The prime mover for trunk flexion when doing a sit-up is the
A) rectus abdominis.
B) erector spinae.
C) splenius capitis.
D) splenius cervicis.

Question

Quizplus · Accepted Answer

The rectus abdominis is the primary muscle responsible for trunk flexion in a sit-up. The erector spinae, on the other hand, is responsible for trunk extension and would not be engaged during a sit-up. The splenius capitis and cervicis are muscles of the neck and would not be involved in sit-up movements.

The Prime Mover for Trunk Flexion When Doing a Sit-Up