Tight hip flexors, especially a deep muscle called the psoas, can silently stress your spine. Here's why this muscle deserves ...

controlled rep are the back and shoulders. In fact, if you’ve ever tried (and struggled) to get your chin over the bar, there's a good chance your pulling muscles weren’t fully prepped yet.

Medically reviewed by Jennifer Steinhoff, MD The humerus is your upper arm bone. It is the longest bone in the upper part of ...

(CNN) — When your shoulders feel stiff ... aren’t firing properly, larger muscles such as the upper trapezius (located at the side of the neck and top of the back) and pectoralis major ...