A "fixator" is a medical device used to stabilize and support broken bones or joints during the healing process. It helps to keep the bones in place and promote proper alignment for proper healing. Full definition
External fixators consist of pins drilled through the skin and bone and are held together by a stainless steel clamp outside the body. (texaswestveterinarian.com)
Veterinary surgeons will commonly use circular external skeletal fixators in conjunction with small diameter fixation wires placed under tension. (arkansasveterinarysurgerycenter.com)
The overhead press also bring legs into play to stabilise the movement along with abs and back — these all work as fixator muscles. (mystrengthtraining.com)