Dumbbell External Rotation
You cannot perform external rotation with a dumbbell while standing upright, because gravity does not provide resistance for the rotator cuff. You have to lie across a flat exercise bench. While standing upright you can perform cable external rotation.
Exercises that isolate the rotator cuff muscles are subtle movement that you should perform with very light weights because overloading these muscles with heavy resistance while isolating them can lead to injury.
The rotator cuff is a group of four muscles that helps to lift your shoulder up over your head and also rotate it toward and away from your body. The muscles of the rotator cuff are the supraspinatus, teres minor, infraspinatus, and subscapularis. The muscle group is often injured in activities that require the arm to go above the shoulder level, such as swimming, tennis, and throwing. The best way to prevent injuries is to make the muscles strong and flexible.
Lying Dumbbell External Rotation Exercise Guide
STARTING POSITION (SETUP): Lie across a flat exercise bench resting on your upper back, keeping your elbow in contact with the bench. Holding a dumbbell, lay your forearm across your waist so it is parallel to the floor.
EXECUTION (MOVEMENT): Keeping your upper arm in tight to your body, rotate your shoulder so that your forearm moves in an arching motion from your waist to a vertical position (until your forearm is vertically upright – perpendicular to your abdomen). Hold for a one-count at the top and then return to the start position and repeat for the desired amount of repetitions. Then switch to the other arm.
- You may place a rolled up towel under the elbow for better isolation of the infraspinatus and teres minor.
- Your arm should be bent 90 degrees. Keep your elbow fixed as you rotate your arm.
- Side Lying Dumbbell External Rotation. Lie on your side on the floor or a flat bench.
- Dumbbell Incline Shoulder External Rotation. Lie on your left/right side on an incline bench.
- Cable External Rotation. You can perform this exercise standing and with cables.
Muscles Engaged in Dumbbell External Rotation
Main muscles: infraspinatus, teres minor
Secondary muscles: deltoid (rear)
Antagonists: subscapularis, latissimus dorsi, pectoralis major