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Torn ACL? Guarantee best recovery with these pre-op exercises for anterior cruciate ligament injury

Updated: Feb 18, 2023

The anterior cruciate ligament is a very important ligament in the knee and is usually injured when a player forcefully rotates his leg with his foot planted in the ground - often combined with a blow to the knee from the knee or foot of another player.

What exercises works best for a torn ACL?

A full tear requires surgery and the recovery time can take anything from 9 to 12 months. Anterior cruciate ligament (ACL) injuries can have very poor recovery rates despite surgical repair. A recent review of the literature found that only 55% of players return to competitive sports after an ACL rupture and only 61% to their pre-injury level of sport.

In this post:

  • Improve your chances for recovery from an anterior cruciate ligament injury

  • Potential problems with the research

  • Treatment for a torn ACL

  • Pre-op exercise programme for a torn ACL

  • Post-op exercise programme for a torn ACL

Improve your chances for recovery from an anterior cruciate ligament injury

What if you could do something before and after surgery to improve the results of your ACL reconstruction? This is the question a group of Norwegian researchers (2) recently tried to answer. They compared the knee function in two different patient groups before and 2 years after ACL reconstructive surgery.

Group 1 included patients who underwent treatment and rehabilitation at a sports injury clinic. They underwent an intense 5 week exercise programme BEFORE surgery with the aim to regain at least 90% of their hamstring and quadriceps strength and hop performance. They also received an individually tailored exercise programme after surgery.

Group 2 included patients in the Norwegian national registry who received ‘usual care’. The rehabilitation group (Group 1) not only reported better knee function immediately after surgery but also at a 2 year follow-up!

Image of the knee joint and ligaments. The anterior cruciate ligament is located in the middle of the knee.

Potential problems with the research

The researchers unfortunately did not elaborate on the details of the ‘usual care’, so it is impossible to tell if the specific rehab programme was indeed superior. It may very well have been a lack of adherence to any exercise programme that led to a worse outcome in Group 2.

One can also assume that the patients attending the sports clinic may have been less likely to smoke which could have contributed to their superior results. A previous study using the same cohort of 22 000 patients as used in Group 2, found that smoking led to significantly poorer outcomes after surgery.

The results from this study are, however, backed up by other studies that have found that strengthening the muscles around the knee, especially the quadriceps, can lead to superior knee function after ACL surgery.

The authors do point out that the superior results may also have been due to other advantages of being treated at a specialised sports injury clinic e.g. quality education, attention to psychological issues during the rehabilitation process and taking part in supervised goal orientated programmes. One could also argue that patients attending sports clinics may be more motivated to do their exercises.

But there is no arguing about the fact that their exercise programme produced good results, so it is worth taking a look at what they did.

Pre-op treatment for a torn ACL

The pre-op treatment programme in this study was divided into 2 phases.

Phase 1 pre-op

Phase 1 commenced immediately after the person tore their ACL. The aims during this period were:

1. To regain full range of motion in the knee

2. To decrease swelling in the knee

As soon as the swelling inside the joint was resolved and the knee regained full range of motion, Phase 2 was implemented. It took the study participants roughly 60 days after they injured their anterior cruciate ligaments to move from Phase 1 to Phase 2.

Treatment during this phase:

  • Use ice often during the day. Apply it for 10 minutes around the knee joint. Remove it for 10 minutes and then reapply it again. I find a packet of peas works best – it’s easy to shape around the knee and gets very cold. You can read more about how to use ice to treat injuries here.

  • Do gentle movements with your knee often during the day. Try to bend it up as far as you can and then to straighten it out fully. Do not push into pain, but rather just move it to where you can feel the discomfort kicking in. Repeat this up to 20 times in one go and do it every two hours. This should not make your knee hurt or swell more.

  • Activate your quadriceps muscles: Tense your quadriceps muscle for 10 seconds and relax. Repeat 10 times every hour. Progress this to lifting your straight leg into the air about 20cm above the bed and holding the position for 10sec.

  • Do not spend too much time on your feet and use a crutch or stick if you go for long walks. Reducing the weight through the joint during the initial few weeks will help to reduce the swelling.

Phase 2 pre-op

The main aims during Phase 2 were to regain muscle strength and control.

They interestingly included both open and closed chain exercises. An example of an open chain exercise is the knee extension machine. The ‘open chain’ refers to the fact that the foot is free and moves during the exercise. An example of a closed chain exercise is the squat. During this exercise the foot is planted and stays still throughout the movement – the chain is thus closed.

Back in the day when I was a student we were taught to avoid open chain knee extension e.g. with the knee extension machines, since this was thought to put too much strain on the torn ACL. Research has now shown that this is actually not the case and that these exercises are safe and beneficial for ACL injuries. This is a good example of why physios should keep up to date with the latest research!

They also included plyometric training in the form of hops and jumps, but I would suggest that you only do this if a physiotherapist has examined you and told you it is safe to do so. The only adverse effects reported during the study was as a result of the plyometric exercises. It caused a worsening of pain and swelling in 4 of the participants.

Pre-op exercises for torn ACL

The exercise regime used during Phase 2 of the study consisted of:

  • A 15 minute warm-up on the cross trainer or stationary bike

  • Lasted for a maximum of 75 minutes

  • Exercises were aimed at strengthening the quadriceps and hamstring muscles and included the leg press, leg curl and knee extension machines as well as variations of the squat and glute bridge.

  • A minimum of 2 and a maximum of 4 exercise sessions per week

  • 3 to 4 sets of an exercise

  • 6 to 8 repetitions

  • The exercise intensity was progressed using the +2 principle. A person was instructed to do as many reps as they could during the final (3rd or 4th sets) set of an exercise. If they could do 2 extra reps during the last set, the load was increased during the next training session.

  • They did include plyometric exercises that aimed to develop soft landings and controlling the knee-over-toe position, but please be careful with these.

  • Balance exercises were progressed from standing on a stable object e.g. one leg balance on the floor to using roller boards or doing single squats on balance pads.

  • The exercises were tailored to the specific needs of each patient and slowly progressed.

  • I would advise that you start with light weight exercises and make sure that you control them properly like they did during the post-op period below. You should not feel pain during or after exercising and your knee should not swell after exercise.

Post-op exercises for torn ACL

The post-op treatment regime was divided into 3 phases. They used the same exercises and progression as with the pre-op programme, but added a third phase during which they did specific drills to prepare the athletes for their sport.

Phase 1 post-op

Your surgeon will give you specific guidelines to follow during this period but your aims are very much the same as during Phase 1 of the pre-op phase:

  • Regain full range of motion

  • Decrease swelling

  • Prevent muscle atrophy

You can find detailed exercises for post-op rehabilitation of an ACL here.

Phase 2 post-op

This phase lasts between 2 to 6 months post surgery. Your aims during this phase should be:

  • to regain full control of weight-bearing terminal knee extension

  • regain at least 80% muscle strength and hopping ability

The strength training was initiated with two sets of 30 repetitions (low load) and gradually progressed to four sets of 4–6 repetitions (high load). Plyometric exercises were introduced once the strength training progressed to high load (typically 4 months postoperatively). The intensity of the exercises were increased according to the guidelines above.

Phase 3 post-op

The third phase lasted roughly from 6 to 12 months post-op. The aims during this phase included:

  • was to regain at least 90% muscle strength and hopping ability

  • to enable the transition to sport

This phase consisted of heavy resistance strength training and increasingly demanding plyometric exercises, as well as sport-specific drills.

Need more help with your injury? You’re welcome to consult one of the team at SIP online via video call for an assessment of your injury and a tailored treatment plan.

About the Author

Maryke Louw is a chartered physiotherapist with more than 15 years' experience and a Masters Degree in Sports Injury Management. Follow her on LinkedIn or ReasearchGate.


  1. Perry, M., Morrissey, M., Morrissey, D., Knight, P., McAuliffe, T., & King, J. (2005). Knee extensors kinetic chain training in anterior cruciate ligament deficiency. Knee Surgery, Sports Traumatology, Arthroscopy, 13(8), 638-648.

  2. Grindem, H., Granan, L. P., Risberg, M. A., Engebretsen, L., Snyder-Mackler, L., & Eitzen, I. (2015). How does a combined preoperative and postoperative rehabilitation programme influence the outcome of ACL reconstruction 2 years after surgery? A comparison between patients in the Delaware-Oslo ACL Cohort and the Norwegian National Knee Ligament Registry. British Journal of Sports Medicine, 49(6), 385-389.

  3. Granan, L. P., Forssblad, M., Lind, M., & Engebretsen, L. (2009). The Scandinavian ACL registries 2004–2007: baseline epidemiology: Acta Orthop. 2009 Oct 1;80(5):563-7. Epub 2009 Oct 1 doi:10.3109/17453670903350107.

  4. Eitzen, I., Moksnes, H., Snyder-Mackler, L., & Risberg, M. A. (2010). A Progressive 5-Week Exercise Therapy Program Leads to Significant Improvement in Knee Function Early After Anterior Cruciate Ligament Injury. Journal of Orthopaedic & Sports Physical Therapy, 40(11), 705-721.

  5. Ardern, C. L., Taylor, N. F., Feller, J. A., & Webster, K. E. (2014). Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. British Journal of Sports Medicine, 48(21), 1543-1552.


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