Hammer Curl Form Check
Wondering if your hammer curl is solid? Prop up your phone — GOODREPS watches your elbow angle (shoulder → elbow → wrist) live and scores every rep while you train your biceps and forearms. Free in your browser today; coming to Google Play and the App Store.
Coming to Google Play & the App Store▶ Try The Form Check
LIVEHOW TO DO A PROPER HAMMER CURL
Setup Stand facing the camera, weights at your sides, palms facing in (thumbs forward).
- Curl up keeping your palms facing each other the whole way.
- Squeeze at the top, then lower slowly to a full stretch.
- Keep your elbows tight to your ribs.
Same sheet as the ⓘ panel in the app — animated demo included.
THREE STEPS TO A SCORED HAMMER CURL
Prop your phone and get in frame
Phone at roughly torso height, stand facing the camera. A quick camera test checks lighting, distance, and angle before you start.
The camera locks a 17-point skeleton on you
GOODREPS measures your elbow angle (shoulder → elbow → wrist) on-device — no wearables. A pair of dumbbells — palms face each other the whole way.
Move — and watch the form bar
The bar fills from ~155° toward ~50° at the bottom. Cut range short and it tells you; full ROM is what counts.
WHAT THE CAMERA WATCHES
- Your elbow angle, live — from roughly 155° hanging long up toward 50° at the top of the curl.
- Your personal range of motion — after 3 clean reps the counter calibrates to your arms.
- That neutral grip — thumbs stay up; rotate and it stops being a hammer curl.
COMMON HAMMER CURL MISTAKES
Swinging the hips
Momentum from the torso steals the work from your brachialis. Brace, then curl — no cheat reps.
Elbows drifting forward
Keep elbows pinned at your sides. If they creep forward you are turning it into a front raise.
Twisting into a regular curl
Palms stay facing each other. Supinating mid-rep changes the exercise.
Cutting the bottom short
Fully straighten at the bottom so every rep starts from a real stretch.
PRIVATE BY DESIGN
Pose detection runs in your browser via TensorFlow.js. Camera frames are analyzed in real time and immediately discarded — nothing is recorded, nothing leaves your phone, and we never see them. Sign-in is optional; skip it and everything stays local.
QUESTIONS, ANSWERED
Do I need any equipment to check my hammer curl form?
Just your phone for most variations. Add free weights when the pattern is clean — the app still scores the movement either way.
Does it work in a home gym or low light?
Run the built-in camera test first — it checks your lighting, distance, and angle with live green checks before you start. If a rep still slips through, manual counting is always one tap away.
Is my camera feed uploaded anywhere?
No. Pose detection runs entirely on your phone, in your browser. Frames are analyzed in real time and immediately discarded — nothing is recorded, nothing is uploaded.
RELATED GUIDES
Free forever — camera counting for all 60 exercises, no account needed. Pro (voice coaching, programs, depth-camera form checks) is $7/mo, $49/yr, or $99 once. No ads, ever.