A muscle doesn't rotate the shoulder. The ligaments that connect your shoulder blade to your arm, to your rib cage all work in a ball and socket type of way allowing you to rotate your arm 360o.
The deltoid muscle is one muscle with three sections. Each one is located in your left and right shoulder. All three of them together perform an action called abduction to the shoulder (glenohumeral joint.)in the upper armIt is located at the shoulder.
Deltoid
hamstringsHamstring
shoulder flexion shoulder adduction shoulder horizontal extension
it works your abs
serratus anterior
supraspinatus
it works your abs
one often used for strengthening all the upper arm and shoulder muscles is?
Deltoid (delta = triangle + -oid = looks like/resembles) The deltoid muscle is a triangular shaped muscle of the upper arm. It is also known as the common shoulder muscle.
Any dam will raise the water level behind it.
The agonist muscle used in a side leg raise is the adductor.