Anatomy and Kinesiology Flashcards

During resisted shoulder abduction testing, a client reports weakness but no pain. The therapist suspects impairment of the supraspinatus. Which nerve root level, if compromised, would most specifically disrupt supraspinatus function while sparing the deltoid?

Answer: C5

The supraspinatus is innervated by the suprascapular nerve (C5–C6), but C5 is the dominant root. The deltoid is primarily innervated by the axillary nerve (C5–C6 as well), so complete sparing of the deltoid with supraspinatus weakness points to a lesion affecting the suprascapular nerve specifically at C5, before the axillary branch diverges. C4 innervates more proximal structures; C6 and C7 affect more distal musculature.

The flexor digitorum superficialis and flexor digitorum profundus both cross the wrist and digits. In a position of full wrist flexion, which biomechanical phenomenon most limits the effectiveness of the profundus in producing finger flexion?

Answer: Active insufficiency due to shortened position across two joints

The flexor digitorum profundus crosses the wrist, MCP, PIP, and DIP joints. When the wrist is fully flexed, the muscle is already shortened proximally, limiting its ability to generate further tension distally — this is active insufficiency. The muscle cannot shorten enough across all joints simultaneously to produce strong finger flexion. This is distinct from passive insufficiency, which occurs with lengthening.

A massage therapist is working on a client with anterior pelvic tilt and hyperlordosis. Which combination of findings would be MOST consistent with the upper crossed syndrome pattern as it applies to the lumbopelvic region?

Answer: Tight hip flexors and weak gluteus maximus, tight lumbar erectors and weak abdominals

Vladimir Janda described lower crossed syndrome (not upper) as the pattern seen in anterior pelvic tilt: tight hip flexors (iliopsoas, rectus femoris) paired with weak gluteus maximus and hamstrings, and tight lumbar erectors paired with weak abdominals. The question intentionally names 'upper crossed syndrome as it applies to the lumbopelvic region' — the correct answer reflects lower crossed syndrome characteristics, which is the pattern relevant to hyperlordosis and anterior pelvic tilt.

The close-packed position of the knee joint is characterized by which of the following, and why does it matter clinically for massage therapists?

Answer: Full extension with slight medial tibial rotation; ligaments and capsule are maximally taut, minimizing joint play

The close-packed position of the knee is full extension accompanied by slight medial rotation of the tibia (the 'screw-home mechanism'), during which all ligaments and the joint capsule are maximally taut and joint surfaces are maximally congruent. This position has the least joint play and greatest stability. Clinically, therapists must avoid applying joint mobilization techniques in close-packed position and should recognize this position is where compressive pathology (e.g., meniscal impingement) is most likely to be provoked.

Which of the following correctly distinguishes the roles of the semimembranosus from the biceps femoris long head during gait, particularly at heel strike?

Answer: The semimembranosus internally rotates the tibia during terminal swing; biceps femoris long head externally rotates the tibia, preventing excessive pronation at heel strike

The semimembranosus attaches to the medial condyle of the tibia and, when contracting, internally rotates the tibia relative to the femur (or the femur laterally relative to the tibia in closed chain). The biceps femoris long head attaches to the fibular head and produces external rotation of the tibia. At heel strike, this external rotation assists in supination control of the subtalar joint and helps resist excessive pronation. This rotational differentiation within the hamstring group is an advanced kinesiological concept tested in higher-level certifications.

A client presents with weakness in resisted forearm supination and elbow flexion, diminished brachioradialis reflex, and altered sensation along the lateral forearm. These findings most specifically implicate dysfunction at which level?

Answer: C6 nerve root or the middle trunk of the brachial plexus

C6 innervates the brachioradialis (whose reflex is tested at C6), contributes significantly to supination via the biceps brachii, and provides sensation to the lateral forearm and thumb via the lateral antebrachial cutaneous nerve (a branch of the musculocutaneous nerve, which carries C6). The brachioradialis reflex is the hallmark C6 reflex. C5 would affect the deltoid and biceps reflex more prominently. The radial nerve at the radial tunnel affects finger/wrist extension (posterior interosseous nerve), not supination strength or the brachioradialis reflex in the classic sense. The musculocutaneous nerve alone would affect sensation and biceps/brachialis but not the brachioradialis reflex.