Lower Limb Practice Questions

Q: A 27-year-old female wearing high heels sustained an inversion injury at the ankle. Which ligament is most likely to be injured?

Anterior talofibular ligament. Explanation: The ankle joint is most vulnerable to injury when in **plantarflexion**, which is the position the foot assumes while wearing high heels. In this position, the narrow posterior part of the talus sits in the mortise, making the joint relatively unstable. An **inversion injury** (the most common type of ankle sprain) puts excessive stress on the lateral collateral ligaments. **1. Why Anterior Talofibular Ligament (ATFL) is correct:** The ATFL is the weakest of the lateral ligaments. It is the first ligament to be stretched and torn during an inversion injury, especially when the foot is plantarflexed. It runs from the anterior margin of the lateral malleolus to the neck of the talus. **2. Why the other options are incorrect:** * **Calcaneofibular Ligament (CFL):** This is the second most commonly injured ligament. It is typically injured only after the ATFL has already been ruptured or during severe inversion in a neutral (dorsiflexed) position. * **Posterior Talofibular Ligament (PTFL):** This is the strongest of the lateral ligaments and is rarely injured except in complete ankle dislocations. * **Deltoid Ligament:** This is a very strong, fan-shaped ligament on the **medial** side of the ankle. It resists eversion, not inversion. **High-Yield Clinical Pearls for NEET-PG:** * **Sequence of injury:** ATFL (most common) → CFL → PTFL (least common). * **Anterior Drawer Test:** Used clinically to assess the integrity of the ATFL. * **Talar Tilt Test:** Used to assess the integrity of the CFL. * **Pott’s Fracture:** Involves forced eversion, often resulting in a tear of the deltoid ligament or avulsion of the medial malleolus.

Q: In inversion of the foot, the sole will face:

Medially. ### Explanation **Concept Overview:** Inversion and eversion are complex movements of the foot that occur primarily at the **subtalar** and **transverse tarsal (talocalcaneonavicular and calcaneocuboid) joints**. **1. Why "Medially" is Correct:** **Inversion** is the movement where the medial border of the foot is elevated, causing the **sole of the foot to face medially** (towards the midline of the body). This movement is primarily produced by the **Tibialis Anterior** and **Tibialis Posterior** muscles. It is often associated with adduction and plantarflexion of the foot. **2. Analysis of Incorrect Options:** * **Laterally (Option C):** This describes **Eversion**. In eversion, the lateral border of the foot is raised, and the sole faces laterally (away from the midline). This is primarily performed by the Peroneus (Fibularis) Longus and Brevis. * **Upwards/Downwards (Options A & B):** These terms do not accurately describe the rotational nature of inversion/eversion. Movement of the entire foot "upwards" is **Dorsiflexion**, while "downwards" is **Plantarflexion**, both of which occur at the ankle (talocrural) joint. **3. Clinical Pearls for NEET-PG:** * **Joint Involvement:** Remember that Dorsiflexion/Plantarflexion occurs at the **Ankle joint**, while Inversion/Eversion occurs at the **Subtalar joint**. * **Nerve Supply:** Inversion is performed by muscles supplied by the Deep Peroneal and Tibial nerves. Eversion is the hallmark function of the **Superficial Peroneal nerve**. * **Injury Pattern:** Inversion is the most common mechanism for **ankle sprains**, typically injuring the **Anterior Talofibular Ligament (ATFL)**. * **Axis:** Inversion and eversion occur around an oblique axis, not a simple cardinal plane.

Q: Which of the following muscles acts as the unlocker of the knee?

Popliteus. **Explanation:** The **Popliteus** is famously known as the **"Key to the knee"** because it initiates the process of "unlocking" the knee joint from a fully extended position to allow flexion. **Mechanism of Action:** When the knee is fully extended and weight-bearing, the femur rotates medially on the tibia to "lock" the joint (the locking mechanism). To initiate flexion, the Popliteus muscle contracts, causing **lateral rotation of the femur on the fixed tibia**. This rotation "unlocks" the joint, allowing flexion to proceed. In non-weight-bearing positions, it acts by medially rotating the tibia on the femur. **Analysis of Incorrect Options:** * **Gracilis & Sartorius:** These are members of the "Pes Anserinus" group. While they act as weak flexors and medial rotators of the leg, they do not possess the specific mechanical advantage or anatomical position required to initiate the unlocking process. * **Biceps Femoris:** This is a lateral rotator of the leg at the knee joint (when the knee is flexed). However, it is a primary flexor and does not participate in the initial unlocking phase of the screw-home mechanism. **High-Yield Clinical Pearls for NEET-PG:** * **Origin:** Lateral surface of the lateral condyle of the femur (intracapsular but extrasynovial). * **Insertion:** Posterior surface of the tibia above the soleal line. * **Nerve Supply:** Tibial Nerve (L4, L5, S1). * **The "Screw-Home" Mechanism:** Refers to the rotation between the tibia and femur at the end of extension (locking) and the beginning of flexion (unlocking). * **Morphology:** It is considered the "remnant" of the long flexor of the hallux in lower animals.

Q: The artery that is palpated between the medial malleolus and the calcaneal tendon is?

Posterior tibial artery. ***Posterior tibial artery*** - This artery passes through the **tarsal tunnel**, located just posterior to the **medial malleolus** and anterior to the **calcaneal (Achilles) tendon**, making it the palpable artery at this specific site. - The **posterior tibial artery** pulse is a critical component of the lower limb vascular examination, essential for assessing blood supply to the foot, especially in cases of **peripheral arterial disease** [1]. *Anterior tibial artery* - This artery is located on the **anterior aspect** of the leg and ankle, running down the front of the leg between the tibia and fibula. - It becomes the **dorsalis pedis artery** as it crosses the ankle joint, so it is not found behind the medial malleolus. *Dorsalis pedis artery* - This artery is palpated on the **dorsum (top) of the foot**, typically lateral to the tendon of the extensor hallucis longus. - As a continuation of the **anterior tibial artery**, its pulse point is anatomically distinct from the area between the medial malleolus and the calcaneal tendon. *Popliteal artery* - The **popliteal artery** is found deep within the **popliteal fossa**, the space behind the knee joint. - It is a much more proximal vessel that bifurcates into the **anterior and posterior tibial arteries** well above the ankle.

Q: A man sustained trauma on the lateral side of his right knee. Two days later, he complains of difficulty in walking, as his toes keep dragging on the ground. He also notices numbness over the upper lateral aspect of the leg and dorsum of the foot. Which nerve is most likely injured?

Common peroneal nerve. ***Common peroneal nerve***- The **common peroneal nerve** (fibular nerve) curves superficially around the neck of the **fibula**, making it the most vulnerable nerve in the lower extremity to direct trauma on the lateral side of the knee.- Injury to the common peroneal nerve results in paralysis of the muscles responsible for **dorsiflexion** (deep peroneal branch) and **eversion** (superficial peroneal branch), leading to the characteristic 'foot drop' and difficulty clearing the toes, as well as sensory loss over the dorsum of the foot.*Tibial nerve*- The **tibial nerve** innervates the **plantarflexors** and **invertors** of the foot; injury would present as difficulty standing on the toes (calcaneovalgus deformity), which is opposite to the symptoms described.- Sensory loss from tibial nerve injury involves the **sole of the foot** and is unrelated to the dorsum or upper lateral aspect of the leg.*Deep peroneal nerve*- The **deep peroneal nerve** innervates the dorsiflexors, causing foot drop if injured, but its sensory distribution is limited to the web space between the **first and second toes**.- This isolated injury would not explain the numbness observed over the upper lateral aspect of the leg and the general dorsum of the foot, which is supplied by the superficial peroneal nerve (a branch of the common peroneal nerve).*Femoral nerve*- The **femoral nerve** innervates the **quadriceps muscle** (knee extensors) and provides sensation to the anterior thigh and medial leg via the saphenous nerve.- Injury primarily leads to difficulty with **knee extension** and instability when climbing stairs, not foot drop or numbness in the described lateral distribution.

Q: Injury to which part causes difficulty in dorsiflexion of the foot?

B. ***B*** - This arrow points to the **head and neck of the fibula**. The **common fibular (peroneal) nerve** wraps around the fibular neck, making it susceptible to injury in this location. - Damage to the common fibular nerve results in paralysis of the muscles in the anterior and lateral compartments of the leg, leading to **foot drop**, which is the inability to dorsiflex and evert the foot. *A* - This arrow points to the **medial condyle of the femur**. Injury to this area typically affects the knee joint, potentially damaging ligaments like the MCL or the medial meniscus. - It does not directly involve the nerves responsible for foot dorsiflexion, which are located more laterally and distally. *C* - This arrow indicates the **shaft of the femur**. A fracture of the femoral shaft is a severe injury but does not typically cause isolated difficulty with foot dorsiflexion. - Foot drop could occur if the **sciatic nerve** is injured proximally in the thigh, but this would result in a more widespread neurological deficit affecting both plantarflexion and dorsiflexion. *D* - This arrow points to the **lateral condyle of the femur**. Similar to the medial condyle, an injury here would primarily compromise the structures of the knee joint itself, such as the LCL or lateral meniscus. - The course of the common fibular nerve is posterior to the lateral femoral condyle before it wraps around the fibular neck, so an isolated condylar fracture is unlikely to cause foot drop.

Q: Identify the bone indicated by the arrow in the image.

Navicular. ***Navicular*** - The arrow points to the navicular bone, a key tarsal bone located on the **medial side** of the foot. It articulates proximally with the **talus** and distally with the three **cuneiform** bones. - Its characteristic boat-like shape is identifiable on this AP radiograph, and it serves as the keystone of the **medial longitudinal arch** of the foot. *Cuboid* - The **cuboid** bone is located on the **lateral side** of the foot, articulating proximally with the **calcaneus** and distally with the fourth and fifth metatarsals. The indicated bone is medial. - The cuboid has a more cubical shape, which differentiates it from the scaphoid or boat-like shape of the navicular. *Intermediate cuneiform* - The **intermediate cuneiform** is located **distal** to the navicular bone and proximal to the base of the second metatarsal. The arrow points to a more proximal bone. - It is situated between the medial and lateral cuneiforms, forming part of the transverse arch of the foot. *Lateral cuneiform* - The **lateral cuneiform** is also located **distal** to the navicular, articulating with the third metatarsal. The arrow indicates the bone proximal to the cuneiform row. - It articulates with the intermediate cuneiform medially and the cuboid bone laterally, which is inconsistent with the indicated structure.

Q: A surgical procedure is performed on the great saphenous vein, around 2.5 cm anterior to the medial malleolus. Which of the following structures is most likely to be injured?

Saphenous nerve. ***Saphenous nerve***- The **saphenous nerve**, a terminal cutaneous branch of the femoral nerve, accompanies the **great saphenous vein (GSV)** throughout the length of the leg on the medial side.- It crosses the ankle just anterior to the medial malleolus, lying immediately adjacent to the GSV, making it highly susceptible to injury during surgical procedures like GSV cannulation, harvesting, or varicose vein surgery in this region.*Sural nerve*- The **sural nerve** is located laterally, typically accompanying the **small saphenous vein (SSV)**, and runs behind the **lateral malleolus**.- Therefore, it is anatomically distant from the surgical site located anterior to the medial malleolus.*Deep peroneal nerve*- The **deep peroneal nerve** is located deep within the **anterior compartment** of the leg and supplies the muscles of the anterior compartment.- Although its terminal branches cross the dorsum of the foot, it is not directly associated with the superficial GSV or the medial malleolus in a manner that would predispose it to injury during this specific superficial procedure.*Tibial nerve*- The **tibial nerve** passes through the **tarsal tunnel**, located deep and posterior (behind) the **medial malleolus**.- This nerve supplies the posterior compartment muscles and is deep to the fascia, making it unlikely to be injured during a superficial procedure performed 2.5 cm *anterior* to the medial malleolus.

Q: A patient presented to the OPD with an abnormal gait. On examination, a right-sided hip drop was observed when the patient was asked to stand on the left foot. Which of the following muscles are paralyzed in this patient?

Left gluteus medius and gluteus minimus. ***Left gluteus medius and gluteus minimus*** - The Trendelenburg sign is positive when the pelvis drops on the side opposite the one being stood on (the unsupported side). - This indicates paralysis or weakness of the **hip abductors** on the **standing leg** (left side in this case), which are the gluteus medius and gluteus minimus, responsible for stabilizing the pelvis. - These muscles are innervated by the **superior gluteal nerve**. *Right gluteus maximus and gluteus medius* - Paralysis of muscles on the right side would typically manifest as a deficit when bearing weight on the **right leg** (causing the left hip to drop). - The **gluteus maximus** is mainly a powerful hip extensor (needed for climbing stairs, running, and rising from a seated position) and does not play the primary role in stabilizing the pelvis during single-leg stance. *Right gluteus medius and gluteus minimus* - If these muscles on the right side were paralyzed, the pelvis would drop on the **left side** when the patient attempts to stand on the right foot. - The finding of a right hip drop while standing on the left foot confirms the deficit is on the ipsilateral side of the standing limb (the **left side**). *Left gluteus maximus and gluteus medius* - While the **left gluteus medius** is correctly identified as being paralyzed, the inclusion of the gluteus maximus is inaccurate. - The **gluteus maximus** is innervated by the **inferior gluteal nerve** (not the superior gluteal nerve), and its paralysis causes difficulty with activities requiring hip extension, such as climbing stairs or rising from a chair (gluteus maximus lurch). - The Trendelenburg sign specifically tests the **superior gluteal nerve** and the hip abductors (gluteus medius and minimus), not the gluteus maximus.

Question 1

All of the following veins lack valves except?

Accepted Answer

Femoral vein

Answer

Popliteal vein

Answer

Inferior vena cava (IVC)

Answer

Dural venous sinuses

Question 2

A 27-year-old female wearing high heels sustained an inversion injury at the ankle. Which ligament is most likely to be injured?

Accepted Answer

Anterior talofibular ligament

Answer

Calcaneofibular ligament

Answer

Posterior talofibular ligament

Answer

Deltoid ligament

Question 3

In inversion of the foot, the sole will face:

Accepted Answer

Medially

Answer

Upwards

Answer

Downwards

Answer

Laterally

Question 4

Which of the following muscles acts as the unlocker of the knee?

Accepted Answer

Popliteus

Answer

Gracilis

Answer

Sartorius

Answer

Biceps femoris

Question 5

The artery that is palpated between the medial malleolus and the calcaneal tendon is?

Accepted Answer

Posterior tibial artery

Answer

Popliteal artery

Answer

Anterior tibial artery

Answer

Dorsalis pedis artery

Question 6

A man sustained trauma on the lateral side of his right knee. Two days later, he complains of difficulty in walking, as his toes keep dragging on the ground. He also notices numbness over the upper lateral aspect of the leg and dorsum of the foot. Which nerve is most likely injured?

Accepted Answer

Common peroneal nerve

Answer

Tibial nerve

Answer

Femoral nerve

Answer

Deep peroneal nerve

Question 7

Injury to which part causes difficulty in dorsiflexion of the foot?

Accepted Answer

B

Answer

D

Answer

C

Answer

A

Question 8

Identify the bone indicated by the arrow in the image.

Accepted Answer

Navicular

Answer

Intermediate cuneiform

Answer

Lateral cuneiform

Answer

Cuboid

Question 9

A surgical procedure is performed on the great saphenous vein, around 2.5 cm anterior to the medial malleolus. Which of the following structures is most likely to be injured?

Accepted Answer

Saphenous nerve

Answer

Tibial nerve

Answer

Deep peroneal nerve

Answer

Sural nerve

Question 10

A patient presented to the OPD with an abnormal gait. On examination, a right-sided hip drop was observed when the patient was asked to stand on the left foot. Which of the following muscles are paralyzed in this patient?

Accepted Answer

Left gluteus medius and gluteus minimus

Answer

Right gluteus maximus and gluteus medius

Answer

Right gluteus medius and gluteus minimus

Answer

Left gluteus maximus and gluteus medius

Lower Limb — MCQs

Lower Limb — MCQs

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