Musculoskeletal Anatomy & Pathophysiology Flashcards

The 'close-packed position' of a synovial joint is defined as the position of:

Answer: Maximum congruence, ligamentous tension, and minimal joint play

The close-packed position maximizes congruence of articular surfaces and tension in ligaments, making it the most stable but least mobilizable position.

Which structure is damaged in a 'SLAP' lesion of the shoulder?

Answer: Superior labrum at the biceps anchor

SLAP (Superior Labrum Anterior to Posterior) tears involve the superior glenoid labrum at the long head biceps attachment.

Pronation of the subtalar joint is a combination of which three motions?

Answer: Dorsiflexion, eversion, and abduction

Subtalar pronation combines calcaneal eversion, talar plantarflexion/adduction, resulting in foot dorsiflexion, eversion, and abduction.

The sciatic nerve is formed from which spinal nerve roots?

Answer: L4–S3

The sciatic nerve arises from the lumbosacral plexus (L4–S3) and is the largest nerve in the body.

Which type of muscle fiber has the highest oxidative capacity and greatest resistance to fatigue?

Answer: Type I (slow-twitch oxidative)

Type I fibers have abundant mitochondria and myoglobin, making them highly oxidative and fatigue-resistant for sustained postural activity.

Adhesive capsulitis (frozen shoulder) is characterized by fibrosis and contracture primarily of which structure?

Answer: Joint capsule and coracohumeral ligament

Adhesive capsulitis involves diffuse fibrosis of the glenohumeral joint capsule and coracohumeral ligament, severely restricting external rotation and elevation.

During normal gait, which muscle group eccentrically controls knee flexion during the loading response (weight acceptance)?

Answer: Quadriceps

The quadriceps eccentrically contract to control the degree of knee flexion (loading response flexion ~15–20°) after heel strike to prevent collapse.