External Rotation Sidelying
The External Rotation Sidelying primarily works the Infraspinatus, Teres Minor, with secondary activation of the Posterior Deltoid and stabilizer support from the Subscapularis. It is a dumbbell isolation exercise at beginner difficulty.
The External Rotation Sidelying is an beginner isolation exercise performed with dumbbell, following a rotation movement pattern. It primarily targets the Infraspinatus, Teres Minor, with secondary engagement of the Posterior Deltoid.
Lie on your side and externally rotate your shoulder with a dumbbell.
| Equipment | Dumbbell |
|---|---|
| Difficulty | Beginner |
| Type | Isolation |
| Movement | Rotation |
| Force | Static |
| Laterality | Unilateral |
| Primary | Infraspinatus, Teres Minor |
| Secondary | Posterior Deltoid |
Muscles Worked
The Infraspinatus, and Teres Minor are the primary movers, collectively driving the movement and absorbing the greatest share of the load. The Posterior Deltoid assists as a secondary mover, contributing to force production without bearing the primary load. The Subscapularis act as stabilizers, maintaining joint position and postural alignment throughout the movement.
Primary Muscles
- Primary Muscle Infraspinatus (back)
- Primary Muscle Teres Minor (back)
Secondary Muscles
- Secondary Muscle Posterior Deltoid (shoulders)
Stabilizer Muscles
- Stabilizer Muscle Subscapularis (back)
How to Perform
Preparation
- Grasp dumbbells with firm grip.
Execution
- Rotate torso against resistance through full range of motion.
- Return to starting position under control.
- Repeat on opposite side.
Comments
- Perform equal reps on each side.
- Maintain tension throughout the hold.
Tips & Common Mistakes
- Initiate rotation from your hips and torso, not just your arms.
- Control the return movement — resist letting momentum do the work.
- Keep your core engaged throughout to protect your spine during rotation.
Programming Suggestions
Adapt your sets and reps to your training goal. As a beginner-friendly exercise, start with lighter loads and focus on form before progressing weight.
| Strength | 3–4 sets × 6–8 reps at 75–85% 1RM with 90–120 seconds rest. |
|---|---|
| Hypertrophy | 3–4 sets × 10–15 reps at 60–75% 1RM with 60–90 seconds rest. |
| Endurance | 2–3 sets × 15–25 reps at 40–60% 1RM with 30–45 seconds rest. |
Alternative Exercises
These exercises target the same primary muscles (Infraspinatus, Teres Minor) and can be substituted based on your equipment or variation preferences.
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