Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.

Proprioceptive neuromuscular facilitation (PNF) is a form of assisted stretching. It combines passive stretching with muscle contraction. First, your partner applies force to stretch your muscle ...

The flow of water within a muscle fiber may dictate how quickly muscle can contract, according to a new study. The flow of water within a muscle fiber may dictate how quickly muscle can contract, ...

The calf muscles, comprising the gastrocnemius and soleus, are often referred to as the body’s “second heart” because of their critical role in promoting blood circulation. Every time we walk, stand, ...

MIT scientists find that motor neuron growth increased significantly over 5 days in response to biochemical (left) and mechanical (right) signals related to exercise. The green ball represents cluster ...