When you bring your hand to your shoulder, your biceps muscle ____ and your triceps muscle ____.
A) contracts; relaxes
B) relaxes; contracts
C) contracts; contracts
D) relaxes; relaxes
E) lengthens; shortens

Question

​When you bring your hand to your shoulder, your biceps muscle ____ and your triceps muscle ____.
A) ​contracts; relaxes
B) ​relaxes; contracts
C) ​contracts; contracts
D) ​relaxes; relaxes
E) ​lengthens; shortens

Quizplus · Accepted Answer

When you bring your hand to your shoulder, your biceps muscle contracts to facilitate the movement, while your triceps muscle relaxes to allow the motion. This is because the biceps and triceps work antagonistically; when one contracts, the other relaxes.

​When You Bring Your Hand to Your Shoulder, Your Biceps

When You Bring Your Hand to Your Shoulder, Your Biceps