL, and peroneus tertius.
Articular: To ankle and tarsal joints.
Cutaneous: Supplies skin of first interdigital cleft (between great and 2nd toe).
Applied anatomy: Injury causes foot drop due to paralysis of dorsiflexors; sensory loss in first web space.
Reflect deep fascia and identify the four muscles of the anterior compartment.
Note position of anterior tibial artery and deep peroneal nerve between TA and EDL.
Trace the artery through interosseous membrane and observe its continuation as dorsalis pedis artery.
Follow the deep peroneal nerve beneath the retinacula and on dorsum of foot; identify its terminal branches and their supply.
Demonstrate extensor digitorum brevis beneath tendons on dorsum.
Preserve synovial sheaths of tendons around the ankle for reference.
Foot Drop:
Due to injury or compression of common or deep peroneal nerve.
Loss of dorsiflexion → toes drag while walking; patient lifts leg high (steppage gait).
Anterior Compartment Syndrome:
Tight fascia limits expansion of swollen muscles, compressing artery and nerve.
Presents with pain, paresthesia, pallor, pulselessness, paralysis.
Treated by fasciotomy.
Tibialis Anterior Strain (Shin Splints):
Overuse injury with pain along tibial crest.
Arterial Palpation:
Dorsalis pedis artery pulse between tendons of EHL and EDL.
Nerve Testing:
Ask patient to dorsiflex foot and extend great toe; weakness = deep peroneal lesion.
The dorsum forms the upper surface of the foot, continuous above with the front of the leg.
Skin:
Thin, hairless, and freely mobile except where bound down over tendons.
More sensitive than skin of the sole.
Superficial fascia:
Contains dorsal venous arch, superficial nerves, and lymphatics.
Dorsal venous arch: main venous network just distal to ankle joint, connects to:
Medial side → Great saphenous vein.
Lateral side → Small saphenous vein.
Deep fascia:
Thin and continuous with inferior extensor retinaculum; encloses extensor digitorum brevis and extensor hallucis brevis.
Muscles:
Extensor digitorum brevis (EDB) → beneath long extensor tendons, divides into 4 slips to toes 2–4.
Extensor hallucis brevis (EHB) → medial part, to base of proximal phalanx of great toe.
Nerve supply: Deep peroneal nerve (lateral terminal branch).
Arterial supply: Dorsalis pedis artery and its branches.
Origin: Continuation of anterior tibial artery beyond the ankle joint.
Course:
Runs forward from midpoint between malleoli to proximal end of first intermetatarsal space.
Lies on capsule of ankle joint, then on tarsal bones and ligaments, covered only by skin and fascia.
Lateral to tendon of extensor hallucis longus and medial to tendon of extensor digitorum longus to 2nd toe.
Crossed superficially by the inferior extensor retinaculum and medial branch of deep peroneal nerve.
Branches:
Lateral tarsal artery – passes laterally beneath extensor digitorum brevis.
Medial tarsal arteries – small branches to medial tarsal region.
Arcuate artery – runs laterally across bases of metatarsals, gives off 2nd–4th dorsal metatarsal arteries.
First dorsal metatarsal artery – to great and second toes.
Deep plantar artery – passes between first and second metatarsals to join lateral plantar artery, completing the plantar arch.
Relations:
Accompanied by venae comitantes.
Crossed superficially by tendons and fascia but no strong muscular cover → easy for pulse palpation.
Make a longitudinal incision on dorsum of foot from ankle to base of toes.
Reflect skin laterally and medially to expose the superficial fascia.
Identify the dorsal venous arch, great and small saphenous veins, and superficial cutaneous nerves (superficial peroneal branches).
Remove superficial fascia to expose:
Tendons of extensor hallucis longus and extensor digitorum longus,
Extensor digitorum brevis, and
Dorsalis pedis artery beneath them.
Trace the dorsalis pedis artery distally, noting its branches.
Demonstrate deep peroneal nerve on lateral side of artery, dividing into its terminal branches near first intermetatarsal space.
Show the deep plantar branch piercing the first dorsal interosseous space to plantar aspect.
Dorsalis Pedis Pulse:
Palpated just lateral to tendon of extensor hallucis longus, midway between malleoli and first intermetatarsal space.
Absent or weak pulse indicates peripheral arterial disease or atherosclerosis.
Arterial Anastomosis:
Deep plantar branch joins lateral plantar artery to form plantar arch, ensuring collateral supply even if posterior tibial artery is blocked.
Extensor Digitorum Brevis Hypertrophy:
May mimic a dorsal foot swelling.
Injury to Deep Peroneal Nerve:
Leads to loss of sensation in first web space and weak extension of toes (EHB, EDB paralysis).
Arterial line:
Dorsalis pedis artery is a preferred site for arterial blood gas sampling or continuous pressure monitoring in critical care.
The lateral compartment of the leg lies between:
Anterior intermuscular septum (in front),
Posterior intermuscular septum (behind), and
Deep fascia of leg (superficially).
Contains:
Two muscles → Peroneus (Fibularis) Longus and Peroneus Brevis.
Nerve supply → Superficial peroneal nerve.
Blood supply → Branches of peroneal artery (from posterior compartment).
The deep fascia over this region is thick and continues below to form superior and inferior peroneal retinacula around the lateral malleolus.
1. Superior Peroneal Retinaculum
A fibrous band extending from the lateral malleolus to lateral surface of calcaneum.
Function: Binds tendons of peroneus longus and peroneus brevis behind the malleolus in a common synovial sheath.
Prevents bowstringing of tendons during eversion.
2. Inferior Peroneal Retinaculum
Lies below the lateral malleolus, extending from calcaneum to the inferior extensor retinaculum.
Peroneus brevis tendon runs above it, peroneus longus tendon below it — each within its own synovial sheath.
Continuous medially with inferior extensor retinaculum forming a fibrous sling over tendons.
Make an incision along the posterior border of fibula and reflect skin and superficial fascia.
Identify superficial peroneal nerve emerging in lower third of leg.
Expose and clean peroneal muscles lying superficial to fibula.
Follow their tendons posterior to lateral malleolus, showing their course under peroneal retinacula.
Demonstrate synovial sheaths and note the insertion sites of peroneus longus and brevis on foot.
Peroneal Tendon Subluxation:
Caused by tearing of superior peroneal retinaculum → tendons slip forward over malleolus.
Peroneal Muscle Weakness:
Leads to loss of eversion; foot tends to invert excessively (ankle sprain).
Common Peroneal Nerve Palsy:
Injury around neck of fibula → paralysis of lateral and anterior compartment muscles → foot drop.
Compartment Syndrome:
Tight deep fascia may compress nerve and vessels → pain, swelling, paresthesia.
1. Peroneus (Fibularis) Longus
Origin: Head and upper two-thirds of lateral surface of fibula.
Insertion: Base of 1st metatarsal and medial cuneiform (after passing through groove on cuboid).
Nerve: Superficial peroneal nerve (L5, S1, S2).
Action: Everts and plantarflexes foot; maintains transverse arch.
Special feature: Tendon crosses sole obliquely within a fibrous tunnel.
2. Peroneus (Fibularis) Brevis
Origin: Lower two-thirds of lateral surface of fibula.
Insertion: Tuberosity on base of 5th metatarsal.
Nerve: Superficial peroneal nerve (L5, S1, S2).
Action: Everts foot and assists plantarflexion.
Clinical note: Tendon commonly avulsed in ankle inversion injuries.
Avulsion Fracture of 5th Metatarsal:
Due to sudden violent contraction of peroneus brevis.
Sprain at Ankle:
Overstretching or tearing of lateral ligaments often involves peroneus longus/brevis strain.
Pes Cavus (high-arched foot):
May occur from imbalance between peroneal and tibialis anterior/posterior muscles.
Origin: Terminal branch of common peroneal nerve in lateral compartment (near fibular neck).
Course:
Descends between peroneus longus and brevis muscles.
Pierces deep fascia in lower third of leg to become cutaneous.
Divides into medial and intermediate dorsal cutaneous branches on dorsum of foot.
Distribution:
Muscular: to peroneus longus and brevis.
Cutaneous: supplies most of dorsum of foot and toes (except first web space and lateral border).
Articular: to ankle joint.
Identify nerve emerging through fascia about 7–10 cm above lateral malleolus.
Follow it distally as it divides into two branches spreading across dorsum of foot.
Trace proximal part to its entry between peroneal muscles; demonstrate muscular branches.
Preserve its cutaneous distribution over dorsal surface of toes.
Injury:
Causes sensory loss over anterolateral leg and dorsum of foot, with weakness of foot eversion.
Entrapment neuropathy:
Pain and tingling over dorsum of foot due to compression as it pierces deep fascia.
Nerve testing:
Ask patient to evert foot against resistance — weakness indicates lesion.
Lies between crest of tibia and posterior border of tibia.
Covered by thin skin and superficial fascia containing great saphenous vein and saphenous nerve.
Structures:
Skin: thin, adherent over tibial surface.
Superficial fascia: contains cutaneous veins and lymphatics.
Deep fascia: attached to anterior and medial margins of tibia; forms part of leg’s fascial envelope.
Muscles deep to fascia: mainly flexor digitorum longus posteriorly (not part of this dissection plane).
Incision along medial border of tibia.
Reflect skin to reveal great saphenous vein running anterior to medial malleolus.
Identify saphenous nerve accompanying the vein.
Note perforating veins connecting it to deep venous system.
Varicose veins:
Dilatation of great saphenous vein and its tributaries due to valve incompetence.
Venesection site:
Great saphenous vein can be accessed anterior to medial malleolus for cannulation.
Saphenous nerve entrapment:
Pain along medial leg and foot due to compression by tight fascia or trauma.
Shin abrasions:
The subcutaneous position of tibia makes it prone to injury with minimal protection.
1. Structures Passing Deep to Superior Extensor Retinaculum (Medial → Lateral):
👉 “Tom Has A Nervous Dog Pet”
T → Tibialis anterior
H → Extensor hallucis longus
A → Anterior tibial artery
N → Deep peroneal nerve
D → Extensor digitorum longus
P → Peroneus tertius
2. Branches of Anterior Tibial Artery:
👉 “Pretty Arteries Make Legs Alive”
P → Posterior tibial recurrent
A → Anterior tibial recurrent
M → Muscular branches
L → Lateral malleolar
A → Anterior medial malleolar
(Final continuation → Dorsalis pedis artery)
3. Branches of Dorsalis Pedis Artery:
👉 “Many Lovers Are Found Deep”
M → Medial tarsal arteries
L → Lateral tarsal artery
A → Arcuate artery
F → First dorsal metatarsal artery
D → Deep plantar artery (joins plantar arch)
4. Tendons on Front of Ankle (Medial → Lateral):
👉 “Tom Has Dirty Pants”
T → Tibialis anterior
H → Extensor hallucis longus
D → Extensor digitorum longus
P → Peroneus tertius
(Dorsalis pedis artery lies between H and D.)
5. Muscles of Anterior Compartment of Leg:
👉 “The Extra Energetic Person”
T → Tibialis anterior
E → Extensor hallucis longus
E → Extensor digitorum longus
P → Peroneus tertius
6. Nerve Supply of Leg (Remember the Rule):
👉 “Deep for Dorsiflexors, Superficial for Everters”
Deep peroneal nerve → Anterior compartment (dorsiflexors).
Superficial peroneal nerve → Lateral compartment (everters).
The anterior compartment of leg lies between the lateral surface of tibia and anterior intermuscular septum.
It contains four muscles — tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius — all supplied by the deep peroneal nerve.
The main artery of this compartment is the anterior tibial artery, the direct continuation of the popliteal artery through the interosseous membrane.
The dorsalis pedis artery is the continuation of the anterior tibial artery beyond the ankle joint; it supplies the dorsum of foot and contributes to the plantar arch through its deep plantar branch.
The deep peroneal nerve supplies all anterior-compartment muscles and the first interdigital cleft of skin; its injury leads to foot drop.
The superficial peroneal nerve innervates peroneus longus and peroneus brevis (lateral compartment) and provides cutaneous supply to most of the dorsum of foot except the first web space.
The peroneus longus tendon crosses the sole obliquely and helps maintain the transverse arch of foot.
The great saphenous vein passes in front of the medial malleolus, whereas the small saphenous vein passes behind the lateral malleolus.
The superior and inferior extensor retinacula hold the long extensor tendons in place and prevent bow-stringing during dorsiflexion.
Pulse of dorsalis pedis artery is felt lateral to the tendon of extensor hallucis longus in front of the ankle.
The tibial crest (shin) is subcutaneous and commonly bruised; the skin here is thin and tightly adherent to the periosteum.
Eversion of foot is produced by peroneus longus and brevis; inversion by tibialis anterior and posterior.
Anterior-compartment syndrome results from increased pressure under the tough deep fascia, compressing the anterior tibial artery and deep peroneal nerve.
Shin splints refer to pain along the tibia due to repetitive strain of tibialis anterior origin.
Q. A patient presents with inability to dorsiflex the foot and loss of sensation in the first web space. Which nerve is likely injured? What deformity results from it?
Answer:
The deep peroneal nerve is injured.
This nerve supplies all the muscles of the anterior compartment of the leg — tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius.
Paralysis of these muscles leads to loss of dorsiflexion of the ankle and extension of toes.
The foot assumes a plantar-flexed and inverted position because the unopposed action of gastrocnemius, soleus, and tibialis posterior pulls the foot downward and medially.
The condition is called foot drop.
Sensory loss occurs in the first interdigital cleft (between great and second toe), which is the cutaneous area supplied by the deep peroneal nerve.
Common causes include:
Compression or trauma to the common peroneal nerve as it winds around the neck of fibula.
Prolonged squatting, tight plaster casts, or compartment syndrome of anterior leg.
1. Q. A long-distance runner complains of pain and tenderness along the anterior border of tibia after excessive training. What is the probable diagnosis and cause?
Answer:
The condition is Shin Splints (Tibial Stress Syndrome).
Caused by repetitive traction on the periosteum at the origin of tibialis anterior and sometimes extensor digitorum longus.
It leads to inflammation of the periosteum and pain along the tibial crest.
Common in athletes, military recruits, and dancers.
Treatment: Rest, ice, and correction of footwear and running technique.
2. Q. Following a crush injury to the leg, the patient develops severe pain, pallor, and numbness over the dorsum of foot. What is the likely diagnosis?
Answer:
The presentation suggests Anterior Compartment Syndrome.
The deep fascia and intermuscular septa form tight compartments that resist expansion.
Bleeding or swelling inside the anterior compartment increases pressure, compressing the anterior tibial artery and deep peroneal nerve.
Results in pain, paresthesia, pallor, paralysis, and loss of pulse.
Treatment: Immediate fasciotomy to decompress the compartment and prevent necrosis of muscles and nerves.
3. Q. Why is the dorsalis pedis artery commonly palpated in clinical practice?
Answer:
It is superficially placed and easily accessible, lying just lateral to the tendon of extensor hallucis longus in front of the ankle.
It reflects the patency of the anterior tibial artery and is a vital indicator of peripheral arterial circulation.
Absent or weak pulse indicates peripheral arterial occlusive disease or diabetic microangiopathy.
4. Q. A person sustains a laceration over the dorsum of foot. The big toe cannot be extended. Which structure is likely cut?
Answer:
The tendon of extensor hallucis longus is likely injured.
The muscle originates from the fibula and extends the great toe.
Injury leads to loss of extension of the hallux and weakness in dorsiflexion.
5. Q. Why does injury to the common peroneal nerve at the neck of fibula cause both foot drop and loss of eversion?
Answer:
The common peroneal nerve divides into:
Deep peroneal nerve → supplies dorsiflexors (anterior compartment).
Superficial peroneal nerve → supplies everters (lateral compartment).
Injury before division leads to paralysis of both groups → loss of dorsiflexion (foot drop) and eversion, producing an inverted, plantarflexed foot.
6. Q. A fracture of the 5th metatarsal base occurs while playing football. Which muscle causes this avulsion and why?
Answer:
The peroneus brevis tendon inserts at the base of 5th metatarsal.
Sudden inversion of the foot causes violent contraction of peroneus brevis, pulling off the tuberosity → avulsion fracture.
Commonly seen in ankle sprain injuries.
7. Q. During injection around the ankle, why must care be taken not to injure the superficial veins and nerves?
Answer:
The great saphenous vein and saphenous nerve lie anterior to the medial malleolus, while the small saphenous vein and sural nerve lie posterior to the lateral malleolus.
Accidental injury leads to hematoma, nerve irritation, and persistent pain or numbness.
8. Q. A mountaineer suffers frostbite over the dorsum of foot. Which structure’s location explains the early ischemic changes in this region?
Answer:
The dorsalis pedis artery lies just beneath the thin skin and fascia, with minimal muscular cover.
Hence, it is highly susceptible to cold-induced vasospasm and thrombosis, leading to ischemic necrosis of overlying tissues.
9. Q. Why is the lateral side of the leg more prone to bruising and muscle injury during inversion sprains?
Answer:
The peroneal muscles are stretched or torn when the foot inverts suddenly.
The superior peroneal retinaculum may rupture, causing tendon subluxation over the lateral malleolus.
The overlying skin is thin, and fascia is tight, predisposing to localized hematoma.
10. Q. What is the clinical importance of the great saphenous vein on the medial side of leg?
Answer:
It is used for venous cutdown and coronary artery bypass grafting (CABG) due to its length and accessibility.
Lies anterior to medial malleolus, accompanied by saphenous nerve.
Careful dissection is needed to avoid nerve injury during harvesting.
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