Side Lunge Form Check
Wondering if your side 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 and calves 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 SIDE LUNGE
Setup Face the camera, feet wide, toes pointing forward.
- Shift your weight to one side, bending that knee and pushing your hips back.
- Keep the other leg straight and both feet flat.
- Push back to center and switch sides.
Same sheet as the ⓘ panel in the app — animated demo included.
THREE STEPS TO A SCORED SIDE LUNGE
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 knee angle (hip → knee → ankle) on-device — no wearables. Bodyweight or a single kettlebell/dumbbell held at the chest.
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
- The working knee bending while the other leg stays long.
- Hips sitting back — this is a lateral squat pattern, not a curtsy.
- Chest up through the push back to stand.
COMMON SIDE LUNGE MISTAKES
Letting the knee cave inward
Track the working knee over the middle toes as you sit into the hip.
Trailing foot peeling and twisting
Keep the long-leg foot flat and pointed forward unless the app cues otherwise.
Cutting depth
Sit until the working thigh gets near parallel if your hips allow — shallow reps hide.
Rounding forward
Hinge the hips back with a proud chest. The camera sees a collapsed torso.
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 side 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.