💪 Hammer Curl Form Guide
Build powerful forearms and biceps.
SportsReflector AI analyzes your hammer curl form by tracking key landmarks like the shoulder, elbow, and wrist joints. We monitor elbow flexion and extension angles, ensuring a full range of motion, and detect torso stability to prevent compensatory movements. Metrics tracked include concentric and eccentric phase duration, joint angle consistency, and overall movement efficiency.
Primary Muscles
Brachialis, Brachioradialis
Equipment
Dumbbells
AI Score Categories
6 metrics tracked
What AI Analyzes in Your Hammer Curl
SportsReflector tracks 6 key metrics to generate your 0–100 form score.
AI Form Score
Every Hammer Curl session gets an overall form score plus category-level scoring for each metric above.
4 Hammer Curl Mistakes AI Catches
These are the most common Hammer Curl form errors — and the ones most likely to cause injury or limit your progress.
Swinging the dumbbells by leaning back or using hip drive reduces the tension on the target muscles (brachialis, brachioradialis, biceps) and shifts the load to the lower back and shoulders. This decreases exercise effectiveness and increases the risk of lower back strain.
Fix: Keep your torso rigid and stable throughout the movement. Initiate the curl solely with your arm muscles. Imagine your elbows are pinned to your sides. Reduce the weight if you cannot maintain strict form.
Not fully extending the arms at the bottom or not fully flexing the elbows at the top limits muscle activation and growth potential. Partial reps do not provide the full stretch and contraction necessary for optimal development of the brachialis and brachioradialis.
Fix: Ensure your arms are fully extended at the bottom, feeling a stretch in the biceps. At the top, curl until your forearms are perpendicular to the floor or slightly higher, achieving a strong peak contraction. Aim for an elbow flexion of 140-160 degrees at the top and full extension (170-180 degrees) at the bottom.
Allowing the elbows to move away from the body, especially during the concentric phase, shifts emphasis away from the brachialis and brachioradialis and can place undue stress on the shoulder joint. It also reduces the isolation of the target muscles.
Fix: Keep your elbows tucked close to your sides throughout the entire movement. Imagine a string connecting your elbows to your torso, preventing them from drifting. Focus on moving only your forearms.
Bending the wrists significantly (either flexing or extending) during the curl can lead to wrist discomfort or injury, and it reduces the direct tension on the brachialis and brachioradialis by involving the forearm flexors/extensors more than necessary. The hammer curl grip is specifically designed to keep wrists neutral.
Fix: Maintain a neutral wrist position throughout the entire exercise. Your wrists should be straight, in line with your forearms, as if you're holding a hammer. Avoid any bending or breaking at the wrist joint.
Muscles Worked
Get Your Hammer Curl Form Score
Record your Hammer Curl on your iPhone and get an instant 0–100 AI form score with specific corrections for every mistake above.
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