ACL Injury: a guide to rehab

An anterior cruciate ligament (ACL) injury to the knee can be a daunting setback, especially for athletes and active individuals. Whether it’s due to a non-contact pivoting movement or a direct blow to the knee, tearing the ACL often leads to pain, instability and a lengthy recovery.

Physiotherapy input in ACL rehab plays a critical role in helping patients regain strength, stability and confidence in their knee. At Physical Health we have a team of excellent physios who work closely with local Orthopaedic surgeons, giving our patients the best joined-up care and rehabilitation.

In this article, we’ll walk you through the key phases of ACL rehab, all the way through to return to sport and hobbies. Outline what to expect during physiotherapy treatment and how to optimise recovery post-surgery or during conservative (non-surgical) treatment.

What is the ACL?

The ACL is one of the four main ligaments in the knee. It connects the femur (thigh bone) to the tibia (shin bone) and helps stabilise the knee, especially during rotational movements. Injuries to the ACL are most common in sports like football, basketball and skiing.

Physio Rehab and Goals of ACL Rehabilitation

1. Restore range of motion (ROM)

2. Reduce swelling and inflammation

3. Regain muscular strength (quadriceps, glutes, calf complex and hamstrings)

4. Improve neuromuscular control and balance

5. Gradually return the patient to sports or everyday activities

6. Prevent future injury (including to the other knee)

If you’re reading this because you’ve sustained an ACL injury, you may choose to read on for more details about post-surgical recovery. If you’re just curious, you might prefer to skip to the summary at the end by clicking here.

PHASES OF ACL PHYSIO REHAB

Phase 1: Prehabilitation (Pre-Surgery)

If surgery is planned, physio starts before the operation, this stage aims to:

• Reduce swelling and inflammation

• Restore near-full ROM

• Strengthen / maintain activity in the surrounding muscles

• Mentally prepare the patient for surgery and the rehab journey

Evidence: studies show that patients who undergo prehab often have better post-surgical outcomes and faster recovery.

Phase 2: Early Post-Surgery (Weeks 0–2) focus areas are:

• Protect the graft site

• Reduce pain and swelling (ice, compression, elevation)

• Begin ROM exercises aiming for full knee extension (heel slides, passive knee extension)

• Start quadriceps activation (e.g., quad sets, straight leg raises)

Tips: Compliance in the first two weeks is critical for long-term success.

Phase 3: Intermediate Recovery (Weeks 3–12) and the goals are:

• Regain full knee ROM

• Improve muscle strength

• Enhance gait (walking pattern)

• Begin closed-chain strengthening (e.g., squats, step-ups)

• Start balance/proprioception training

Key milestones: Walking without a limp, at least 90–120° of knee flexion, good quad control.

Phase 4: Advanced Strengthening (Months 3–6) and the focus shifts to:

• Higher-level functional exercises

• Plyometrics (jumping drills)

• Agility and sport-specific training

• Continued strength building (leg press, lunges, resistance bands)

Physios: often use return-to-sport tests (e.g., hop tests, strength ratios) to track progress.

Phase 5: Return to Sport (6+ Months) - testing time, before returning to sports includes:

• The patient should pass functional tests

• Strength symmetry between legs should be >90%

• The knee should feel stable during cutting, pivoting and sprinting

Even after “clearing” return to play, ongoing maintenance training and injury prevention exercises are essential.

The Role of the Physiotherapist is to guide through this 9-12 month-long process will be:

• Design a personalised rehab plan

• Track your milestones

• Modify exercises to prevent setbacks

• Help you stay positive, motivated and mentally engaged :-)

They’re also critical in helping you avoid common mistakes, such as progressing too fast, ignoring pain or skipping neuromuscular work.

Non-Surgical ACL Rehab

Not every ACL tear needs surgery. Some individuals - especially those who are older, less active, or have a partial tear - may recover well with conservative physiotherapy. In these cases, the focus remains similar: restoring stability, improving strength and function.

Final Thoughts

ACL rehabilitation is a marathon, not a sprint. Whether you're an athlete aiming to return to the field or someone who just wants to walk pain-free again, physiotherapy is the cornerstone of recovery. With dedication, expert guidance and a structured program, most people can return to their pre-injury activities - and sometimes stronger, both physically and mentally, than before.

If you're recovering from an ACL injury, you can talk to one of our physiotherapists about building a tailored rehab plan on 01932 645320 or emailing info@physicalhealth.co.uk. Early intervention and consistent care make all the difference.