External Rotation

Which muscles does it train?

Equipment needed

How to perform it

Isolation work is usually trained in a higher rep range: 2 to 4 sets of 10 to 15 reps with 45 to 90 seconds of rest, performed under control.

Execution and technique cues

• Sit upright or stand tall, hold the dumbbell in one hand, and pin the elbow firmly against your side with the forearm bent to 90 degrees.
• Rotate the forearm outward slowly until it is parallel to the floor or just above, keeping the elbow in contact with the body throughout.
• Keep the shoulder blade still and the shoulder depressed. The movement comes solely from the glenohumeral joint, not from trunk rotation.
• Return the forearm under control back to the starting position, resisting the weight on the way in to train the eccentric as well.

Common mistakes

• Allowing the elbow to drift away from the body, which alters the mechanics and reduces the isolated load on the rotator cuff.
• Using too much weight, causing the trunk to rotate or the shoulder to hike in order to complete the rep.
• Dropping the forearm back without control, skipping the eccentric phase that is critical for rotator cuff strength and tendon health.

Frequently asked questions

Which muscles does the dumbbell external rotation target?

It primarily trains the infraspinatus and teres minor, two of the four rotator cuff muscles responsible for externally rotating the humerus and stabilizing the shoulder joint.

How heavy should the dumbbell be?

The rotator cuff muscles are small and not designed for heavy loads. For most people 1 to 5 kg is appropriate for prehab or accessory work. Choose a weight that allows a slow, controlled rotation through the full range without any compensatory movement.

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