Reverse Lunge Form Check
Wondering if your reverse lunge is solid? Prop up your phone — GOODREPS watches your knee angle (hip → knee → ankle) live and scores every rep while you train your quads and glutes, with hamstrings assisting. 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 REVERSE LUNGE
Setup Turn side-on to the camera, feet hip-width, hands at your sides.
- Step one foot straight back and lower until both knees are ~90°.
- Keep your torso upright and your front knee stable.
- Push through the front heel to return; alternate legs.
Same sheet as the ⓘ panel in the app — animated demo included.
THREE STEPS TO A SCORED REVERSE LUNGE
Prop your phone and get in frame
Phone at roughly torso height, set up side-on to 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 knee angle (hip → knee → ankle) on-device — no wearables. Bodyweight first; dumbbells when the pattern is clean.
Move — and watch the form bar
The bar fills from ~160° toward ~100° at the bottom. Cut range short and it tells you; full ROM is what counts.
WHAT THE CAMERA WATCHES
- Your front knee angle through the drop toward 100° and back up to 160°.
- A soft back knee kissing toward the floor without collapsing.
- Upright torso — the camera notices a forward tip.
COMMON REVERSE LUNGE MISTAKES
Front knee blasting past the toes
Step back far enough that the front shin stays close to vertical.
Slamming the back knee
Control the descent. Tap the floor; do not pound it.
Leaning onto the front toe
Keep front heel planted and drive up through it.
Tiny steps
A short reverse step turns the lunge into a messy squat. Give yourself room.
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 reverse lunge 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.