OT Kinesiology 2 — Questions and Answers
Question 1: Which muscle is the primary hip flexor and is commonly assessed in OT when a client has difficulty rising from a chair?
- Gluteus maximus
- Iliopsoas (Correct answer)
- Rectus femoris
- Sartorius
Correct answer: Iliopsoas
The iliopsoas is the primary hip flexor and is critical for the sit-to-stand transfer assessed in OT practice.
Question 2: During forearm supination, which two muscles are primarily responsible for the motion?
- Pronator teres and pronator quadratus
- Supinator and biceps brachii (Correct answer)
- Extensor carpi radialis and brachialis
- Brachioradialis and anconeus
Correct answer: Supinator and biceps brachii
The supinator and biceps brachii are the primary supinators of the forearm, with the biceps being more active against resistance.
Question 3: A client demonstrates a Trendelenburg gait pattern. Which muscle group is most likely weak?
- Hip flexors on the stance limb
- Hip abductors on the stance limb (Correct answer)
- Hip extensors on the swing limb
- Knee extensors on the stance limb
Correct answer: Hip abductors on the stance limb
Weakness of hip abductors (primarily gluteus medius) on the stance limb causes the pelvis to drop on the contralateral side during single-leg stance.
Question 4: What type of muscle contraction occurs in the biceps brachii when slowly lowering a heavy book from a shelf?
- Concentric
- Isometric
- Eccentric (Correct answer)
- Isotonic
Correct answer: Eccentric
Eccentric contraction occurs when the biceps lengthens under tension to control the descent of the weight against gravity.
Question 5: The 'close-packed' position of the glenohumeral joint, which provides maximum bony stability, is:
- 90° abduction with neutral rotation
- Full abduction with external rotation (Correct answer)
- Full flexion with internal rotation
- 0° abduction in anatomical position
Correct answer: Full abduction with external rotation
The glenohumeral joint is in close-packed position at full abduction combined with external rotation, maximizing congruence of joint surfaces.
Question 6: Which nerve innervates the thenar muscles and is most commonly compressed in carpal tunnel syndrome?
- Ulnar nerve
- Radial nerve
- Median nerve (Correct answer)
- Musculocutaneous nerve
Correct answer: Median nerve
The median nerve innervates the thenar muscles (except adductor pollicis) and travels through the carpal tunnel where it is prone to compression.
Question 7: In biomechanics, what is the mechanical advantage (MA) of a second-class lever?
- MA is always less than 1
- MA is always greater than 1 (Correct answer)
- MA equals exactly 1
- MA varies and can be less or greater than 1
Correct answer: MA is always greater than 1
Second-class levers always have the resistance between the fulcrum and effort, resulting in a mechanical advantage greater than 1 (force-efficient).
OT Kinesiology 2
Which muscle is the primary hip flexor and is commonly assessed in OT when a client has difficulty rising from a chair?