A mini squat is a squat that stops early: you bend your knees a third to half of the way to a chair seat, then stand back up. It looks too easy to count as exercise, but it works the quadriceps through the range where the kneecap is least loaded, so you can build strength without provoking a flare.
Why therapists start shallow
A 2014 study in the Journal of Orthopaedic and Sports Physical Therapy estimated patellofemoral joint stress, the pressure between kneecap and thigh bone, at knee angles from 0 to 90 degrees during squats. Stress was highest at 60, 75 and 90 degrees of bend, and the authors suggested keeping squats between 0 and 45 degrees. It was a small study of ten healthy adults, so treat it as a guide, but clinics follow it: an NHS Royal Orthopaedic Hospital leaflet for knee osteoarthritis caps the mini squat at 45 degrees, and Cleveland Clinic lists deep squats among the movements people with knee arthritis should avoid.
What the evidence says about strengthening for knee OA
Exercise is a core treatment in every current knee osteoarthritis guideline, and the 2024 Cochrane review supports that. It pooled 139 randomised trials with 12,468 participants and found low to moderate certainty evidence that exercise probably improves pain, function and quality of life. The gains were modest: compared with usual care, pain improved by about 13 points on a 100-point scale and function by about 12. No type of exercise came out ahead, so a shallow squat you do most days beats a perfect program you skip.
Muscles worked
- Quadriceps: the main target. They control the lowering, drive you back up, and are the muscles that most often weaken around a painful knee.
- Gluteus maximus and medius: the hips share the load and stop the knees drifting inward.
How to do it
- Feet hip-width apart, fingertips on a counter or chair back.
- Push your hips back a little and bend your knees to about 30 degrees, where you can still see your shoelaces.
- Heels down, each knee tracking over the second toe, not collapsing inward.
- Pause, then press through the whole foot to stand tall.
- Start with three sets of five (Cleveland Clinic) or ten reps (NHS); your therapist sets the number.
Counter-balance and chair-supported versions
If balance is the limit, hold a counter with both hands. If the knee is the limit, a chair behind you works as a depth stop: sink until your bottom brushes the seat, then stand. The counter-balance version holds a light weight at your chest; it lets you sit back into the hips and keep the shins more upright, which is kinder on the kneecap.
Progressing depth and reps
Change one thing at a time. First add reps, from 5 up to 10 or 12 per set. Then add a set. Then slow the lowering phase. Only then deepen the squat, in small steps toward 60 degrees, and only if the knee is settled the next morning. NHS leaflets use a simple test: any ache should ease within a couple of hours. If it lingers, drop back a step. Single-leg mini squats come last.
If getting out of a chair is also part of your plan, see our sit-to-stand guide
Doing this exercise in a guided session
Depth is hard to judge alone; most people go deeper than they think. In a KineTrue camera-guided session the app measures your knee angle on each rep and shows whether you stayed inside the range your therapist set, and the recorded reps give them something concrete to review before letting you go deeper. The decision stays with them.
Stop and check with your therapist or doctor if the knee swells, locks, gives way, or if pain during the squat is sharp rather than a dull working ache. A knee that is clearly worse the next day is a signal to reduce depth or reps before the next session.