Take a complex action like riding a bike: your qaudriceps and calf muscles are the agonists (contracting muscles). The antagonists are the muscles of your hamstring and shins. other leg muscles act as synergists and muscles of your back and abdomen act as fixators to stop you falling off.
water
Fixator
The fixator is one of many muscles used during situps. The fixator muscle stabilizes one part of your body when you move another part.
Synergists as well as fixator muscles.
The functions of a fixator muscle is the stabalizing of the orgin of the prime mover so that the prime mover can act more efficiently. Fixators steady the proximal end of a limb while movements occurs at the distal end. EX: The scapula is a freely movable bone that serves as the orgin for several muscles that move the arm. When the arm contracts the scapula must be held steady.
fixator
Gluteus Maximus
its either agonists, antagonists, synergists, or a fixator. i know this may not help if you are doing the worksheet from Dr. Adcocks lab but hopefully these narrow it down to four for some people (-:
muscles
All muscles are red because they all have blood in them.
Gluteus maximus
Fixator