Hammer curl
Dumbbells
Primary muscles
Secondary muscles
A neutral, thumbs-up grip shifts work to the brachioradialis and brachialis.
Form cues
- Thumbs up the whole rep
- No swinging
- Squeeze at the top
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Primary SecondaryDrag · Pinch · Tap a muscle
What each muscle does in the hammer curl
| Muscle | Role | Action |
|---|---|---|
| Brachioradialis | Primary | Flexes the elbow, especially with a neutral grip |
| Brachialis | Primary | Flexes the elbow in any forearm position |
| Biceps brachii | Secondary | Flexes the elbow and supinates the forearm |
Primary muscles are the prime movers; secondary muscles assist or stabilise. The balance shifts with grip, stance, range of motion and technique.