Human Anatomy & Physiology Flashcards

Which muscle is the primary plantarflexor during the push-off (terminal stance and pre-swing) phase of the gait cycle?

Answer: Gastrocnemius-soleus complex

The gastrocnemius-soleus complex generates the majority of propulsive power during push-off through concentric plantarflexion.

The pes cavus foot type is characterized by an abnormally high medial arch and often presents with which associated toe deformity?

Answer: Hammer toe or claw toe deformity

Pes cavus causes intrinsic muscle imbalance leading to clawing of the lesser toes (MTP hyperextension and IP flexion) due to extensor substitution.

In the elbow, which anatomical structure is at greatest risk during a valgus extension overload mechanism, common in overhead throwing athletes?

Answer: Ulnar collateral ligament (UCL)

The ulnar collateral ligament (specifically the anterior bundle) is the primary restraint to valgus stress and is the most commonly injured structure in overhead throwing athletes.

The center of pressure (COP) during quiet standing normally falls within which anatomical region of the foot?

Answer: Slightly anterior to the ankle joint between the heel and midfoot

During quiet standing the COP typically rests slightly anterior to the ankle joint axis, approximately one-third of the foot length from the heel, requiring ongoing muscular balance.

Which bone of the foot is described as the 'keystone' of the lateral longitudinal arch?

Answer: Cuboid

The cuboid bone is considered the keystone of the lateral longitudinal arch, wedging between the calcaneus and the 4th-5th metatarsals.

A patient with C6 spinal cord injury would retain which functional movement critical for upper extremity orthotic consideration?

Answer: Wrist extension via extensor carpi radialis

C6 SCI preserves wrist extension (ECRL/ECRB) which enables tenodesis grasp, a critical functional pattern for hand orthotic design.

Charcot neuroarthropathy most commonly affects which joints of the foot in diabetic patients?

Answer: Tarsometatarsal (Lisfranc) and midtarsal joints

The tarsometatarsal (Lisfranc) and midtarsal joints are the most common sites of Charcot neuroarthropathy in diabetic patients, causing rocker-bottom deformity.