Applied Science and Anatomy Flashcards

A client presents with weakness in shoulder abduction beyond 90°, numbness along the lateral arm, and an absent biceps reflex. Which nerve root is most likely compromised?

Answer: C6

C6 radiculopathy produces weakness in shoulder abduction (especially above 90°), lateral forearm and thumb numbness, and a diminished or absent biceps reflex. C5 affects the biceps reflex as well but presents with deltoid weakness and lateral arm numbness without thumb involvement. C7 loss affects the triceps reflex and wrist extension. C8 affects grip and finger flexion with ulnar-side numbness.

During effleurage to the posterior thigh, a therapist notices the client's hamstrings reflexively contract when pressure is applied near the ischial tuberosity. This is MOST likely due to activation of which receptor type?

Answer: Muscle spindle intrafusal fibers

Muscle spindle intrafusal fibers detect changes in muscle length and rate of change. Sustained deep pressure near the proximal hamstring can stretch the muscle spindle, triggering a stretch reflex (myotatic reflex) mediated by Ia afferents, causing reflexive contraction. Golgi tendon organs respond to tension and cause inhibition (inverse myotatic reflex). Ruffini endings and Pacinian corpuscles are cutaneous mechanoreceptors involved in pressure and vibration detection, not stretch reflexes.

A massage therapist is working on a client who had a lumbar laminectomy at L4–L5 six months ago. The client reports new-onset foot drop. Which muscle is MOST directly affected?

Answer: Tibialis anterior

Foot drop (inability to dorsiflex the ankle) is primarily caused by weakness of the tibialis anterior, the prime mover of dorsiflexion, innervated by the deep peroneal nerve (L4–L5). A laminectomy at L4–L5 can compromise the L4 or L5 nerve roots. While the extensor hallucis longus (L5) also contributes to dorsiflexion, tibialis anterior is the primary muscle responsible for the gait-phase dorsiflexion that prevents foot drop.

Which of the following accurately describes the fascial relationship between the thoracolumbar fascia (TLF) and core stability during massage assessment?

Answer: The TLF transmits tension from the latissimus dorsi to the contralateral gluteus maximus via the posterior layer, creating a cross-body stabilization mechanism

The posterior layer of the thoracolumbar fascia receives tensile input from the latissimus dorsi on one side and the contralateral gluteus maximus via the sacrotuberous ligament complex, forming a functional 'posterior oblique sling.' This myofascial force transmission is central to lumbar stabilization during gait and lifting. Understanding this cross-body fascial continuity is essential for evaluating core dysfunction in massage clients.

A client with Raynaud's phenomenon asks about the physiological basis of their condition. Which mechanism BEST explains the pathophysiology relevant to a massage therapist's assessment?

Answer: Exaggerated sympathetic vasoconstriction of digital arterioles in response to cold or emotional stress

Raynaud's phenomenon results from an exaggerated sympathetic nervous system response that causes intense vasospasm of digital arterioles, typically triggered by cold or emotional stress. The classic triphasic color change (white → blue → red) reflects ischemia, cyanosis, and reactive hyperemia. This is critical for massage therapists because direct cold application, vigorous compression to the digits, or emotional distress during a session can precipitate an episode. Treatment rooms should be warm and techniques should be gentle and non-provocative.

When performing deep transverse friction to the common extensor tendon at the lateral epicondyle, which tissue property is the therapist PRIMARILY exploiting to remodel fibrotic collagen?

Answer: Mechanotransduction stimulating fibroblast synthesis of type I collagen along lines of stress

Deep transverse friction (Cyriax method) works via mechanotransduction — the conversion of mechanical signals into cellular responses. Repetitive controlled micro-stress across the collagen fibers stimulates fibroblasts to synthesize and align new type I collagen along lines of mechanical stress, replacing disorganized scar tissue with properly oriented collagen. Thixotropy describes a gel-to-sol reversible change in ground substance and is associated with broader myofascial techniques, not tendon remodeling. The piezoelectric effect is relevant to bone adaptation, not soft tissue. Histamine release occurs with injury but does not directly drive collagen remodeling.