Lower Limb Practice Questions

Q: Main blood supply to the head and neck of femur comes from

Medial circumflex femoral artery. ***Medial circumflex femoral artery*** - The **medial circumflex femoral artery** is the primary arterial supply to the **head and neck of the femur**, particularly via its **retinacular branches**. - These branches ascend along the femoral neck within the joint capsule, supplying most of the femoral head. *Lateral circumflex femoral artery* - The **lateral circumflex femoral artery** primarily supplies the muscles of the **anterior compartment of the thigh**, including the quadriceps femoris. - While it contributes to anastomoses around the hip, its direct supply to the femoral head and neck is less significant than the medial circumflex. *Artery of ligamentum teres* - The **artery of the ligamentum teres** (foveal artery) supplies a small, variable portion of the **femoral head**, mainly in children. - Its contribution to the overall blood supply to the adult femoral head and neck is often negligible or absent. *Popliteal artery* - The **popliteal artery** is located in the **popliteal fossa** behind the knee joint and is the continuation of the femoral artery. - Its branches supply the structures around the knee and lower leg, not the femoral head and neck.

Q: Which muscles are known as 'Triceps surae'?

Gastro-soleus. ***Gastro-soleus*** - The **Triceps surae** refers to the two heads of the **gastrocnemius muscle** and the **soleus muscle**, which together form the powerful calf muscle. - These three muscles converge to form the **Achilles tendon** (calcaneal tendon) and are prime movers for **plantarflexion** of the ankle. *Popliteus* - The popliteus muscle is located behind the knee joint and acts to **unlock the knee** during flexion. - It does not contribute to the bulk of the calf and is not part of the Triceps surae group. *Extensor hallucis longus* - This muscle is located in the **anterior compartment** of the leg and is responsible for **dorsiflexion** of the ankle and extension of the great toe. - It is an antagonist to the Triceps surae, which primarily performs plantarflexion. *Extensor digitorum longus* - The extensor digitorum longus is also in the **anterior compartment** of the leg, responsible for **dorsiflexion** of the ankle and extension of the lateral four toes. - It is functionally opposite to the actions of the Triceps surae and in a different muscle compartment.

Q: Which of the following statements about the linea aspera is correct?

Continues as gluteal tuberosity. Correct: Continues as gluteal tuberosity - The lateral lip of the linea aspera continues superiorly as the gluteal tuberosity (also called the gluteal ridge or line) - This anatomical continuation is a key feature of the femur's posterior surface - The gluteal tuberosity serves as the attachment site for the gluteus maximus muscle - The medial lip continues superiorly as the pectineal line (spiral line), which then joins the lesser trochanter Incorrect: Forms lateral border of femur - The linea aspera is located on the posterior surface of the femoral shaft, not on the lateral border - The lateral border of the femur is formed by the smooth lateral surface of the shaft - The linea aspera's lateral lip is a posterior ridge, distinct from the true lateral border Incorrect: Forms medial border of femur - The linea aspera is on the posterior aspect of the femur, not the medial border - The medial border of the femur is formed by the smooth medial surface of the shaft - The medial lip of the linea aspera is a muscle attachment site on the posterior surface, not a border

Q: Which arteries supply the talus?

All of the options. ***All of the options*** - The **talus** has a tenuous blood supply due to its limited muscular attachments, receiving contributions from multiple surrounding arteries to ensure adequate perfusion. - The **anterior tibial artery**, **posterior tibial artery**, and **peroneal artery** all contribute branches that form an anastomotic network around the talus. *Anterior tibial artery* - The **anterior tibial artery** contributes blood supply to the talus primarily through its **dorsal pedis branch** and ascending branches that supply the neck and head of the talus. - Its major role is in supplying the **anterior and superior talar surfaces**. *Posterior tibial artery* - The **posterior tibial artery** is a significant source of blood supply, particularly to the body and posterior aspect of the talus, via branches like the **artery of the tarsal canal** and the **deltoid branch**. - Its branches contribute to the **posterior talar artery network** which is crucial for the central part of the talus. *Peroneal artery* - The **peroneal artery** provides blood supply to the lateral and posterior parts of the talus through its **communicating branch** and perforating branches. - It contributes to the **tarsal artery network**, ensuring collateral circulation to the talus.

Q: Crural index is:

Length of tibia/femur x 100. ***Length of tibia/femur x 100*** - The **crural index** is a measure used in physical anthropology and comparative anatomy to describe the proportion of the lower leg to the thigh. - It is calculated by dividing the **length of the tibia** (lower leg bone) by the **length of the femur** (thigh bone) and multiplying by 100 to express it as a percentage. *Length of radius/humerus x 100* - This formula describes the **brachial index**, which measures the proportion of the forearm to the upper arm. - It does not represent the crural index, which refers specifically to the **lower limb**. *Length of fibula/tibia x 100* - This ratio compares the two bones within the lower leg but is not the definition of the **crural index**. - The crural index focuses on the relative length of the lower leg to the entire thigh, reflecting overall **limb proportions**. *Length of radius/ulna x 100* - This ratio compares the lengths of the two bones in the forearm and does not correspond to the **crural index**. - The crural index involves the **tibia** and **femur**, which are bones of the lower limb.

Q: What is the preferred site for intramuscular injection in the gluteus muscle?

Superolateral. ***Superolateral*** - This quadrant is preferred because it avoids the **sciatic nerve** and major **blood vessels**, minimizing the risk of injury. - The muscle mass in this region, primarily the **gluteus medius**, is sufficient for medication absorption. *Inferomedial* - This area carries a high risk of damaging the **sciatic nerve**, which runs through the lower, medial part of the gluteus. - Injecting here can also hit major **blood vessels**, leading to bleeding or hematoma. *Superomedial* - While somewhat safer than the inferomedial quadrant, this area is still closer to the **sciatic nerve** exit point and major vessels compared to the superolateral region. - The muscle bulk is also less prominent here compared to the superolateral aspect. *Inferolateral* - This quadrant is still in the vicinity of the **sciatic nerve** and major blood vessels, making it riskier than the superolateral site. - There is less muscle mass here compared to the superior quadrants, which can lead to improper drug absorption.

Q: Which of the following statements about the popliteus muscle is the most incorrect?

Causes locking of knee. ***Causes locking of knee*** - The popliteus muscle is classically known as the **"key to the locked knee"** because it **unlocks** the fully extended knee joint, not locks it. - It initiates flexion by **medially rotating the tibia on the femur** (or laterally rotating the femur on the tibia in a closed chain). - This is the **opposite of what the statement claims**, making it the most fundamentally incorrect statement about popliteus function. - This represents a complete reversal of the muscle's primary and most distinctive action. *Innervated by the common peroneal nerve* - The popliteus muscle is innervated by the **tibial nerve** (nerve to popliteus, L4-S1), not the common peroneal nerve. - While this is anatomically incorrect, it is a specific detail error rather than a complete functional reversal. *Flexor of knee* - The popliteus does act as a **weak flexor of the knee joint**, particularly when the knee is partially flexed. - This statement is correct. *Originates from the lateral condyle of the femur* - The popliteus originates from the **lateral surface of the lateral femoral condyle** and the lateral meniscus. - This statement is anatomically correct.

Q: The nutrient artery to the femur is?

Profunda femoris artery. ***Profunda femoris artery*** - The **profunda femoris artery** (deep femoral artery) is the main blood supply to the **femur's diaphysis** via its perforating branches. - Typically, the **second perforating branch** gives rise to the nutrient artery, which enters the bone through the **nutrient foramen** in the middle third of the femoral shaft. *Femoral artery* - The **femoral artery** is the main artery of the thigh and gives off several branches, including the profunda femoris artery. - While it is the source of blood for the entire lower limb, it does not directly give rise to the main **nutrient artery of the femur**. *Popliteal artery* - The **popliteal artery** is a continuation of the femoral artery in the popliteal fossa behind the knee. - It primarily supplies structures around the knee joint and the lower leg, not the direct **diaphyseal nutrient supply** to the femur. *Medial circumflex femoral artery* - The **medial circumflex femoral artery** primarily supplies the head and neck of the femur, crucial for its vascularity, especially in children. - It does not serve as the **main nutrient artery** for the femoral shaft (diaphysis).

Q: What is the consequence of tibial nerve injury/palsy?

Loss of plantar flexion. **Loss of plantar flexion** - The **tibial nerve** innervates the muscles of the **posterior compartment of the leg**, which are primarily responsible for **plantar flexion** of the foot. - Injury to this nerve directly impairs the function of muscles like the gastrocnemius, soleus, and tibialis posterior, leading to a significant loss of the ability to point the foot downwards. *Dorsiflexion of foot at ankle joint* - **Dorsiflexion** is primarily mediated by muscles in the **anterior compartment of the leg**, such as the tibialis anterior, which are innervated by the **deep fibular nerve**. - Tibial nerve injury would not directly affect these muscles or their function; rather, it leads to issues with the opposing action. *Loss of sensation of dorsum of foot* - Sensation to the **dorsum of the foot** is primarily supplied by the **superficial fibular nerve** (for most of the dorsum) and the **deep fibular nerve** (for the first web space). - While the tibial nerve provides sensation to the sole of the foot, it does not typically innervate the dorsum. *Paralysis of muscles of anterior compartment of leg* - The muscles of the **anterior compartment of the leg** (e.g., tibialis anterior, extensor digitorum longus, extensor hallucis longus) are innervated by the **deep fibular nerve**. - A tibial nerve injury would paralyze muscles in the posterior compartment, not the anterior compartment.

Q: In walking, gravity tends to tilt pelvis and trunk to the unsupported side, the major factor in preventing this unwanted movement is?

Gluteus medius and minimus. ***Gluteus medius and minimus*** - The **gluteus medius** and **gluteus minimus** are essential **abductors** of the hip, primarily responsible for stabilizing the pelvis during the **single-limb support phase of gait**. - When one leg is lifted during walking, these muscles on the **stance leg side** contract to prevent the pelvis from tilting downwards on the unsupported swing leg side. *Adductor muscles* - **Adductor muscles** (adductor longus, brevis, magnus, pectineus, gracilis) primarily function to bring the thigh toward the midline of the body. - While they play a role in gait stability, their main action is not to prevent the lateral pelvic tilt described. *Quadriceps* - The quadriceps femoris group (rectus femoris, vastus lateralis, medialis, intermedius) are powerful **extensors of the knee**. - They are crucial for weight acceptance and propulsion during walking but do not directly prevent lateral pelvic tilt [1]. *Gluteus maximus* - The **gluteus maximus** is the largest and most powerful muscle of the hip, primarily responsible for **hip extension** and **external rotation**. - It is crucial for activities like climbing stairs or running, but its main role in normal walking is not to prevent lateral pelvic tilt; that function is more specific to the gluteus medius and minimus.

Question 1

Main blood supply to the head and neck of femur comes from

Accepted Answer

Medial circumflex femoral artery

Answer

Lateral circumflex femoral artery

Answer

Artery of ligamentum teres

Answer

Popliteal artery

Question 2

Which muscles are known as 'Triceps surae'?

Accepted Answer

Gastro-soleus

Answer

Popliteus

Answer

Extensor hallucis longus

Answer

Extensor digitorum longus

Question 3

Which of the following statements about the linea aspera is correct?

Accepted Answer

Continues as gluteal tuberosity

Answer

Forms lateral border of femur

Answer

Forms medial border of femur

Answer

None of the options

Question 4

Which arteries supply the talus?

Accepted Answer

All of the options

Answer

Peroneal artery

Answer

Posterior tibial artery

Answer

Anterior tibial artery

Question 5

Crural index is:

Accepted Answer

Length of tibia/femur x 100

Answer

Length of radius/humerus x 100

Answer

Length of fibula/tibia x 100

Answer

Length of radius/ulna x 100

Question 6

What is the preferred site for intramuscular injection in the gluteus muscle?

Accepted Answer

Superolateral

Answer

Inferolateral

Answer

Superomedial

Answer

Inferomedial

Question 7

Which of the following statements about the popliteus muscle is the most incorrect?

Accepted Answer

Causes locking of knee

Answer

Originates from the lateral condyle of the femur

Answer

Flexor of knee.

Answer

Innervated by the common peroneal nerve.

Question 8

The nutrient artery to the femur is?

Accepted Answer

Profunda femoris artery

Answer

Femoral artery

Answer

Popliteal artery

Answer

Medial circumflex femoral artery

Question 9

What is the consequence of tibial nerve injury/palsy?

Accepted Answer

Loss of plantar flexion

Answer

Dorsiflexion of foot at ankle joint

Answer

Loss of sensation of dorsum of foot

Answer

Paralysis of muscles of anterior compartment of leg

Question 10

In walking, gravity tends to tilt pelvis and trunk to the unsupported side, the major factor in preventing this unwanted movement is?

Accepted Answer

Gluteus medius and minimus

Answer

Adductor muscles

Answer

Quadriceps

Answer

Gluteus maximus

Lower Limb — MCQs

Lower Limb — MCQs

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