What's actually happening when you pull, sprain, or rupture a muscle

Here's what actually happens when you "pull" a muscle.

The human body has three types of muscles skeletal, cardiac and visceral. But we can only control, and damage, our skeletal muscles.

These are made of thousands of vulnerable muscle fibers. Awkward movements or overexertion can tear some, or all, of them.

If 5% of the fibers are torn, it pulls the muscle. You'll feel an uncomfortable twinge and need rest to heal it. More torn fibers result in a sprain, which limits use of the muscle for over a month.

A full rupture is the worst. Every fiber in the muscle is torn, and surgery is needed to repair it. Certain muscles are more at risk to injury than others. Muscles that cover two joints, like the hamstring, are top offenders.

Muscles also are more likely to be injured while contracting. Finally, muscles that make fast, twitchy motions are at risk.

Stay flexible to keep your body safe from pulled muscles.

So don't skip stretches before and after a workout.