Kinesiology of the Lower Extremity

Comprehensive practice questions covering the kinesiology and anatomy of the hip, pelvis, knee, ankle, and foot based on lecture notes.

What are the three bones that fuse to form the acetabulum?

The ilium ($40\%$), ischium ($40\%$), and pubis ($20\%$).

What is the normal Angle of Inclination (neck-shaft angle) in an adult femur?

$$125^\circ$$

What condition is characterized by a femoral neck-shaft angle greater than $125^\circ$ or $130^\circ$?

Coxa valga

An angle of torsion greater than normal that may cause 'in-toeing' is known as what?

Anteversion

What is the normal range for the Center Edge Angle (Angle of Wiberg) after age 5?

Angles greater than $25^\circ$ are considered normal; angles less than $20^\circ$ suggest hip dysplasia.

What are the normal Acetabular Anteversion angles?

Between $15^\circ$ and $20^\circ$

Which ligament is known as the 'Y-ligament of Bigelow' and is the strongest in the body?

Iliofemoral ligament

In closed chain positions, what defines the hip's osteokinematic motion?

The concave acetabulum moving on the convex femoral head, resulting in pelvic motion.

Define Nutation in the context of the sacroiliac joint.

Sacral flexion; it occurs when there is anterior rotation of the sacrum in relation to the ilium.

Which muscle is the strongest and most consistent hip flexor?

Iliopsoas

What are the three muscles comprising the Hamstrings?

Biceps Femoris, Semitendinosus, and Semimembranosus.

What is the difference between the Medial and Lateral femoral condyles?

The Medial condyle is larger (average $1.7\,\text{cm}$) and extends more distally; the Lateral condyle juts more anteriorly.

Define 'Patella alta' and 'Patella baja'.

Patella alta is when the patella lies more superiorly on the femur; Patella baja is when it lies more distally.

What is the patellar loading force during squatting?

$7$ times the body weight.

What are the normal values for the Tibiofemoral angle in an adult?

$170^\circ$ to $175^\circ$, resulting in approximately $6^\circ$ of valgus.

What is the primary function of the Anterior Cruciate Ligament (ACL)?

Prevents anterior subluxation of the tibia on the femur (OKC) and checks extension/hyperextension of the knee.

Describe the shapes of the Medial and Lateral Menisci.

The Medial Meniscus is nearly semicircular (C-shaped), while the Lateral Meniscus is nearly circular (O-shaped).

What is the 'Screw-Home Mechanism' of the knee?

The terminal rotation that occurs during the final $20^\circ$ of knee extension to lock the joint; in OKC, the tibia laterally rotates.

What is the normal Q-angle range for men and women?

Men: $10^\circ$ to $14^\circ$; Women: $15^\circ$ to less than $23^\circ$.

Which muscle is responsible for 'unlocking' the screw home mechanism?

Popliteus

What percentage of body weight do the Tibia and Fibula each carry?

Tibia carries $90\%$; Fibula carries $10\%$.

What are the three regions of the foot?

Hind-foot (talus and calcaneus), Mid-foot (navicular, cuboid, and cuneiforms), and Fore-foot (metatarsals and phalanges).

What is the keystone of the Medial Longitudinal Arch?

The head of the talus.

During ankle dorsiflexion, how does the fibula move?

The fibula glides superiorly and rotates externally (laterally).

Which ligament is the first to be torn in a typical lateral ankle sprain?

Anterior Talofibular Ligament (ATFL).

What is another name for the Midtarsal Joint?

Chopart’s Joint

What is the 'sustentaculum tali'?

A horizontal shelf arising from the anteromedial portion of the calcaneus.

Which joint is formed between the tarsals and metatarsals?

Tarsometatarsal Joint (Lisfranc's Joint).

What muscles are included in the 'Pretibial' or anterior group of the leg?

Tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius.