Altitude logo

ACL Knee Injury

What is the ACL?

The ACL (anterior cruciate ligament) is one of four main ligaments that stabilise the knee the joint. The ACL runs diagonally in the middle of the knee. It prevents the tibia from sliding out in front of the femur, as well as providing rotational stability to the knee.

How does an ACL injury occur?

ACL injuries can occur by landing after a jump, pivoting or decelerating suddenly. A large force behind the knee joint can also cause an ACL injury.  Other knee injuries such as damage to the meniscus (knee cartilage), and the medial or lateral collateral ligaments may also accompany a torn ACL.


Immediate management

Immediate treatment of an ACL injury involves the RICER protocol for 48-72hours post injury to reduce bleeding, damage and swelling within the joint. RICER stands for:

·        Rest

·        Ice

·        Compression

·        Elevation

·        Referral

Rest the injured knee in an elevated position with an ice pack wrapped in a towel applied for 20minutes every 2 hours. Avoid heat, alcohol, running, and massage. A MRI test may be recommended to confirm diagnosis.


Will you need surgery?

Depending on the severity of the ACL injury, surgical reconstruction is a method used to repair an ACL. Factors that are considered when deciding on whether to surgically reconstruct a torn ACL include:

·        Knee instability

·        Associated injuries of the knee

·        Type of sports played 

·        Age


Pre-surgery rehabilitation:

Pre-surgery rehabilitation before surgical reconstruction of the ACL decreases the chances of further injury to the knee and greatly influences the chances of a successful surgery. Goals of pre-operative rehabilitation include:

·         Restoring full range of motion (knee bend & straightening)

·         Strengthening the muscles around the knee joint to match uninjured knee

·         Increasing coordination (neuro-muscular control) of the knee.


Post-surgery Rehabilitation Stages:

Phase 1: Acute Recovery

·         Wound healing

·         Minimise swelling & inflammation

·         Restore range of motion

·         Muscle strengthening and control


Phase 2: Mid Stage

·         Further develop muscle strength and control

·         Commence running based activities

·         Develop muscle endurance


Phase 3: End State – Return to play

·         Develop explosive power, speed, agility & muscular endurance 

·         Return to play with minimisation of re-injury risk.


How long until I can return to sport?

Return to normal functional activities can take between 6-9months. Safe return to sport is recommended at the discretion of the physiotherapist and surgeon, but is generally in excess of 12months post-surgery.


Sport specific injury prevent programs available online:

·         Netball -

·         Soccer -

·         AFL -

·         Rugby -


I'm a paragraph. Click here to add your own text and edit me. It's easy.

Child Physiotherapy
Rugby Players


1.        ACL Reconstruction – Hamstring Autograft. (n.d.) Retrieved from

2.        Anterior cruciate ligament injuries. (2017). Retrieved from

3.        Anterior cruciate ligament (ACL) injuries. (2014). Retrieved from

4.        Awad, O. B., Alqarni, S. A. Alkhalaf, H. M., Alnemer, F. A., Alhamari, K. A., Alshahrani, S. M., … Dowaikh, A. M. (2017). A Systematic Review of ACL Reconstruction Rehabilitation. Egypt J Hosp Med. 68:845-864. Doi: 10.12816/0038184

5.        Biggs, A., Jenkins, W. L., Urch, S. E., & Shelbourne. K. D. (2009). Rehabilitation for Patient’s Following ACL Reconstruction: A Knee Symmetry Model. N Am J Sports Phys Ther. 4(1):2-12. Retrieved from

6.        Brunker, P., & Kahn K. (2017). Clinical Sports Medicine: Volume 1 Injuries. Sydney, NSW: McGraw Hill Education

7.        Giannakis, J. R. (2018). Post-operative rehabilitation protocols for anterior cruciate ligament injuries. JASC. 26(02):58-68

8.        Kim, D. K., Hwang, J. H., Park, W. H. (2015). Effects of 4 weeks of preoperative exercise of knee extensor strength after anterior cruciate ligament reconstruction. J Phys Ther Sci. 27:2693-2696.

Pinczewski, L., Roe, J., Lyons, M., Gooden, B., Salmon, L., & Heath, E. (2018, June). ACL rehabilitation. North Sydney Orthopaedic Research Group. Retrieved from