COKO COKO Anatomy and Biomechanics 2

Question 1

The rotator cuff is composed of which four muscles?

Accepted Answer

Supraspinatus, infraspinatus, teres minor, subscapularis

Answer

The rotator cuff (SITS muscles) — supraspinatus, infraspinatus, teres minor, and subscapularis — stabilize the glenohumeral joint by compressing the humeral head into the glenoid.

Question 2

In biomechanics, the 'lever arm' (moment arm) is defined as:

Accepted Answer

The perpendicular distance from the axis of rotation to the line of force application

Answer

The moment arm is the perpendicular distance between the joint axis and the force vector, determining the torque produced by a muscle or external load.

Question 3

Which type of muscle contraction occurs when the muscle produces force while lengthening?

Accepted Answer

Eccentric contraction

Answer

Eccentric contractions occur when a muscle generates force while being elongated, such as the quadriceps controlling descent during a squat.

Question 4

The lumbar spine's natural curvature is called:

Accepted Answer

Lordosis

Answer

Lordosis is the normal inward (anterior) curvature of the lumbar spine; excessive lordosis is termed hyperlordosis and can contribute to low back pain.

Question 5

Which muscle is primarily responsible for dorsiflexion of the ankle?

Accepted Answer

Tibialis anterior

Answer

The tibialis anterior, located on the anterolateral shin, is the primary dorsiflexor of the ankle, pulling the foot upward toward the shin.

(COKO) College of Kinesiologists of Ontario Practice Test

(COKO) College of Kinesiologists of Ontario Practice Test

COKO COKO Anatomy and Biomechanics 2