Kinesiology and Biomechanics Flashcards

Which muscle acts as the primary synergist to the gluteus maximus during hip extension?

Answer: Biceps femoris

The biceps femoris (long head) assists the gluteus maximus as a synergist in hip extension.

When the scapula moves away from the spine, this motion is called:

Answer: Protraction

Protraction (abduction) of the scapula is movement away from the vertebral column, performed primarily by the serratus anterior.

A client has weak hip abductors. Which gait deviation would you expect?

Answer: Trendelenburg gait

Trendelenburg gait occurs when weak hip abductors (primarily gluteus medius) fail to stabilize the pelvis during single-leg stance, causing the contralateral hip to drop.

The term 'closed kinetic chain' refers to movement where:

Answer: The distal segment is fixed and the proximal segment moves

In a closed kinetic chain, the distal segment (such as the foot) is fixed to a surface, causing the proximal segments to move.

Which type of muscle contraction produces the greatest force?

Answer: Eccentric

Eccentric contractions, where the muscle lengthens under load, produce greater force than both concentric and isometric contractions.

The line of gravity falls anterior to which lumbar vertebral segment in normal standing posture?

Answer: L3

In standard anatomical posture, the line of gravity passes anterior to the lumbar spine at approximately the L3 level.

Which motion occurs at the subtalar joint that allows the foot to adapt to uneven terrain?

Answer: Inversion and eversion

The subtalar (talocalcaneal) joint primarily allows inversion and eversion, enabling the foot to adapt to uneven ground surfaces.