Sidelying External Rotation with DB

Setup

Lie on your side, bottom arm supporting your head or extended for balance. Top arm's elbow bent 90 degrees and pinned to your ribcage, forearm resting across your stomach, holding a light dumbbell.

Execution

1. 1Keep the elbow glued to the ribs throughout the entire movement
2. 2Rotate the forearm upward like a door swinging on a hinge until it points at the ceiling
3. 3Pause briefly at the top, resisting the urge to let the shoulder roll back
4. 4Lower with control back to the starting position

Key cues

• Elbow stays pinned to your side the whole rep
• Rotate from the shoulder, not by leaning your torso back
• Use a light weight — this is a cuff isolation drill, not a strength lift
• Keep the wrist neutral, don't let it cock back

Common faults

• Elbow drifting away from the ribs, turning it into a lateral raise
• Using too heavy a dumbbell and swinging the torso to compensate
• Rushing the tempo instead of controlling both directions
• Rolling the shoulder blade forward at the top of the rotation

Tweaks

• Perform with a light resistance band instead of a DB
• Add a 1-2 second pause at end range for extra cuff endurance
• Progress to standing cable/band external rotation once strong

Muscles

Notes

One of the most-prescribed shoulder prehab exercises in sports medicine. Very light loads (2-8 lb) are standard — this is not a mass-building movement.

Sources

• E3 Rehab - Rotator Cuff Exercises
• Prone Y-T-W for Shoulder & Scapular Strength - SLAP Rehab

Attribution: Physical therapy / rotator cuff rehab canon