Standing 90/90 Dumbbell External Rotation — how to, muscles worked, alternatives

How to do the Standing 90/90 Dumbbell External Rotation

Raise one upper arm to shoulder height, elbow bent 90 degrees.
Start with the forearm pointing down, free hand on your hip.
Rotate the forearm up until it points to the ceiling.
Slowly rotate back down, keeping the elbow at shoulder height.
Finish reps, then switch sides.

Full technique — 7 steps

Stand tall with feet about hip width apart, holding a dumbbell in one hand.
Raise that upper arm out to the side to shoulder height and bend the elbow to 90 degrees.
Start with the forearm pointing down and place your free hand on your hip.
Set your shoulders down and keep your elbow at shoulder height throughout.
Rotate your forearm upward until it points straight up, keeping the elbow angle fixed.
Lower the dumbbell back to the forearm-down position along the same arc.
Complete all reps on one side, then switch arms and repeat.

Common mistakes

Elbow dropping below shoulder height
Opening or closing the elbow angle
Shrugging shoulders toward ears
Swinging the torso for momentum

Form cues

Elbow stays at shoulder height
Elbow angle stays fixed
Keep shoulders down
Keep torso quiet

Where to start and where to go next

Same muscles, same movement. Too hard for now — step down; once it gets easy — step up.

Easier Standing Mini Band External Rotation Beginner
This exercise Standing 90/90 Dumbbell External Rotation Beginner

Too hard for now? Start with the Standing Mini Band External Rotation.

Quick answers

What muscles does the Standing 90/90 Dumbbell External Rotation work?

Primary: Infraspinatus 9/10, Teres minor 8/10. Also works: Rear delts 5/10, Side delts 4/10, Supraspinatus 4/10, Traps 3/10.

When should I do the Standing 90/90 Dumbbell External Rotation in a workout?

Warm-up. Done at the start to get the body ready. ≈ 7 min with rest.

How many sets and reps of the Standing 90/90 Dumbbell External Rotation?

Strength: 2–3 sets of 8–10 reps, rest 1 min, 3 reps in reserve. Muscle growth: 2–3 sets of 12–15 reps, rest 1 min, 3 reps in reserve. Endurance: 2–3 sets of 15–20 reps, rest 45 s, 4 reps in reserve.