Rachel Tavel is a doctor of physical therapy, certified strength and conditioning specialist and writer. She works as a physical therapist in an outpatient orthopedic physical therapy setting and as a ...

Muscle cramps are a common issue that many people get from time to time. If one of your muscles feels like it’s contracting (getting tight) for no reason — and you can’t get it to relax — that’s a ...

Muscle knots are highly irritated muscle fibers that have tightened into a ball in one area of your muscle. These painful, tender spots can feel sore and often occur in your upper back, shoulders, or ...

The muscular system works to control the movement of our body and internal organs. Muscle tissue contains something called muscle fibers. Muscle fibers consist of a single muscle cell. They help to ...