Exercise guide
Seated External Rotation On A Chair
- Beginner
- Isolation
- Rep-based
- Shoulders
- Upper arms
This isolation exercise targets the rotator cuff and posterior deltoids to improve shoulder stability and posture. It is an effective way to strengthen the external rotators using only the weight of the arm and controlled tension.
Reviewed by the Crucible team · Updated June 2026
Muscles worked
Setup
- Sit sideways on a chair or bench with your feet flat on the floor for stability.
- Rest the elbow of your working arm on your knee or the top of the chair's backrest.
- Bend your elbow to a 90-degree angle with your forearm pointing forward, parallel to the floor.
- Sit tall with your chest up and your shoulder blades retracted and depressed.
How to do it
- Exhale as you rotate your forearm upward and backward in a semi-circular motion as far as your range of motion allows.
- Keep your elbow pinned to your knee or the chair backrest throughout the entire movement.
- Inhale as you slowly lower your forearm back to the starting position under control.
- Perform the movement with a controlled 2-1-2-0 tempo (2 seconds up, 1-second pause, 2 seconds down).
Form checklist
- Maintain a strict 90-degree bend in the elbow at all times.
- Keep your shoulder down and away from your ear to avoid trap compensation.
- Ensure the rotation occurs only at the shoulder joint without leaning your torso.
- Keep your wrist straight and neutral throughout the set.
Pro tips
- Imagine there is a rod running through your upper arm; rotate around that axis without letting the elbow slide.
- Focus on the 'mind-muscle connection' by visualizing the small muscles on the back of your shoulder blade doing the work.
Make it harder
- Slow down the eccentric (lowering) phase to 4 seconds to increase time under tension.
- Hold a light household object, like a full water bottle, to provide incremental resistance.
Frequently asked
- What muscles does the seated external rotation on a chair work?
- The seated external rotation on a chair primarily targets the deltoids, and also works the biceps and rotator cuff as secondary muscles.
- What equipment do you need for the seated external rotation on a chair?
- The seated external rotation on a chair requires no equipment — just your body weight.
- Is the seated external rotation on a chair good for beginners?
- Yes. The seated external rotation on a chair is a beginner-friendly movement and a strong foundation to build on.