Kinesiology and Biomechanics Flashcards

The term 'agonist' in muscle function refers to:

Answer: The primary muscle responsible for producing a movement

The agonist (prime mover) is the muscle primarily responsible for producing the desired movement at a joint.

Scapular winging is most commonly caused by weakness of which muscle?

Answer: Serratus anterior

Serratus anterior weakness allows the medial border of the scapula to lift away from the thoracic wall, producing the characteristic winging appearance.

Which joint in the ankle is primarily responsible for dorsiflexion and plantarflexion?

Answer: Talocrural (tibiotalar) joint

The talocrural (tibiotalar) joint is the true ankle joint and is the primary site for dorsiflexion and plantarflexion movements.

Reciprocal inhibition refers to the phenomenon where:

Answer: Contraction of the agonist causes reflex relaxation of the antagonist

Reciprocal inhibition is a neurological reflex where activation of the agonist causes simultaneous inhibition (relaxation) of the antagonist muscle.

The Q-angle is a clinical measurement relevant to which joint?

Answer: Patellofemoral joint

The Q-angle (quadriceps angle) measures the alignment between the quadriceps pull and the patellar tendon, making it clinically relevant to patellofemoral joint mechanics.

Which type of lever system is found at the ankle during plantarflexion (rising on toes)?

Answer: Second-class lever

Plantarflexion via the calf muscles represents a second-class lever where the load (body weight at the ball of the foot) is between the fulcrum (metatarsal heads) and the effort (Achilles tendon).

Carpal tunnel syndrome most commonly compresses which nerve?

Answer: Median nerve

The median nerve passes through the carpal tunnel and is the nerve most commonly compressed in carpal tunnel syndrome, causing tingling and weakness in the hand.