a vascular spasm
When the bicep contracts the triceps relax
When one muscle in a pair contracts the other expands.
Points The toes
when a muscle cramps
relax
it contracts
When the muscle contracts, the tendon pulls on the bone to create movement. The tendon is the connective tissue that attaches the muscle to the bone, so when the muscle contracts, it exerts force on the tendon, which in turn moves the bone.
Isotonic contractions. This happens when the muscle shortens as it contracts
depends on which muscle but the opposite muscle sometimes contracts aswell to stabalize the joint some relaxes ...
when the muscle shortens (contracts), the two bones come closer together, isometric contraction excepted.
The muscle in your arm contracts. The muscle on the other side of your arm, opposite from the side that you are flexing, stretches.