Home Physiotherapy Exercise App with On-Device Rep Counting
A final year project that builds a mobile app for physiotherapy patients doing prescribed exercises at home: the phone camera counts reps and checks range of motion on the device, and the physiotherapist sees adherence and progress. Pose estimation, privacy by design and a clinic-facing view, sized for 2 to 4 students.
Advanced
Needs a team, real planning, and a supervisor who knows the area.2 semesters · 3 students
7 to ship
3 optional extrasSuggested stack
What you should ship
- Patient app that plays an exercise, watches through the front camera and counts repetitions for at least 5 common knee, hip and shoulder exercises
- Joint-angle based range-of-motion measurement per rep, with a simple spoken cue when a rep is too shallow
- All video processed on the device; only rep counts, angles and timestamps leave the phone
- Physiotherapist web view to assign a programme, set targets and see daily adherence and range-of-motion trends
- Labelled evaluation set of recorded sessions from at least 8 volunteers with manual rep counts and goniometer or video-measured angles
- Report of rep counting accuracy and angle error per exercise, including failure cases such as poor lighting and loose clothing
- Frame rate and battery measurements on a mid-range and a low-end Android phone
If you have time left
- Side-view calibration so knee angles are measured from the correct camera position
- Exercise recognition so the app knows which exercise is being done without a manual choice
- Urdu and English voice cues with adjustable speaking rate for older patients
The problem with home physiotherapy
After a knee replacement, a sports injury or a frozen shoulder, most recovery happens at home. The physiotherapist sees the patient once a week or less, hands over a sheet of exercises, and hopes they are done. Patients skip sessions, do fewer reps, or do them with too little range of motion, and the physiotherapist has no way to know until the next visit shows slow progress. Travel to a clinic is expensive and tiring for older patients, so visits get spaced further apart.
A phone propped on a chair can see the patient. If it can count reps and estimate joint angles reliably, the patient gets feedback and the clinician gets data between visits.
What already exists and the gap
- Kaia Health Motion Coach: on-device pose estimation that gives real-time feedback on exercise form; sold through insurers and employers in specific markets.
- Physitrack and PhysiApp: home exercise programmes with a large video library, and a webcam motion capture feature that counts reps and tracks joint angles.
- Generic fitness rep counters: count squats and push-ups but do not measure clinical range of motion or report to a clinician.
The gap is an affordable, clinic-facing tool that works on ordinary Android phones, reports measured angles rather than just counts, and can be adopted by a small private clinic without an insurer contract.
What you build
- Patient app: today's exercises, a short demo, camera session with counting and cues, a completion summary.
- Physiotherapist view: patients, assigned programmes, targets, adherence calendar and angle trend per exercise.
- Backend: programmes, sessions and numeric results only.
The technically interesting part
Pose estimation models give you 2D or 3D keypoints per frame. Turning those into clinical numbers is the project.
- Rep counting as a state machine over a smoothed joint angle, with hysteresis thresholds so jitter does not create extra reps.
- Angle measurement: a knee angle from a front camera view is distorted; you must guide the patient to a side view, check keypoint confidence and reject frames where the joint is hidden.
- Real-time on weak hardware: keep the pipeline above a usable frame rate by downscaling, skipping frames and running inference off the UI thread.
Show evaluators a plot of raw versus smoothed angle with detected reps marked, and a table of error against ground truth. This is the same privacy pattern Kaia and Physitrack describe: video stays on the device and only structured numbers are sent.
How to evaluate it
- Rep count accuracy per exercise against manual counts on at least 8 volunteers.
- Mean absolute angle error against a goniometer or a carefully annotated side-view video.
- Frames per second and battery drain per 15-minute session on two phone tiers.
- A short usability session with a practising physiotherapist reviewing the clinician view.
Suggested plan
- Weeks 1 to 3: meet a physiotherapist, pick 5 exercises and agree what "a good rep" means for each.
- Weeks 4 to 8: camera pipeline, pose model, angle calculation, first rep counter.
- Weeks 9 to 14: record the evaluation set, tune thresholds, measure accuracy.
- Semester 2, weeks 1 to 5: patient app flow, cues, backend and clinician view.
- Weeks 6 to 10: performance work on the low-end phone, pilot with volunteers.
- Weeks 11 to 14: final evaluation and report.
Path to a product
Sell to small physiotherapy clinics per active patient per month; the clinic gains adherence data and can offer remote follow-ups. A first customer is a clinic near your university that already sends exercises on WhatsApp. Any clinical use claims need proper validation and ethics review, so position the first version as an adherence tool, not a diagnostic device.
Scope warning
Do not train your own pose model. Do not diagnose or recommend treatment. Do not store or upload video. Keep to 5 exercises done well rather than 30 done badly.
Learn what you need on Sefism
- Mobile roadmap : camera, threading and performance on Android.
- Machine learning roadmap : evaluation and error analysis for the counting pipeline.
- Machine learning cheat sheet : metrics and validation quick reference.
- Android developers documentation : CameraX and background execution.
- OWASP mobile application security : protecting health data on the device and in transit.
Get help with this idea
Choosing exercises and building a trustworthy ground-truth set are the decisions that shape your grade. A mentor can help you cut the scope to what your team can finish, choose between the stack options above, and design an evaluation your examiners will respect. You still build it; the help is on decisions, not code.
New here? Create a free account first.
Ideas and guidance, not finished projects
These are project ideas and scoping guidance, published free for students to use as a starting point. I do not build, write, or sell final-year projects, and I do not complete coursework for anyone. Take an idea, make it yours, and build it.
Not sure this one fits you?
I help students pick an idea that matches their skills and their deadline, then scope it down until it is finishable. Guidance only, never done for you.
Stuck on something specific?
Writing only gets you so far. If you want an answer to your situation rather than the general case, book a session and we will work through it together. Sessions are free for approved Sefism members, and a few slots open each week.
Follow along
New writing, resources and project ideas land here first.