Lower Limb — MCQs

A 49-year-old man presents with a cold and pale foot. Physical examination reveals peripheral vascular disease, with duplex ultrasound studies indicating possible occlusion of his popliteal artery and an absent posterior tibial artery pulse. What is the most common location for palpation of the posterior tibial artery pulse?

Q268Easy

The base of the femoral triangle is formed by which anatomical structure?

Q269Medium

A 56-year-old male with advanced bladder carcinoma suffers from difficulty while walking. Muscle testing reveals weakened adductors of the right thigh. Which nerve is most likely being compressed by the tumor to result in walking difficulty?

Q270Easy

Which is the least mobile metatarsal of the foot?

Lower Limb Indian Medical PG Practice Questions and MCQs

Question 261: An athlete is sitting on the edge of a table with knees flexed at 90 degrees. When the athlete fully extends their knee, what happens to the tibial tuberosity in relation to the patella?

A. No change
B. Movement of the tibial tuberosity towards the medial border of the patella
C. Movement of the tibial tuberosity towards the lateral border of the patella (Correct Answer)
D. Movement of the tibial tuberosity towards the center of the patella

Explanation: ### Explanation **Concept: The "Screw-Home" Mechanism and Q-Angle** The correct answer is **C**. This phenomenon is primarily due to the **"Screw-Home" mechanism** of the knee and the anatomical alignment of the quadriceps (Q-angle). When the knee moves from 90° flexion to full extension in a non-weight-bearing position (open kinetic chain), the **tibia undergoes obligatory external (lateral) rotation** during the final 20° of extension. Because the tibial tuberosity is the insertion point for the patellar ligament, this external rotation shifts the tuberosity laterally relative to the patella. Additionally, the lateral pull of the quadriceps muscle group (which has a naturally lateral vector) further contributes to this lateral displacement. **Analysis of Incorrect Options:** * **Option A:** Incorrect. The knee joint is not a simple hinge; it involves complex gliding and rotation. * **Option B:** Incorrect. Medial rotation of the tibia occurs during the "unlocking" of the knee (at the start of flexion), not during extension. * **Option D:** Incorrect. The tibial tuberosity starts relatively central but tracks laterally as the terminal extension "locks" the joint. **Clinical Pearls for NEET-PG:** * **Locking vs. Unlocking:** The knee is **locked** in full extension by **lateral rotation of the tibia** (open chain) or medial rotation of the femur (closed chain). It is **unlocked** by the **Popliteus muscle**, which medially rotates the tibia. * **Q-Angle:** A high Q-angle (common in females) increases the lateral tracking force on the patella, predisposing to patellofemoral pain syndrome or lateral dislocation. * **The "J-Sign":** In patients with patellar instability, the patella moves sharply lateral (like a letter 'J') during the final stages of extension as the tuberosity rotates.

Question 262: All of the following are contents of the adductor canal, EXCEPT?

A. Femoral artery
B. Popliteal artery (Correct Answer)
C. Nerve to Vastus medialis
D. Saphenous nerve

Explanation: The **Adductor Canal** (also known as Hunter’s canal or the Subsartorial canal) is an aponeurotic tunnel in the middle third of the thigh. It serves as a passage for structures moving from the femoral triangle to the popliteal fossa. ### **Why Option B is Correct** The **Popliteal artery** is the continuation of the femoral artery, but it only changes its name *after* it exits the adductor canal through the **adductor hiatus** (an opening in the Adductor magnus muscle). Therefore, the popliteal artery is a content of the popliteal fossa, not the adductor canal itself. ### **Why the Other Options are Incorrect** * **Femoral Artery (A):** This is the primary content of the canal. It enters at the apex of the femoral triangle and exits through the adductor hiatus. * **Nerve to Vastus Medialis (C):** This is the thickest muscular branch of the femoral nerve. it travels through the canal to supply the vastus medialis muscle. * **Saphenous Nerve (D):** This is the longest cutaneous branch of the femoral nerve. It travels through the canal but exits by piercing the fascial roof (vastoadductor membrane) to become superficial. ### **High-Yield NEET-PG Pearls** * **Boundaries:** Anterolateral (Vastus medialis), Posterior (Adductor longus and magnus), and Medial/Roof (Sartorius). * **Contents:** Femoral artery, Femoral vein, Saphenous nerve, and Nerve to vastus medialis. Note: The **Femoral nerve** itself is *not* a content; only its branches are. * **Clinical Significance:** The canal is a common site for an **Adductor Canal Block**, used for regional anesthesia in knee surgeries (e.g., TKR) because it provides sensory blockade via the saphenous nerve while sparing the motor function of the quadriceps (unlike a femoral nerve block).

Question 263: The condyles of the tibia provide attachment to which of the following?

A. Fibular collateral ligament
B. Tibial collateral ligament (Correct Answer)
C. Ligamentum patellae
D. Popliteus muscle

Explanation: The **Tibial Collateral Ligament (TCL)**, also known as the Medial Collateral Ligament (MCL), is a broad, flat band located on the medial aspect of the knee joint. It is the correct answer because its **superior attachment** is to the medial condyle of the femur, while its **inferior attachment** is to the **medial condyle and the medial surface of the shaft of the tibia**. ### Analysis of Options: * **Tibial Collateral Ligament (Correct):** It consists of superficial and deep parts. The superficial part attaches to the medial tibial condyle and the shaft, while the deep part is firmly attached to the **medial meniscus**. * **Fibular Collateral Ligament (Incorrect):** This is a cord-like ligament on the lateral side. It attaches from the lateral femoral condyle to the **head of the fibula**, not the tibia. * **Ligamentum Patellae (Incorrect):** This is the continuation of the quadriceps tendon. It attaches to the **tibial tuberosity**, which is located on the anterior aspect of the tibia, distal to the condyles. * **Popliteus Muscle (Incorrect):** While the popliteus originates from the lateral femoral condyle, it inserts into the **posterior surface of the tibia** (above the soleal line), not specifically the condyles. ### High-Yield NEET-PG Pearls: * **Clinical Correlation:** Because the TCL is attached to the medial meniscus, an injury to the TCL often results in a concomitant tear of the medial meniscus (part of the **O'Donoghue’s Unhappy Triad**: ACL, TCL, and Medial Meniscus). * **Morphology:** The TCL represents the degenerated tendon of the **Adductor Magnus** muscle. * **Stability:** The TCL is the primary stabilizer against **valgus stress** (abduction) of the knee.

Question 264: Positive Trendelenburg sign is seen in:

A. Superior gluteal nerve palsy (Correct Answer)
B. Inferior gluteal nerve palsy
C. Obturator nerve palsy
D. Ilihypogastric nerve palsy

Explanation: Explanation: The **Trendelenburg sign** is a clinical indicator of dysfunction in the hip abductor mechanism. To maintain a level pelvis when standing on one leg, the **Gluteus medius and Gluteus minimus** muscles must contract on the weight-bearing side to prevent the opposite side of the pelvis from sagging. 1. **Why Option A is Correct:** The **Superior Gluteal Nerve (L4–S1)** supplies the Gluteus medius, Gluteus minimus, and Tensor fasciae latae. If this nerve is paralyzed, the hip abductors on the supported side fail to stabilize the pelvis. Consequently, when the patient stands on the affected leg, the pelvis drops on the healthy (unsupported) side. This is a "Positive Trendelenburg Sign." 2. **Why Other Options are Incorrect:** * **Inferior Gluteal Nerve:** Supplies the Gluteus maximus. Palsy leads to difficulty rising from a sitting position or climbing stairs (Gluteus maximus lurch), but does not cause pelvic tilt. * **Obturator Nerve:** Supplies the adductors of the thigh. Injury results in loss of thigh adduction and sensory loss on the medial thigh. * **Iliohypogastric Nerve:** Supplies the abdominal muscles and skin over the pubis/iliac crest; it has no role in hip stability. **High-Yield Clinical Pearls for NEET-PG:** * **The "Sound" Rule:** In a positive Trendelenburg test, the pelvis sinks on the **sound** (healthy) side, but the lesion is on the **supported** (standing) side. * **Trendelenburg Gait:** When the patient walks with this deficit, they compensate by tilting their trunk toward the affected side to shift the center of gravity; this is known as a **Lurching gait**. * **Common Causes:** Polio, Slipped Capital Femoral Epiphysis (SCFE), and iatrogenic injury during intramuscular injections in the gluteal region.

Question 265: A 17-year-old boy was stabbed, resulting in the transection of the obturator nerve. Which of the following muscles is completely paralyzed?

A. Pectineus
B. Adductor magnus
C. Adductor longus (Correct Answer)
D. Biceps femoris

Explanation: ### Explanation The **obturator nerve (L2–L4)** is the primary motor nerve of the medial compartment of the thigh. It supplies the adductor group of muscles, which are responsible for adducting the hip. **Why Adductor Longus is the Correct Answer:** The **Adductor longus** is supplied **solely** by the anterior division of the obturator nerve. Therefore, a complete transection of the obturator nerve results in its total paralysis. **Analysis of Incorrect Options:** * **Pectineus:** This is a "hybrid" or "composite" muscle. It is primarily supplied by the **femoral nerve**, though it occasionally receives a small branch from the obturator nerve. It would not be completely paralyzed. * **Adductor magnus:** This is also a hybrid muscle. Its adductor part is supplied by the **obturator nerve**, but its "hamstring part" (ischiocondylar portion) is supplied by the "tibial component of the sciatic nerve". * **Biceps femoris:** This is a muscle of the posterior compartment (hamstrings). The long head is supplied by the tibial part of the sciatic nerve, and the short head by the common peroneal part. It has no innervation from the obturator nerve. **High-Yield NEET-PG Pearls:** 1. **Hybrid Muscles of the Lower Limb:** * **Adductor Magnus:** Obturator + Sciatic (Tibial part) * **Pectineus:** Femoral + Obturator (Variable) * **Biceps Femoris:** Tibial + Common Peroneal (Sciatic nerve) 2. **Obturator Nerve Course:** It enters the thigh through the **obturator canal** and divides into anterior and posterior divisions around the **adductor brevis** muscle. 3. **Clinical Sign:** Injury to the obturator nerve leads to a significant loss of thigh adduction and a characteristic "swinging" gait.

Question 266: A 22-year-old man presents after a bicycle accident with a tibial fracture above the ankle. Physical examination reveals a severed tibial nerve on the posterior aspect of the tibia. Which of the following signs will most likely be present during physical examination?

A. Sensory loss of the dorsum of the foot
B. Sensory loss on the sole of the foot (Correct Answer)
C. Foot drop
D. Paralysis of the extensor digitorum brevis

Explanation: The **tibial nerve** is the larger terminal branch of the sciatic nerve (L4–S3). It descends through the popliteal fossa and passes deep to the flexor retinaculum at the ankle (tarsal tunnel). **1. Why the Correct Answer is Right:** The tibial nerve provides sensory innervation to the **entire sole of the foot** via its terminal branches: the medial and lateral plantar nerves. It also gives off the medial calcaneal branches to the heel. A severance of the nerve above the ankle interrupts these pathways, leading to anesthesia of the plantar surface. Additionally, it supplies the intrinsic muscles of the sole; however, sensory loss is a hallmark clinical finding in such injuries. **2. Why the Incorrect Options are Wrong:** * **Option A & D:** The **dorsum of the foot** and the **extensor digitorum brevis** are supplied by the **deep peroneal nerve** (a branch of the common peroneal nerve). Injury to the tibial nerve does not affect the anterior compartment of the leg or the dorsal intrinsic muscles. * **Option C:** **Foot drop** is caused by paralysis of the dorsiflexors (tibialis anterior), which are supplied by the **deep peroneal nerve**. Tibial nerve injury actually results in the inability to plantarflex (loss of "push-off") and a deformity known as **calcaneovalgus**. **3. NEET-PG High-Yield Pearls:** * **Tarsal Tunnel Syndrome:** Compression of the tibial nerve behind the medial malleolus, causing pain/paresthesia in the sole. * **Mnemonic for Tarsal Tunnel (Ant to Post):** **T**ibialis posterior, flexor **D**igitorum longus, posterior tibial **A**rtery, tibial **V**ein, tibial **N**erve, flexor **H**allucis longus (**T**om, **D**ick **A**nd **V**ery **N**ervous **H**arry). * **Reflex:** The tibial nerve mediates the **Achilles (Ankle) jerk (S1, S2)**.

Question 267: A 49-year-old man presents with a cold and pale foot. Physical examination reveals peripheral vascular disease, with duplex ultrasound studies indicating possible occlusion of his popliteal artery and an absent posterior tibial artery pulse. What is the most common location for palpation of the posterior tibial artery pulse?

A. Lateral to the muscular belly of the abductor hallucis
B. Posteroinferior to the medial femoral condyle
C. Groove midway between the lateral malleolus and the calcaneus
D. Groove midway between the medial malleolus and the calcaneus (Correct Answer)

Explanation: **Explanation:** The **posterior tibial artery** is one of the two terminal branches of the popliteal artery. It descends through the deep posterior compartment of the leg and enters the foot by passing deep to the **flexor retinaculum** (laciniate ligament). **Why Option D is Correct:** The most reliable location to palpate the posterior tibial artery pulse is in the **groove midway between the medial malleolus and the calcaneus**. At this point, the artery is relatively superficial before it divides into the medial and lateral plantar arteries. This is a critical clinical landmark used to assess peripheral arterial disease (PAD) and the vascular integrity of the lower limb [1]. **Analysis of Incorrect Options:** * **Option A:** The abductor hallucis muscle lies distal to the flexor retinaculum. While the artery eventually passes deep to this muscle, it is too deep for reliable palpation at this site. * **Option B:** This describes the region of the knee. The popliteal artery is palpated deep in the popliteal fossa, not the posterior tibial artery. * **Option C:** This is the location for palpating the **peroneal (fibular) artery**, though it is rarely palpable. The lateral malleolus is a landmark for the sural nerve and small saphenous vein. **NEET-PG High-Yield Pearls:** * **Tarsal Tunnel Contents:** From anterior to posterior (Mnemonic: **T**om, **D**ick, **A**nd **V**ery **N**ervous **H**arry): **T**ibialis posterior, flexor **D**igitorum longus, posterior tibial **A**rtery, posterior tibial **V**ein, tibial **N**erve, flexor **H**allucis longus. * **Ankle-Brachial Index (ABI):** The posterior tibial pulse is essential for calculating the ABI; a ratio <0.9 indicates peripheral vascular disease [1]. * **Dorsalis Pedis Pulse:** Palpated on the dorsum of the foot, lateral to the tendon of the extensor hallucis longus.

Question 268: The base of the femoral triangle is formed by which anatomical structure?

A. Inguinal ligament (Correct Answer)
B. Medial border of sartorius muscle
C. Medial border of adductor longus muscle
D. Iliacus muscle

Explanation: The **femoral triangle** is a subfascial space located in the upper one-third of the anterior thigh. To answer this question, one must visualize the triangle as an inverted pyramid where the "base" is superior and the "apex" points inferiorly. ### **Explanation of the Correct Answer** * **A. Inguinal Ligament:** This structure forms the **base** (superior boundary) of the femoral triangle [1]. It stretches from the anterior superior iliac spine (ASIS) to the pubic tubercle. It acts as a functional "retaining band" for structures passing from the pelvis to the lower limb. ### **Analysis of Incorrect Options** * **B. Medial border of sartorius:** This forms the **lateral boundary** of the triangle. * **C. Medial border of adductor longus:** This forms the **medial boundary**. Note: The apex of the triangle is where the medial border of the sartorius crosses the medial border of the adductor longus. * **D. Iliacus muscle:** Along with the psoas major, pectineus, and adductor longus, the iliacus forms the **floor** of the triangle, not its boundaries. ### **High-Yield Clinical Pearls for NEET-PG** 1. **Contents (Lateral to Medial):** Remember the mnemonic **NAVEL** (Femoral **N**erve, **A**rtery, **V**ein, **E**mpty space/Femoral canal, **L**ymphatics). 2. **Femoral Sheath:** This fascial envelope encloses the femoral artery, vein, and canal, but **excludes the femoral nerve**, which lies lateral to the sheath. 3. **Clinical Significance:** The femoral triangle is the site for femoral hernia (specifically the femoral canal) [1], femoral artery catheterization, and palpation of the femoral pulse (mid-inguinal point). 4. **Roof:** Formed by the skin, superficial fascia, and fascia lata (containing the cribriform fascia and the great saphenous vein opening).

Question 269: A 56-year-old male with advanced bladder carcinoma suffers from difficulty while walking. Muscle testing reveals weakened adductors of the right thigh. Which nerve is most likely being compressed by the tumor to result in walking difficulty?

A. Femoral
B. Obturator (Correct Answer)
C. Common fibular (peroneal)
D. Tibial

Explanation: **Explanation:** The patient presents with weakness in the **adductors of the thigh**, which is the hallmark sign of **Obturator nerve** involvement. **1. Why Obturator Nerve is Correct:** The obturator nerve (L2–L4) originates from the lumbar plexus and descends through the pelvis. It passes along the lateral wall of the lesser pelvis, specifically near the **ovaries (in females)** and the **internal iliac lymph nodes**. In this case, advanced bladder carcinoma likely metastasized to the pelvic lymph nodes or directly invaded the lateral pelvic wall, compressing the nerve. The obturator nerve provides motor innervation to the **medial compartment of the thigh** (Adductor longus, brevis, magnus, and Gracilis). Weakness in these muscles leads to difficulty in stabilizing the pelvis and adducting the leg during the gait cycle. **2. Why Other Options are Incorrect:** * **Femoral Nerve (L2–L4):** Innervates the anterior compartment of the thigh (e.g., Quadriceps). Damage would cause loss of knee extension and hip flexion, not isolated adduction weakness. * **Common Fibular Nerve (L4–S2):** A branch of the sciatic nerve. Compression leads to "Foot Drop" due to paralysis of the anterior and lateral leg compartments. * **Tibial Nerve (L4–S3):** Innervates the posterior compartment of the leg. Damage results in an inability to plantarflex the foot. **3. High-Yield Clinical Pearls for NEET-PG:** * **Howship-Romberg Sign:** Pain/paresthesia on the medial aspect of the thigh due to obturator nerve compression (often seen in obturator hernias). * **Referred Pain:** Because the obturator nerve also supplies the hip and knee joints, pelvic pathology can sometimes present as isolated knee pain. * **Anatomy:** It is the only nerve of the lumbar plexus that emerges from the **medial** border of the psoas major muscle.

Question 270: Which is the least mobile metatarsal of the foot?

A. 1st metatarsal
B. 2nd metatarsal (Correct Answer)
C. 3rd metatarsal
D. 4th metatarsal

Explanation: The **2nd metatarsal** is the least mobile metatarsal of the foot because it is firmly "wedged" into a mortise formed by the three cuneiform bones. ### Why the 2nd Metatarsal is the Correct Answer: The base of the 2nd metatarsal is recessed proximally compared to the 1st and 3rd metatarsals. It fits tightly into a socket created by the **shorter intermediate cuneiform**, flanked by the medial and lateral cuneiforms. This anatomical arrangement, often compared to a "keystone" in an arch, provides maximum stability to the longitudinal arch of the foot but results in negligible mobility. ### Why the Other Options are Incorrect: * **1st Metatarsal:** It is relatively mobile to allow for the push-off phase of gait. It has its own joint capsule and does not have intermetatarsal ligaments connecting it to the 2nd metatarsal, allowing for a greater range of motion. * **3rd Metatarsal:** While less mobile than the 4th and 5th, it is not as rigidly fixed as the 2nd because its articulation with the lateral cuneiform does not involve a recessed mortise. * **4th and 5th Metatarsals:** These are the most mobile metatarsals (especially the 5th). They articulate with the cuboid, allowing for significant dorsiflexion and plantarflexion to help the foot adapt to uneven terrain. ### High-Yield Clinical Pearls for NEET-PG: * **Lisfranc Joint:** The tarsometatarsal joint complex. The 2nd metatarsal base acts as the primary stabilizer. * **Lisfranc Ligament:** An oblique band connecting the **medial cuneiform to the base of the 2nd metatarsal**. It is the strongest ligament supporting this joint. * **March Fracture:** Because the 2nd metatarsal is the most rigid, it is the most common site for stress fractures (March fractures) in hikers or athletes, as it absorbs the highest amount of stress during walking.

Practice by Chapter

Gluteal Region and Hip

Practice Questions

Thigh and Popliteal Fossa

Practice Questions

Leg and Foot

Practice Questions

Joints of Lower Limb

Practice Questions

Nerves of Lower Limb

Practice Questions

Arterial Supply and Venous Drainage

Practice Questions

Lymphatic Drainage

Practice Questions

Muscles and Their Actions

Practice Questions

Gait Analysis and Biomechanics

Practice Questions

Applied Anatomy and Clinical Correlations

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Lower Limb — MCQs

Lower Limb — MCQs

On this page

Practice by Chapter

Want unlimited practice?