OCS OCS Biomechanics & Kinesiology 1 — Questions and Answers
Question 1: Which type of joint motion describes the rolling and gliding of one joint surface on another, as occurs at the knee during flexion?
- Arthrokinematics (Correct answer)
- Osteokinematics
- Accessory motion
- Passive range of motion
Correct answer: Arthrokinematics
Arthrokinematics refers to the motion of joint surfaces relative to each other, including rolling, gliding, and spinning.
Question 2: The Q-angle is measured between the line of pull of the quadriceps and the patellar tendon; an abnormally increased Q-angle is most associated with which condition?
- Patellofemoral pain syndrome (Correct answer)
- Iliotibial band syndrome
- Pes anserinus bursitis
- Patellar tendinopathy
Correct answer: Patellofemoral pain syndrome
An increased Q-angle increases lateral patellar tracking forces, predisposing individuals to patellofemoral pain syndrome.
Question 3: During normal gait, which phase is characterized by maximal single-limb support and the greatest demand on the hip abductors?
- Mid-stance (Correct answer)
- Terminal swing
- Loading response
- Pre-swing
Correct answer: Mid-stance
During mid-stance, the hip abductors (primarily gluteus medius) must generate sufficient force to prevent contralateral pelvic drop (Trendelenburg sign).
Question 4: The close-packed position of the glenohumeral joint, where the joint is most congruent and the capsule is most taut, is:
- Full abduction and external rotation (Correct answer)
- 90° abduction and neutral rotation
- Full flexion
- Anatomical position
Correct answer: Full abduction and external rotation
Full abduction combined with external rotation places the glenohumeral joint in its close-packed position with maximum capsular tension and bony congruence.
Question 5: The scapulohumeral rhythm describes coordinated movement between the glenohumeral and scapulothoracic joints; what is the typical ratio of glenohumeral to scapulothoracic motion during shoulder abduction?
- 2:1 (Correct answer)
- 1:1
- 3:1
- 1:2
Correct answer: 2:1
The classic scapulohumeral rhythm is approximately 2:1, meaning for every 3° of shoulder abduction, 2° occur at the glenohumeral joint and 1° at the scapulothoracic joint.
Question 6: Which muscle is the primary contributor to dynamic lumbar stabilization through its role as a local stabilizer of the lumbar spine?
- Transverse abdominis (Correct answer)
- Rectus abdominis
- External oblique
- Iliopsoas
Correct answer: Transverse abdominis
The transverse abdominis is a deep local stabilizer that creates intra-abdominal pressure and increases tension in the thoracolumbar fascia to stabilize the lumbar spine.
OCS OCS Biomechanics & Kinesiology 1
Which type of joint motion describes the rolling and gliding of one joint surface on another, as occurs at the knee during flexion?