Rehab after ACL reconstruction: the stages to sport

Before surgery: prehab

The best start to ACL rehab happens before the operation. Going into surgery with a calm knee, minimal swelling, full straightening and good quad strength is linked with better outcomes afterwards. That usually means a few weeks of rehab after the injury before surgery, focusing on range of movement, quad activation and general strength.

Our guide to ACL injury covers the injury itself and the decision between surgery and rehab alone.

Prehab is also a chance to prepare practically and mentally. Arrange time off work, help at home for the first week or two, and transport to physio appointments. Learning the first exercises before surgery means you are not trying to master them for the first time while sore and tired from the anaesthetic.

Stage 1: the first two weeks

After surgery, the focus is on protecting the graft, controlling pain and swelling, getting the knee fully straight, starting to bend it, and switching the quadriceps back on. You will usually walk with crutches, weight-bearing as your surgeon advises, and may have a brace depending on your surgeon's protocol and any other procedures, such as a meniscus repair.

1. Quad sets, holding for 5 to 10 seconds, 10 to 20 reps several times a day.
2. Heel propped on a rolled towel to encourage full straightening, a few minutes several times a day.
3. Heel slides to regain bending within the range your surgeon allows.
4. Straight leg raises once there is no lag at the knee.
5. Compression, ice and raising the leg above heart level to manage swelling.

Stage 2: weeks 2 to 12, building strength and control

The aims are to walk normally without crutches, regain full range of movement and build strength and balance. Exercises progress from lying and sitting work to standing strength such as mini squats, step-ups, bridges, calf raises, balance work and the exercise bike. Around this stage, gym exercises such as the leg press and split squats are introduced and progressed.

The type of graft affects the early weeks. Hamstring grafts usually mean a slower progression of hamstring strengthening; patellar tendon grafts can make kneeling and front-of-knee loading sore for a while. Your physio will adjust the programme accordingly.

Typical milestones for the end of this stage include walking without a limp, full straightening, bending to around the same as the other knee, and being able to do single-leg exercises with good control. Swelling after sessions should be minimal. If swelling keeps building, the programme is usually progressing faster than the knee can handle, and it needs adjusting.

It is common for the knee to feel good long before it is strong. The graft is still maturing through this stage, so resist the urge to test it with jumping or twisting just because walking feels normal.

Stage 3: months 3 to 6, running and jumping

Running is usually introduced around 3 to 4 months after surgery, once specific criteria are met: full range of movement, minimal swelling, good quad strength, and pain-free hopping on the spot. It starts with short intervals on a treadmill or flat surface and builds gradually. Our guide to returning to running after injury outlines a typical progression.

Strength work continues to be heavy and progressive, including single-leg exercises such as the single-leg Romanian deadlift, split squats and step-downs. Landing and jumping drills are introduced in stages, from double-leg to single-leg, and from forwards to sideways. Our guide to plyometrics explains how jumping volume should build.

This is often the stage where motivation dips. The knee feels normal day to day, but sport still feels a long way off. Setting short-term goals, such as a strength target or a running distance, and tracking them in a log helps keep the programme on track through the middle months.

Stage 4: month 6 onwards, back to sport

The final stage adds change of direction, agility, sprinting and sport-specific drills, then a gradual return to team training and finally to matches. Return to pivoting sport commonly happens between 9 and 12 months after surgery, and sometimes later. Research has shown that returning before around 9 months, and before passing strength and hop tests, is linked with a higher risk of re-injury.

• Quad and hamstring strength close to the other side, often measured as at least 90 percent
• Hop tests for distance and control close to the other side
• Good landing and cutting mechanics under fatigue
• No swelling or significant pain after training
• Feeling psychologically ready and confident in the knee

Injury prevention work, such as structured warm-ups with landing, balance and strength drills, should continue after you return, since it lowers the risk of a second ACL injury.

Keep strength training in your week for the long term, too. Two sessions of heavy lower-body work alongside your sport helps maintain the strength you worked so hard to rebuild.

Support and when to get urgent help

ACL rehab is a long commitment and it helps to have a clear plan and someone checking your progress against the criteria. The on-site physio at Lycan Strength offers pre and post-operative rehab, and members get 20% off. You can book a physio appointment online.

• Call 999 for chest pain, sudden breathlessness or coughing up blood.
• Contact your surgical team or NHS 111 urgently for a swollen, warm, painful calf.
• Contact your surgical team urgently if the wound becomes red, hot, swollen or leaks, or you have a fever or feel unwell.
• Contact your surgical team if the knee suddenly swells, locks or gives way, or you felt a pop.
• Contact your surgical team if you are not achieving full straightening after a few weeks.

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