A 64-year-old man on warfarin for atrial fibrillation has an INR of 6.2 and severe pain in the right groin. CT shows a large iliacus haematoma. He cannot straighten his right knee against gravity, the knee jerk is absent and the front of the thigh and the medial side of the leg are numb. Which nerve has the haematoma compressed?

Lateral cutaneous nerve of the thigh

A 30-year-old car driver's knee hit the dashboard in a head-on collision. He has a posterior dislocation of the left hip and, after reduction, cannot dorsiflex the left ankle, while plantar flexion is only mildly weak. Which part of the nerve injury explains this pattern?

Common peroneal division of the sciatic nerve

Tibial division of the sciatic nerve

In the ICU, a resident has to insert a central venous catheter into the right femoral vein of a patient in shock. She palpates the femoral artery pulse just below the inguinal ligament. Where should she insert the needle?

Just medial to the arterial pulse

Just lateral to the arterial pulse

Directly over the arterial pulse

Lower limb nerves, gait and compartments

16 NEET-PG practice questions on Lower limb nerves, gait and compartments, part of Anatomy. The first 16 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 28-year-old man develops a lurching walk a week after an intramuscular injection in the right buttock at a village clinic. When he stands on his right leg alone, the left side of his pelvis sags. Which nerve is injured?
1. ARight sciatic nerve
2. BRight inferior gluteal nerve
3. CRight superior gluteal nerve
4. DLeft superior gluteal nerve
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Answer: C · Right superior gluteal nerve
A positive Trendelenburg sign means the abductors of the stance-side hip cannot hold the pelvis level. When he stands on the right leg, the right gluteus medius and minimus must lift the opposite side; the left side sags, so the right superior gluteal nerve (L4, L5, S1) is damaged. The sign is named for the side bearing weight, not the side that drops. Injections should go into the upper outer quadrant of the buttock or the ventrogluteal site to avoid the gluteal and sciatic nerves.
- A: Sciatic injury causes foot drop and posterior thigh weakness, not a Trendelenburg sign.
- B: Inferior gluteal palsy weakens gluteus maximus: difficulty rising from a chair or climbing stairs.
- D: A left-sided lesion would make the right pelvis sag when standing on the left leg.
Question 2 · Medium
A 64-year-old man on warfarin for atrial fibrillation has an INR of 6.2 and severe pain in the right groin. CT shows a large iliacus haematoma. He cannot straighten his right knee against gravity, the knee jerk is absent and the front of the thigh and the medial side of the leg are numb. Which nerve has the haematoma compressed?
1. ALateral cutaneous nerve of the thigh
2. BFemoral nerve
3. CObturator nerve
4. DLumbosacral trunk
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Answer: B · Femoral nerve
The femoral nerve (L2 to L4) runs in the groove between psoas and iliacus, deep to the iliac fascia, so an iliacus haematoma can compress it. It supplies quadriceps (knee extension and the knee jerk), the skin of the front of the thigh, and through the saphenous nerve the medial side of the leg. This combination places the lesion in the femoral nerve. Reversing anticoagulation and treating the haematoma come first.
- A: The lateral cutaneous nerve of the thigh is purely sensory to the lateral thigh.
- C: Obturator nerve injury weakens thigh adduction and numbs the medial thigh.
- D: The lumbosacral trunk (L4, L5) feeds the sciatic nerve and does not supply quadriceps.
Question 3 · Medium
A 30-year-old car driver's knee hit the dashboard in a head-on collision. He has a posterior dislocation of the left hip and, after reduction, cannot dorsiflex the left ankle, while plantar flexion is only mildly weak. Which part of the nerve injury explains this pattern?
1. ATibial division of the sciatic nerve
2. BFemoral nerve
3. CSuperior gluteal nerve
4. DCommon peroneal division of the sciatic nerve
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Answer: D · Common peroneal division of the sciatic nerve
The sciatic nerve lies directly behind the hip joint, so a posterior dislocation can stretch it. Its common peroneal (lateral) division is the more often and more severely affected part, being more tightly tethered and having less supporting tissue, so foot drop dominates. The tibial division supplies plantar flexion, which is only mildly weak here. Sciatic function is tested and recorded before and after reduction.
- A: Tibial division damage would mainly weaken plantar flexion and numb the sole.
- B: The femoral nerve lies in front of the hip and supplies the knee extensors.
- C: Superior gluteal injury causes a Trendelenburg sign, not foot drop.
Question 4 · Medium
A 9-year-old boy with residual poliomyelitis of the left leg walks by pushing his left thigh backwards with his left hand each time he puts weight on that leg. Paralysis of which muscle group explains this gait?
1. ACalf muscles
2. BQuadriceps femoris
3. CGluteus medius
4. DHamstrings
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Answer: B · Quadriceps femoris
When quadriceps is paralysed, the knee tends to buckle into flexion as weight comes on to the limb. Pressing the lower thigh backwards with the hand keeps the knee in hyperextension, where it is stable without muscle action. This hand-to-knee gait is typical of post-polio quadriceps paralysis, a common residual deformity in India. A knee-ankle-foot orthosis with a knee lock can replace the hand.
- A: Calf paralysis causes a calcaneus gait with poor push-off.
- C: Gluteus medius paralysis causes a Trendelenburg (lurching) gait.
- D: Hamstring paralysis does not make the knee buckle on weight bearing.
Question 5 · Easy
In the ICU, a resident has to insert a central venous catheter into the right femoral vein of a patient in shock. She palpates the femoral artery pulse just below the inguinal ligament. Where should she insert the needle?
1. AAt the pubic tubercle
2. BJust medial to the arterial pulse
3. CJust lateral to the arterial pulse
4. DDirectly over the arterial pulse
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Answer: B · Just medial to the arterial pulse
In the femoral triangle, from lateral to medial, lie the femoral nerve, femoral artery, femoral vein and femoral canal. The vein lies just medial to the artery, so the needle is placed about a finger's breadth medial to the pulse, below the inguinal ligament. Ultrasound guidance is now preferred because it reduces arterial puncture. A puncture above the inguinal ligament risks retroperitoneal bleeding.
- A: The pubic tubercle is medial to the femoral canal and the vein.
- C: The femoral nerve lies lateral to the artery.
- D: A needle over the pulse enters the femoral artery.
Question 6 · Hard
A 36-year-old woman was given an intramuscular injection in the lower inner part of the right buttock at a private clinic. She now has foot drop, inability to stand on her toes and weak knee flexion. Sensation is lost below the knee except along the medial side of the leg and foot. Hip abduction is normal and there is no Trendelenburg sign. Where is the nerve injury most likely?
1. ATibial nerve in the popliteal fossa
2. BSciatic nerve in the gluteal region
3. CCommon peroneal nerve at the fibular neck
4. DL4 nerve root
Answer and explanation in LearnFree account
Question 7 · Easy
A 50-year-old woman had a deep abscess in her right buttock drained. A month later she finds it hard to climb stairs and to stand up from a squatting position, though walking on level ground is nearly normal. Which nerve is most likely damaged?
1. ASuperior gluteal nerve
2. BInferior gluteal nerve
3. CFemoral nerve
4. DObturator nerve
Answer and explanation in LearnFree account
Question 8 · Medium
A 46-year-old traffic constable who stands for long hours has burning pain and tingling in the sole of the left foot, worse at night. Tapping behind and below the medial malleolus reproduces the tingling into the sole. Ankle movements are full and there is no back pain. Where is the nerve most likely compressed?
1. ADeep peroneal nerve under the extensor retinaculum
2. BTibial nerve under the flexor retinaculum
3. CSural nerve behind the lateral malleolus
4. DSaphenous nerve in front of the medial malleolus
Answer and explanation in LearnFree account
Question 9 · Medium
A 27-year-old man had his tibial fracture fixed with an intramedullary nail. Overnight he develops severe pain on the front of the leg that is worse on passive flexion of the toes. The front of the leg is tense, and the only sensory change is numbness of the skin between the first and second toes on the dorsum. Which nerve is being compressed?
1. ASural nerve
2. BSuperficial peroneal nerve
3. CSaphenous nerve
4. DDeep peroneal nerve
Answer and explanation in LearnFree account
Question 10 · Easy
A 40-year-old man has a below-knee plaster cast for an ankle fracture. Three days later he cannot dorsiflex his foot or toes, and he has numbness over the lateral side of the leg and the dorsum of the foot. Pressure from the cast at which site has most likely caused this?
1. AMedial malleolus
2. BPopliteal fossa
3. CNeck of the fibula
4. DHead of the femur
Answer and explanation in LearnFree account
Question 11 · Hard
A 58-year-old farmer from Nashik, who has lost 9 kg after a long illness and spends hours squatting in his fields, develops a right foot drop over two weeks. The orthopaedic resident considers four findings that would favour a common peroneal nerve palsy over an L5 root lesion: 1. Normal strength of foot inversion. 2. A normal ankle jerk. 3. Numbness of the lateral leg and dorsum of the foot. 4. Weakness of hip abduction. Which findings are expected in a common peroneal nerve palsy?
1. AFindings 1, 2 and 3 only
2. BFindings 1, 3 and 4 only
3. CFindings 1 and 3 only
4. DFindings 2, 3 and 4 only
Answer and explanation in LearnFree account
Question 12 · Medium
A 72-year-old thin woman from a village in Odisha has a small, tender swelling below the inguinal ligament on the right. She is taken up for femoral hernia repair, and the surgical resident reviews four statements about the region: 1. The femoral nerve lies outside the femoral sheath. 2. The femoral canal contains a lymph node and fat. 3. The femoral vein lies lateral to the femoral artery. 4. A femoral hernia emerges below and lateral to the pubic tubercle. Which statements are correct?
1. AStatements 1 and 2 only
2. BStatements 2, 3 and 4 only
3. CStatements 1, 2, 3 and 4
4. DStatements 1, 2 and 4 only
Answer and explanation in LearnFree account
Question 13 · Hard
A 25-year-old man's leg is crushed under a fallen wall and the tibia is fixed. Six hours later he has severe leg pain needing repeated opioids, pain on passive stretch of the toes and a tense leg. Distal pulses are present. His BP is 120/70 mmHg and the anterior compartment pressure is 56 mmHg. What is the next best step?
1. AElevate the leg well above heart level
2. BUrgent fasciotomy of all four compartments
3. CDoppler study of the tibial arteries
4. DRepeat the pressure reading in 6 hours
Answer and explanation in LearnFree account
Question 14 · Medium
A 33-year-old man was struck on the lateral side of the leg by a cricket ball. He now has weakness when turning the sole of his foot outwards and numbness over most of the dorsum of the foot, but sensation in the first web space and dorsiflexion of the ankle are normal. Which nerve is injured?
1. ACommon peroneal nerve
2. BSuperficial peroneal nerve
3. CTibial nerve
4. DDeep peroneal nerve
Answer and explanation in LearnFree account
Question 15 · Medium
A 41-year-old woman had stripping of the long saphenous vein down to the ankle for varicose veins. At follow-up she complains of numbness along the medial side of the leg and the medial border of the foot. Which nerve has been injured?
1. ASuperficial peroneal nerve
2. BSural nerve
3. CMedial plantar nerve
4. DSaphenous nerve
Answer and explanation in LearnFree account
Question 16 · Medium
A 70-year-old woman falls in her courtyard and sustains a supracondylar fracture of the femur. The X-ray shows the distal fragment tilted backwards into the popliteal fossa, and the dorsalis pedis pulse is absent. Which structure lies deepest in the popliteal fossa and is therefore most at risk?
1. ATibial nerve
2. BPopliteal artery
3. CCommon peroneal nerve
4. DPopliteal vein
Answer and explanation in LearnFree account

Lower limb nerves, gait and compartments

A 28-year-old man develops a lurching walk a week after an intramuscular injection in the right buttock at a village clinic. When he stands on his right leg alone, the left side of his pelvis sags. Which nerve is injured?

A 30-year-old car driver's knee hit the dashboard in a head-on collision. He has a posterior dislocation of the left hip and, after reduction, cannot dorsiflex the left ankle, while plantar flexion is only mildly weak. Which part of the nerve injury explains this pattern?

A 9-year-old boy with residual poliomyelitis of the left leg walks by pushing his left thigh backwards with his left hand each time he puts weight on that leg. Paralysis of which muscle group explains this gait?

In the ICU, a resident has to insert a central venous catheter into the right femoral vein of a patient in shock. She palpates the femoral artery pulse just below the inguinal ligament. Where should she insert the needle?

A 50-year-old woman had a deep abscess in her right buttock drained. A month later she finds it hard to climb stairs and to stand up from a squatting position, though walking on level ground is nearly normal. Which nerve is most likely damaged?

A 40-year-old man has a below-knee plaster cast for an ankle fracture. Three days later he cannot dorsiflex his foot or toes, and he has numbness over the lateral side of the leg and the dorsum of the foot. Pressure from the cast at which site has most likely caused this?

A 33-year-old man was struck on the lateral side of the leg by a cricket ball. He now has weakness when turning the sole of his foot outwards and numbness over most of the dorsum of the foot, but sensation in the first web space and dorsiflexion of the ankle are normal. Which nerve is injured?

A 41-year-old woman had stripping of the long saphenous vein down to the ankle for varicose veins. At follow-up she complains of numbness along the medial side of the leg and the medial border of the foot. Which nerve has been injured?

A 70-year-old woman falls in her courtyard and sustains a supracondylar fracture of the femur. The X-ray shows the distal fragment tilted backwards into the popliteal fossa, and the dorsalis pedis pulse is absent. Which structure lies deepest in the popliteal fossa and is therefore most at risk?