The subscapularis muscle is very important for the Internal rotation of the humerus. The internal rotation supports the upper arm during abduction and adduction.
There are some band exercises that can help you strength the Subscapularis muscle... 1. Internal Rotation - uses medial internal rotation 2. External Rotation - uses lateral external rotation 3. Front Row - You have you hand up in front of you and with your arm extended pull back the band. 4. Side Row - You're side to the band with your hand facing the hip, pull down toward your body. (ADDUCTION)
THIS IS NOT A FAIR QUESTION NBME!!!
a)abduction: supraspinatus-deltoid-triceps-serratus anterior
b)adduction: subscapularis-pectoralis major-lattisimus dorsi- teres major
c)extension=horizontal abduction; post. deltoid, infraspinatus, teres minor
d)internal rotation: subscapularis
for isolated work out, d is better.
What puts internal rotation over adduction? Subscapularis muscle does both
Shoulder muscles that form the rotator cuff: Supraspinatus (suprascapular nerve)— abducts arm initially (before the action of the deltoid); most common rotator cuff injury (trauma or degeneration and impingement; tendinopathy or tear [arrow in A ]), assessed by “empty/full can” test
Infraspinatus (suprascapular nerve)—externally rotates arm; pitching injury
teres minor (axillary nerve)—adducts and externally rotates arm
Subscapularis (upper and lower subscapular nerves)—internally rotates and adducts arm