Your deltoid muscles make up a main muscle group in your upper body. They’re connected with many other muscles and bones in your upper back, neck, and shoulder region and are extremely mobile. They ...

The deltoid is a round muscle that goes around the top of your upper arm and shoulder. The main function of the deltoid is to help you lift and rotate your arm. There are three parts of the deltoid ...

For fitness-minded folks, muscle testing can sound pretty intriguing. But it turns out that it has little to do with fitness...or even muscles. On a basic level, muscle testing looks at a muscle and ...