Muscular contraction and Muscle spasm

Muscular contraction noun - Physiology) a shortening or tensing of a part or organ (especially of a muscle or muscle fiber.

Muscle spasm and muscular contraction are semantically related. In some cases you can use "Muscle spasm" instead a noun phrase "Muscular contraction".

Muscle spasm noun - A painful and involuntary muscular contraction.

Muscular contraction and muscle spasm are semantically related. You can use "Muscular contraction" instead a noun phrase "Muscle spasm".