Is squatting bad for knee arthritis? How to squat safely with arthritic knees
No: for most people with knee osteoarthritis, a few sets of controlled squats to a comfortable depth are not bad for the knee and are one of the best ways to strengthen the muscles that protect it. What is linked to more knee arthritis is squatting or kneeling for hours a day, as in some jobs, and long static deep holds. Exercise is a different dose.
Below: what the research actually links to arthritis, what the treatment guidelines say about strengthening, how deep to go, a simple pain rule, seven squat versions from easiest to hardest with sets and reps, a 6-week plan, the mistakes that flare knees and when to get checked first.
Where the "squats ruin your knees" idea comes from
It comes from real research, but about a different thing. Studies of workers found that people whose jobs involved squatting or kneeling for long periods had more knee osteoarthritis. A UK study of people on a waiting list for knee replacement (Coggon and others, 2000) found more kneeling and squatting in their working lives than in matched controls, especially in people who were also heavy. The Beijing Osteoarthritis Study (Zhang and others, 2004) asked adults over 60 how long they had spent squatting each day at age 25: the more hours of daily squatting, the more knee arthritis they had decades later, and the link was clearest at two or more hours a day.
That is hours of deep squatting, every day, for years, often while carrying loads. A home strength session has perhaps 30 to 60 squats, each lasting a few seconds, two or three times a week. A 2019 review of deep squatting (Agarwal and others, Cardiff University) concluded that squatting done in moderation is likely helpful for keeping knee movement, strength and balance, while long sustained deep squatting is the part to avoid.
What the arthritis guidelines say about strengthening
Every major guideline puts exercise at the centre of knee osteoarthritis care, before injections or surgery:
- The American College of Rheumatology and Arthritis Foundation guideline (2019) strongly recommends exercise for knee osteoarthritis.
- The Osteoarthritis Research Society International guideline (OARSI, 2019) lists strengthening exercise as a core treatment for everyone with knee arthritis.
- NICE in the UK (NG226, 2022) recommends a tailored exercise program, including strengthening, for everyone with osteoarthritis.
Squat patterns are part of many of these programs. The Danish GLA:D program, used in clinics in many countries, teaches people with knee and hip arthritis to squat, lunge and step with good knee control in 12 supervised sessions over six weeks.
Why it helps: your thigh muscles, especially the quadriceps at the front, act as shock absorbers for the knee. Weak thighs are common in knee arthritis and linked to more pain and harder daily tasks like stairs and getting out of a chair. Cartilage also has no blood supply of its own; it is fed by joint fluid as the joint moves and is loaded. Moderate loading helps it; complete rest does not.
How deep should you squat with knee arthritis?
As deep as you can go with little or no pain and good control, and no deeper for now. For many people with arthritic knees that starts as a quarter or half squat, often to a chair or a high box, and gets deeper as the legs get stronger. There's no rule that you must reach thighs parallel to the floor.
- A higher seat means less bend and less load on the kneecap. Start at a height you can rise from without your hands.
- Sitting back, as if onto a chair, keeps more of the load on your hips and less on the front of the knee.
- Pain that only appears past a certain depth tells you where your range ends today.
A pain rule you can use while you train
Some discomfort is normal and safe with arthritis. Physical therapists often use a simple pain-monitoring rule, adapted from Thomeé's model:
| Pain (0 = none, 10 = worst) | What it means | What to do |
|---|---|---|
| 0–2 | Safe zone | Carry on; you can progress next session |
| 3–5 | Acceptable | Carry on, as long as it settles by the next morning and doesn't build each week |
| Over 5, or worse the next morning | Too much for now | Next time, use a higher seat, less weight, fewer reps or an easier version |
Sharp, catching pain, a knee that gives way, or swelling that appears after training are signs to ease right back and get the knee looked at.
Seven squat versions for arthritic knees, easiest first
Start with the first one that feels easy-to-moderate, and move to the next when you can do 3 sets of 12 with pain at 2 or less.
| # | Move | How | Sets and reps |
|---|---|---|---|
| 1 | Seated quad squeeze | Sit, straighten one knee, squeeze the front of the thigh 5 seconds, lower | 2 × 10 each leg |
| 2 | Sit-to-stand from a high seat | A chair plus a cushion. Feet hip-width, lean forward, stand, sit back slowly | 2–3 × 8–10 |
| 3 | Counter-supported squat | Hold the kitchen counter, sit back a short way, stand | 2–3 × 10–12 |
| 4 | Wall slide (short range) | Back on a wall, feet a stride forward, slide down a few inches, hold 5 seconds, up | 2–3 × 8 |
| 5 | Box squat to a normal chair | Sit back to touch the chair lightly, stand without rocking | 3 × 10–12 |
| 6 | Goblet box squat | As above, holding a dumbbell at your chest | 3 × 8–12 |
| 7 | Goblet squat, freestanding | To your pain-free depth, 3 seconds down | 3 × 8–12 |
A note on the wall slide: it is a short hold, not the long static deep squat studies warn about. Keep the hold to 5–10 seconds and the depth shallow.
If squats hurt even at the easy end, there are other ways to build the same muscles. Our guide to squat alternatives for bad knees has nine moves easiest to hardest, and knee friendly exercises for legs has a full leg workout.
How to squat with good form on sore knees
- Feet: hip-width or a little wider, toes turned out slightly, weight spread over the whole foot.
- Knees: let them follow the line of your second toe. Caving inward loads the knee unevenly.
- Hips: start by pushing your hips back, then bend the knees.
- Speed: 3 seconds down, a short pause, up at a steady pace. No bouncing at the bottom.
- Breath: breathe out as you stand.
- Range: stop just above where pain starts.
Knees passing your toes is fine for most people and often needed to stay balanced; the old rule against it isn't backed by research. If it bothers your knee, sit back more to a chair.
A 6-week squat plan for knee arthritis
Two or three days a week, on days that aren't back to back. Add the rest of a full-body session (rows, presses, bridges) if you like.
| Weeks | Squat work | Other leg work |
|---|---|---|
| 1–2 | Sit-to-stand from a high seat, 2 × 8 | Seated quad squeeze 2 × 10; glute bridge 2 × 10 |
| 3–4 | Counter squat or box squat to a normal chair, 3 × 10 | Step-up on a low step 2 × 8 each leg; bridge 2 × 12 |
| 5–6 | Box squat 3 × 12, or goblet box squat 3 × 8 with a light dumbbell | Step-up 3 × 8 each leg; side-lying leg raise 2 × 12 |
Only move on when this week's work stayed inside the pain rule. A flare-up week is fine: go back a step for a week, then try again. If you want this built into a full program around your knees, back and time, the free home strength quiz does that in 2 minutes.
Mistakes that flare arthritic knees
- Doing too much too soon, especially after a break. Add one thing at a time: reps, then depth, then weight.
- Long deep holds at the bottom of a squat, or gardening and cleaning floors squatting for long stretches. Kneel on a pad or sit on a low stool instead.
- Bouncing out of the bottom.
- Squatting on a flare day. Use seated quad squeezes and bridges instead, and walk gently.
- Stopping all leg work because it ached once. Weak thighs make arthritis feel worse over time.
When to see a doctor or physical therapist first
See a doctor before training if your knee is hot, red and swollen, you can't put weight on it, it locks or gives way, you have a fever with joint pain, or pain followed a fall or twist. A physical therapist is worth it if pain stays above 5 out of 10 even on the easiest versions, or if you've had a knee replacement recently: follow your surgeon's plan first.
Weight matters too: the work studies found the strongest link between squatting jobs and arthritis in people carrying extra weight, and losing a modest amount of weight is recommended for people with knee osteoarthritis and overweight in the guidelines above.
Questions people ask
Should I avoid squats if I have arthritis in my knees?
Usually not. Use a version and depth that stays inside the pain rule. Most people can squat to a chair, and many get deeper over weeks.
Are deep squats bad for arthritic knees?
Deep squats load the knee more, and long deep holds have been linked to arthritis. Work in a shallower range first and go deeper only if it stays comfortable.
Can squats make knee arthritis worse?
Too much, too soon can flare pain for a day or two. Controlled squatting in a program has not been shown to speed up arthritis, and strengthening is a recommended treatment.
Are wall sits good for knee arthritis?
Short, shallow wall holds of 5–30 seconds are a common way to build the thighs when moving squats hurt. Keep the angle shallow.
How many squats a day for knee arthritis?
Two or three sets of 8–12, two or three days a week, is a typical starting dose. More isn't better if it breaks the pain rule.
Is squatting or lunging better for bad knees?
Squats to a chair are usually easier to control. Lunges load one knee at a time and are harder; step-ups onto a low step are a good middle ground.
A strength plan that starts where your knees are
The 2-minute home strength quiz asks about your knees, back, goal and time, then shows the 12-week plan it builds, with knee friendly versions of every leg move.
Take the quizMore plain guides on getting stronger at home: all our home strength guides.
Sources: Coggon D. et al., "Occupational physical activities and osteoarthritis of the knee", Arthritis & Rheumatism, 2000. Zhang Y. et al., "Association of squatting with increased prevalence of radiographic tibiofemoral knee osteoarthritis: the Beijing Osteoarthritis Study", Arthritis & Rheumatism, 2004. Agarwal B., Advani M., van Deursen R., Mullerpatan R., review of deep squatting and the knee, 2019 (Cardiff University ORCA record 122152). Kolasinski S.L. et al., 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee, Arthritis Care & Research, 2020. Bannuru R.R. et al., OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis, Osteoarthritis and Cartilage, 2019. NICE, Osteoarthritis in over 16s: diagnosis and management (NG226), 2022. Skou S.T. and Roos E.M., "Good Life with osteoArthritis in Denmark (GLA:D)", BMC Musculoskeletal Disorders, 2017. Thomeé R., "A comprehensive treatment approach for patellofemoral pain syndrome in young women", Physical Therapy, 1997. This guide is about exercise habits and is not medical advice; follow your doctor's or physical therapist's advice where it differs.