The anterior cruciate ligament (ACL) is one of the strong ligaments within the knee joint that connects the thigh bone to the shin bone (femur to tibia).  The ACL travels from the posterior aspect of the femur to the anterior aspect of the tibial plateau crossing the posterior cruciate ligament hence the name.  An ACL injury can be a partial or complete tear, an avulsion (detachment) from the bone or overstretched.

Along with other ligaments, capsules, tendons and muscles the ACL maintains knee stability allowing free movement of the femur on the tibia in order to bend, straighten, rotate, pivot, jump and hop.  When movement occurs beyond the tolerance of the ACL, injury occurs from a minor strain to complete rupture.  The majority of ACL injuries are due to recreational activities such as football, netball, basketball and skiing with the mechanism being a forced rotation or twist of the knee with the foot fixed on the ground.  Ladies are more likely to injure their ACL than men due to being the fairer sex.

Following an initial period of rest applying the POLICE protocol Muscle Injuries – Fay Pedler ( for soft tissue injuries is essential in allowing the natural healing process to occur.  Investigations such as magnetic resonance imaging (MRI) may be required to corroborate physical examination of ACL injury and any associated cartilage (meniscus) or tendon problems.  Once a decision has been made to either repair with surgery or allow the tissue to heal naturally rehabilitation can begin.

Fay Pedler Physiotherapists are ideally placed to provide the treatment and structured rehabilitation required in order to return the knee to full strength and stability.  ACL injuries require time to settle and committed dedication to recover from.  Unless you are an elite athlete in an elite setting where you are paid to rehabilitate every day you should expect to give yourself 9-12 months to return to your chosen sport.


DVLA guidelines state you must be safe and competent to return to driving.  Could you perform an emergency stop without hesitation?  4-6 weeks is the general guide.

Returning to Work 

Light work such as office job / working from home 4-6 weeks,

Medium physical job 8 weeks,

Heavy manual job (roofs and ladders) 3-4 months plus with phased return.

Initial rehabilitation

Initial aims of treatment are to regain full knee extension (straight knee) in order to encourage tissue (reconstructed tendon graft) to heal at full length and prevent secondary knee joint wear.  Most knee joints will bend to 135 – 140 degrees naturally however in the first 6 weeks following ACL reconstruction surgery the goal is to attain 90° knee flexion.  Swelling / oedema management is vital in the initial stages post-op as a swollen knee will lack movement and be painful further delaying recovery and return to sporting hobbies.

A further goal of the initial period of rehabilitation is to attain a good contraction of the quadriceps muscles to regain knee control through exercises such as bridging, static quad contractions, mini squats and single leg standing balance exercises.