NCBTMB Kinesiology and Biomechanics 3 — Questions and Answers
Question 1: Which rotator cuff muscle is most commonly involved in impingement syndrome?
- Infraspinatus
- Teres minor
- Subscapularis
- Supraspinatus (Correct answer)
Correct answer: Supraspinatus
The supraspinatus tendon is most frequently impinged under the coracoacromial arch, making it the most common rotator cuff muscle involved in shoulder impingement.
Question 2: A force couple at the shoulder girdle involves coordinated action between the upper trapezius, lower trapezius, and:
- Rhomboids
- Serratus anterior (Correct answer)
- Pectoralis minor
- Levator scapulae
Correct answer: Serratus anterior
The serratus anterior works with the upper and lower trapezius to create upward rotation of the scapula through a force couple mechanism.
Question 3: The center of gravity in the adult human body is typically located:
- At the level of the navel
- Anterior to the S2 vertebra (Correct answer)
- At the xiphoid process
- Posterior to the L4 vertebra
Correct answer: Anterior to the S2 vertebra
The center of gravity in adults is typically located just anterior to the second sacral segment (S2), within the pelvis.
Question 4: Which plane of motion does lumbar lateral flexion occur in?
- Sagittal plane
- Frontal (coronal) plane (Correct answer)
- Transverse plane
- Oblique plane
Correct answer: Frontal (coronal) plane
Lateral flexion of the lumbar spine occurs in the frontal (coronal) plane around an anterior-posterior axis.
Question 5: Which muscle is the primary wrist flexor and also contributes to forearm pronation?
- Flexor carpi ulnaris
- Palmaris longus
- Flexor carpi radialis (Correct answer)
- Pronator teres
Correct answer: Flexor carpi radialis
The flexor carpi radialis is the primary wrist flexor and also assists in forearm pronation due to its distal attachment on the radial side.
Question 6: During the gait cycle, heel strike to foot flat is part of which phase?
- Swing phase
- Push-off phase
- Loading response (stance phase) (Correct answer)
- Pre-swing phase
Correct answer: Loading response (stance phase)
Heel strike to foot flat represents the loading response, which is the initial portion of the stance phase in the gait cycle.
Question 7: A client demonstrates excessive lumbar lordosis. Which muscle group is most likely shortened/overactive?
- Abdominals
- Gluteus maximus
- Hip flexors (iliopsoas) (Correct answer)
- Hamstrings
Correct answer: Hip flexors (iliopsoas)
Tight or overactive hip flexors, particularly the iliopsoas, anteriorly tilt the pelvis, increasing lumbar lordosis.
NCBTMB Kinesiology and Biomechanics 3
Which rotator cuff muscle is most commonly involved in impingement syndrome?