Published October 31, 2026 · Updated November 1, 2026 · Protocol Archive Editorial
Exercises after ACL reconstruction: early and mid-stage rehab
Talk to your doctor first. General education, not medical advice.This content is general education, not medical advice, diagnosis or treatment. Get approval from your physician or another qualified healthcare provider before starting any exercise program, especially if you have a medical condition, a recent injury or surgery, are pregnant, or take medication. Stop and seek medical advice if an exercise causes pain, dizziness, chest discomfort or shortness of breath. You choose to exercise at your own risk. Read the full medical disclaimer.
ACL reconstruction replaces a torn anterior cruciate ligament with a graft, often taken from your own hamstring or kneecap tendon. The graft needs time to heal and strengthen, and NHS leaflets note that it is at its weakest around 6–12 weeks after surgery.
Rehab usually follows a clear order: first restore full knee movement, especially full straightening, then rebuild leg strength, then work toward everyday tasks, and finally sport. Progression is meant to be guided by how your knee is doing, not by the calendar alone.
This page covers the early and middle stages that you can do at home alongside supervised physical therapy. It is not a full return-to-sport program. If you have not had surgery, see our separate guide to exercises for an ACL injury.
Stage 1: Full straightening and quad activation
Get the knee fully straight, switch the thigh muscle back on, control swelling and start regaining bend.
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Ankle Pumps
Helps circulation in the leg while you are less active after surgery.
Typical dose: 10 reps, several times an hour while resting, for the first few days1
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Heel Prop for Knee Straightening
Getting the knee fully straight as soon as possible is a priority. One NHS program allows up to 15 minutes every few hours.
Typical dose: Rest the ankle on a rolled towel with the knee unsupported and let it straighten; build up to as long as your team advises, several times a day2,3
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Quad Sets (Quadriceps Setting)
If you cannot get the knee fully straight, do this exercise first.
Typical dose: Tighten the thigh to press the knee down, hold 5 seconds, 10 reps, 3–5 times a day1,2
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Heel Slides
One NHS program aims for about 90 degrees of bend early on and 0–100 degrees by 2 weeks, as a guide only.
Typical dose: Slide the heel toward you, 10 reps, 3–5 times a day, within comfort and any brace limit1,2
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Patellar (Kneecap) Mobilization
Keeps the kneecap moving freely. Avoid pressing on wounds or dressings.
Typical dose: Gently glide the kneecap up, down and side to side, holding each position about 5 seconds, 10 reps1,2
- Do not rest with a pillow under the knee, as this can make it hard to regain full straightening. Rest the lower leg, not the knee, on a pillow when elevating.2
- Raise the leg regularly, especially in the first 72 hours, and use ice wrapped in a towel for up to 15–20 minutes every few hours, never directly on the skin.1,2,3
- Avoid standing or walking for more than 20–30 minutes at a time early on. Increased pain and swelling at the end of the day means you have done too much.1,3
- If you have a brace, wear it as instructed and do not change its range settings unless your team tells you to.1
Stage 2: Regain bend and build basic strength
Reach near-full bend, walk without crutches or a limp, and start rebuilding thigh and calf strength.
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Supported Leg Raise
Only once your team clears it. Some programs avoid lifting the leg against gravity for about 2 weeks. If the knee bends as you lift, go back to quad sets.
Typical dose: Lock the knee straight, then lift the leg; 10 reps, a few times a day1,2
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Mini Squat
Keep weight even on both legs and the knees in line with your toes.
Typical dose: Holding a support, quarter squats, 2–3 sets of 10; deepen gradually toward a half squat as your therapist advises1,3
-
Toe Stand Strength Exercise
Calf strength helps restore a normal walking pattern.
Typical dose: Hold 5–10 seconds at the top, 10–20 reps; progress to the operated leg only3
- Most people can put full weight on the leg straight after surgery, but your surgeon may ask for partial weight bearing for a short time.1,2,3
- Stop using crutches when you walk without a limp and can take weight with the knee locked straight, with your therapist’s agreement.2,3
- A static bike with low resistance is often added once you have about 100 degrees of bend, starting with under 10 minutes.1,2
Stage 3: Single-leg strength and balance
Build strength and control on the operated leg and improve balance until it matches the other side.
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Step-Ups
Move slowly and keep the knee from drifting inward.
Typical dose: Lead with the operated leg, 2–3 sets of 10 on a low step; raise the step height as control improves1
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Stand on One Foot Balance Exercise
Continue until balance matches the other leg, then progress to a cushion or catching a ball as your therapist advises.
Typical dose: Up to 1 minute on the operated leg, near a support; repeat a few times1,2
Want this as a checklist? Turn these exercises into a printable home program with videos and daily check-offs. Adjust the list and doses with your clinician.
Printable handout (PDF, 2 pages). The exercises on this page with typical starting amounts, boxes for your surgical team or physical therapist to write your plan, and a 6-week tracker. Only do what your team has cleared.
Download PDF A4 size Large printEn español: PDF · A4
Watch the exercises
Every exercise above links to its own page with a video and step-by-step instructions. Here are two to start with.
What to expect
These are what published guidance usually says. Your own recovery may be faster or slower.
| Question | What sources say |
|---|---|
| First priority | Full straightening of the knee and a working thigh muscle, before strength and balance work.2,3 |
| How you move between stages | Timescales are a rough guide. Move on when you and your physical therapist agree you are ready. Time since surgery is necessary but not enough on its own.1,4 |
| Normal soreness | Mild aching or stretching for up to 30 minutes after exercise is normal. If pain increases a lot, cut back the reps and how often you exercise, and tell your therapist.3 |
| Returning to running | NHS programs typically start treadmill jogging around 3–4 months. Suggested criteria include full straightening, near-full bend, no swelling and good thigh strength compared with the other leg.1,2,4 |
| Returning to sport | NHS leaflets give about 5–6 months for non-contact sport and 9–12 months or more for contact and pivoting sport, if progress is good. Clearance depends on full movement, no swelling, a stable knee and strength close to the other leg.1,2,3,4 |
What to avoid or change for now
- Resting with a pillow under the knee, and forcing the knee into hyperextension.
- Twisting, pivoting or sudden turns on the operated leg until your team clears you.
- Changing your brace settings or bending past brace limits without your team’s advice.
- Early loaded hamstring or open-chain thigh exercises after a hamstring graft unless your surgeon and therapist include them.
- Starting running, jumping or sport because a date has passed rather than because you meet your therapist’s criteria.
When to get help
- Throbbing pain or swelling in your calf, thigh or groin, sometimes with red or darkened skin, can be a blood clot. Get medical help the same day.1,3,5
- You feel short of breath or have chest pain. Call 911.1,5
- Your knee becomes more swollen, hotter or redder, or you have a raised temperature. This can mean infection; contact your surgical team or get urgent care.1
- Your wound is oozing.1
- New numbness or tingling in your foot, or a change in its color. Get urgent care.1
- Severe pain or excessive swelling in the knee. Contact your surgical team or get urgent care.2,3
For a medical emergency, call 911 (US and Canada), 999 (UK), 000 (Australia) or 112.
Next steps
Related guides: After rotator cuff repair, After shoulder replacement, After an ankle fracture, or see all conditions.
Need a physio or physical therapist? How to find one in the US or UK, including direct access and checking registration.
More exercises: browse the free exercise library, every one with a video.
Frequently asked questions
Why is getting the knee straight so important after ACL surgery?
NHS programs make full straightening the first goal because it is key to walking normally again. Avoid resting with a pillow under the knee, which can make it harder.
When can I stop using crutches after ACL reconstruction?
Usually once you can walk without a limp and take weight with the knee locked straight. Your surgeon may ask for partial weight bearing at first.
Does the type of graft change my rehab?
It can. For example, hamstring grafts may be more sensitive to early loaded hamstring and open-chain exercises than kneecap tendon grafts. Your surgical team’s protocol will say what applies to you.
When can I run or play sport after ACL surgery?
Jogging often starts around 3–4 months, non-contact sport around 5–6 months, and contact or pivoting sport around 9–12 months or later. These steps depend on passing strength and function tests with your physical therapist.
Is this the same as the ACL injury exercise guide?
No. Our ACL injury guide covers prehab and non-surgical rehab. This page is for after reconstruction, when your surgical team’s protocol sets the rules.
Sources
- University Hospitals Sussex NHS Foundation Trust: Physiotherapy advice after your anterior cruciate ligament (ACL) reconstruction (2651)
- King’s College Hospital NHS Foundation Trust: Physiotherapy after ACL reconstruction (PL823.1)
- University Hospitals of Leicester NHS Trust: Advice and exercises after anterior cruciate ligament surgery to your knee
- British Journal of Sports Medicine (BMJ): Aspetar clinical practice guideline on rehabilitation after anterior cruciate ligament reconstruction
- NHS: DVT (deep vein thrombosis)
Last checked October 2026. Found something out of date? Email hello@protocolarchive.com.
This guide summarizes published hospital, health-service and professional-body advice listed under Sources. It is general information, not medical advice, and does not replace an assessment by your own clinician, whose plan may differ for good reasons. Stop an exercise and get advice if it causes sharp or worsening pain. Protocol Archive is independent and is not affiliated with the NHS, AAOS or any hospital or video publisher named on this page.
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