What Is the Psoas Muscle? The psoas (pronounced so-ezz) muscles are two large muscles in your lower back. You have one on either side of your spine. They're the main muscular connection between your ...

You have 20 muscles in your forearm, the part of your arm between your elbow and your hand. They help you move your arms, hands, and fingers and perform many of the tasks of daily life. You can strain ...