Doing these exercises before your operation will help you to regain full range of movement, reduce the swelling and restore strength back into the muscles and help you recover after your surgery.
The below video is a step by step guide of the exercises to strengthen and prepare your knee. These are also some of the exercises you will be asked to continue after your operation. You should aim to perform these exercises 3 to 4 times a day, but this will be guided by the physiotherapy team.
Exercise Guidelines After ACL Injury or Surgery
These exercises will be demonstrated to you on the ward and reinforced during your first physiotherapy appointment. They can be progressed or maintained at your current level until your function improves.
One of the key exercises to focus on after an ACL injury or surgery is achieving knee extension (straightening). To do this, comfortably place a rolled towel under the back of your knee, not too high. Aim to apply tension in your quadriceps muscle. You may or may not see your heel lift off the bed, depending on your usual range of motion. If you have difficulty activating your quadriceps due to swelling or a nerve block, a helpful cue is to sit on your hand while trying to tighten the muscle and gently press down into the towel. This will help engage the quadriceps.
When you tighten the muscle, aim for your kneecap (patella) to pull gently upwards. This exercise should be performed as soon as it is comfortable, three to four times per day. You can do this for timed intervals or for a set number of repetitions, as explained on the ward.
Another important exercise is knee flexion (bending). You can use a towel on a sliding surface or place a plastic bag under your foot to assist. Pull your foot toward you to work on bending your knee within the range allowed. If you have a meniscal injury, you may be restricted to 90 degrees of flexion, as indicated by your brace. For an isolated ACL injury, aim for as much comfortable bend as possible. When straightening your knee, combine this movement with tightening your quadriceps and pulling your toes toward you to stretch your calf muscle.
In cases where achieving full extension is challenging, consider placing your leg on a table, chair, or block to create space between your knee and the bed.
Gravity can assist in straightening your knee. It may be uncomfortable to hold this position for more than 10 to 15 minutes, so change positions as needed.
While in this position, tighten your quadriceps to enhance the stretch.
Additionally, you can perform a gentle calf stretch by holding it for 15 to 20 seconds, releasing, and repeating as comfort allows. The frequency of these exercises will be guided by the physiotherapists on the ward or during your outpatient appointments.
Early on after ACL reconstruction, it’s also important to activate your hamstrings. To do this, bend your knee and gently press your heel into the bed until you feel tension build in the hamstring area. This can be done until you feel fatigued, aiming for 10 to 15 repetitions, with each contraction lasting about 10 seconds.
For static quadriceps activation, you can resist with your uninjured leg. Apply tension by pushing your uninjured leg forward while meeting the resistance in the middle. This exercise helps activate your quadriceps and is safe to perform in the post-operative phase. Hold the contraction for up to 10 seconds, progressing to 10 to 15 repetitions as tolerated.
A simple inner range quadriceps exercise can also aid in extension. Place a ball, rolled towel, or pillow under your knee, tighten your quadriceps, and gently press back into the ball. Hold for up to 10 seconds and repeat 10 to 15 times. Be mindful not to rotate your hip backward and push the middle of your foot into the floor to ensure proper muscle activation.
To stabilize the lower leg after surgery or injury, practice calf raises by rising onto your tiptoes while keeping your knees straight. Lower your body weight slowly, ensuring that your hips do not swing forward and that you distribute your weight evenly between both legs.
Another beneficial exercise is the knee lock-unlock or mini squat. Allow your knee to soften to take tension out of the straightened position, bending to about 30 degrees on both sides before slowly returning to a straight position by tightening the muscles. Avoid quickly snapping your knee back; control the movement by increasing tension in the front knee muscles and pressing your foot into the floor.
As you progress, try these exercises on your operated leg. Allow tension to ease off when straightening, and do not bend too far forward. Aim for 10 to 15 repetitions, which can also help improve balance and proprioception after your injury.
Breathing exercises
Practice deep breathing exercises to reduce your risk of developing a chest infection. Regardless of your age and general fitness before your surgery, you are at risk of developing a chest infection, as it can take a while for your lungs to return to normal after the anaesthetic. You can do this by taking a deep breath in, holding it for three seconds and then breathing out. Aim to do at least five of these every hour.
Strength and conditioning
As part of your recovery you may meet our Strength and Conditioning coaches who support patients from 12 weeks after their surgery to keep building strength in their operated knee and to resume any previous activities and sports. Find our more using the video below.
Meet our Strength & Conditioning coach
Strength and Conditioning After ACL Reconstruction
Hi, I’m Harry, the strength and conditioning coach at Leeds Station Hospitals. Patients can be referred to me any time after the 12-week mark. Transitioning to strength and conditioning means moving from more general strengthening exercises to specific, individualized programs tailored to your end goals. The timeline and exercise types will vary from patient to patient, depending on individual needs.
Initially, we will conduct strength tests to ensure symmetry between your operated and non-operated limbs. Our goal is to achieve at least 80% symmetry in strength, which will help you progress to low-level plyometrics. This includes hopping and some directional hops to prepare your knee for increased impact.
After establishing a baseline with strength testing, we will perform plyometric tests, again aiming for above 80% symmetry between both limbs. Following this, we will implement return-to-play strategies. If you’re not returning to sports, we will focus on getting you back to your usual activities.
We’ll introduce high-level plyometrics and gradually increase the intensity of the exercises, providing you with a guided program to follow independently. The timeline for recovery from surgery to discharge or return to play can range from 9 to 12 months after ACL reconstruction. While we understand the desire to return to sports as soon as possible, research shows that returning within the nine-month mark can increase the risk of re-injury by seven times. Therefore, it’s essential to take the necessary time and focus on a controlled return to play, which will help reduce the risk of re-injury.