St Ives Clinical Physio - ACL injury

ACL Rehabilitation

“Up to 30% of athletes will suffer a second ACL injury within 24 months of return to sport and will require ACL Rehabilitation”

Want to give yourself the best chance of a successful return to sport? Email us to enquire about our discounted 1 Year Physio Membership

Understanding ACL Injuries

What is the ACL?

The Anterior Cruciate Ligament or ACL is one of the primary stabilising ligaments in the knee. The ACL originates from the thighbone (femur) and connects to the shinbone (tibia). The primary role of the ligament is to stabilise the knee during sudden acceleration/deceleration forces and change of direction movements during high impact sport and exercise. Its main role is to prevent anterior movement or translation of the tibia in relation to the femur.

How does an ACL Injury occur?

An ACL injury is a highly common injury normally associated with high speed and agility or change of direction in sports such as Australian football, rugby union, rugby league, netball, basketball, soccer, skiing, touch football etc. Typically there is a valgus/twisting force where the knee collapses and rotates inwards.

The most common ACL injury is a complete rupture. This is normally associated with immediate intense pain and swelling, hearing a loud sound such as a “pop” or “crack” during the activity or trauma, knee instability, giving way and damage to other structures within the knee.

How is an ACL Injury Diagnosed?

An ACL injury is most accurately diagnosed with a history a clinically significant Mechanism of Injury (MOI), such as twisting and hearing a “pop”, as described before along with various clinical tests.

These clinical tests can be performed by an experienced and skilled health professional such as a Physiotherapist, Sports Doctor etc.

These tests are called the Lachman’s, Anterior Drawer, Pivot test and Lever’s sign.

If an ACL injury is suspected, the diagnosis is confirmed by Magnetic Resonance Imaging (MRI) which may be referred by your GP, Knee Specialist or Sports Physician. Physiotherapists can refer for MRI’s, however there is no medicare rebate so you will be out-of-pocket about $310.


Is Surgery Always required?

Although surgical reconstruction is the most common method of recovery it is not always required to return to a good quality of life, high-level functioning and return to sport. There is some evidence emerging now that might mean there is a proportion of the population might be able to return to a high level of play without requiring surgery. ​In fact, a study in 2017 involving 102 athletes, found that 72% actually healed by themselves after 12 months, without surgery.

Are they common?

Current research is showing that Australia has the highest incidence of anterior cruciate ligament injuries in the world. This is approximately 200 000 ACL reconstructions occurring in fifteen years from 2000-2015 which is a 70% increase in incidence.

What to do next if you have been diagnosed with an ACL Tear?

Talk with your physio and your specialist to determine if surgery is the right course of action.
The current indications for surgery are:
1) If you have concurrent injuries to other structures in the knee e.g MCL, meniscus, posterolateral corner
2) If you would like to return to high level pivoting sports.


​If, however, you have no other damage to the knee and you are not planning on a return to a high level of sport, then a conservative, non-surgical approach may be the best course of action.


How important is rehabilitation?

Up to 30% of people under the age of 20 will go on to sustain a 2nd ACL injury within 2 years upon to RTS. A comprehensive 12 month rehabilitation program can reduce this risk by 50%.

Rehabilitation Guidelines

Rehabilitation prior to surgery/intervention is essential for improved outcomes following Anterior Cruciate Ligament (ACL) Reconstruction surgery. Your knee incurs deficits in terms of strength, proprioception (the ability to maintain balance), muscle timing and gait (walking patterns) after suffering an ACL injury. Physiotherapy has been shown to reduce episodes of ‘giving way’ and decrease the chances of re-injury of the ACL through the improvement of strength and balance. The goals of pre-operative rehabilitation include:

  • Restoring full range of motion
  • Achieve adequate neuro-muscular control
  • Strengthening muscles that are important in post-operative rehabilitation
  • Understand what types of exercises must be completed in post-operative rehabilitation
St Ives Clinical Physio - ACL injury

Pre Operative Rehabilitation

Rehabilitation prior to surgery/intervention is essential for improved outcomes following Anterior Cruciate Ligament (ACL) Reconstruction surgery. Your knee incurs deficits in terms of strength, proprioception (the ability to maintain balance), muscle timing and gait (walking patterns) after suffering an ACL injury.

Physiotherapy has been shown to reduce episodes of ‘giving way’ and decrease the chances of re-injury of the ACL through the improvement of strength and balance.

Post Operative Rehabilitation

A comprehensive rehabilitation programme guided by a Surgeon and physiotherapist will enhance recovery following surgery and facilitate return to sport/Exercise. General aspects of the post-operative rehabilitation and goals are listed below:

Range of Motion (ROM)

Restoring pre-injury range of motion improves surgical outcomes and minimises the chances of scarring within the knee. There is a particular focus on restoring full knee extension early

Walking and running gait
  • Muscle imbalances/dysfunction is common in the early stages following ACL reconstructive surgery. This leads to altered gait mechanics with reductions in stride length, altered swing and stance phases together with weak/uncoordinated firing of hip, knee and ankle musculature.
  • Early weight bearing attempts to restore gait mechanics in a timely fashion and reduce the incidence of anterior knee pain.
  • Treadmill rehabilitation (mid-stage) is a good way of normalising joint motion of the lower limb. Backwards walking in particular, strengthens the quadriceps while minimising anterior knee pain. This also provides for sport-specific training requiring backward locomotion.
Muscle strengthening and endurance training

Muscle contains Type 1 (endurance) and Type 2 (fast-twitch) fibres in varying amounts. Following ACL injury, these fibres show signs of atrophy (wasting away) and changes in cellular composition. Therefore, ACL rehabilitation requires focus on both these different types of fibres namely; low-load/high repetitions (endurance) and high-load/low repetitions (strength)

Exercise quality is key
  • It is imperative NOT to begin new exercises prior to neuromuscular readiness.
  • If certain muscle groups remain weak, this leads to compensation which in turn produce faulty movement patterns. If these faults are not corrected, this may perpetuate the original weakness.
Neuromuscular/Proprioceptive retraining

Neuromuscular control is often altered following ACL injury and surgery. Specific exercises activate receptors within the knee joint which in turn trigger compensatory muscle activation patterns to aid knee stability. These exercises should commence early following surgery to promote neuromuscular integration which help with gait training and muscle strengthening. Functional outcomes highly correlate with balance and proprioception following ACL reconstruction.

St Ives Clinical Physio - ACL injury
St Ives Clinical Physio - ACL injury

Stages of Rehabilitation

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

Weeks 0-2


  • Manage Pain and post operative swelling
  • Establish Range of motion (0-90°, Full Extension a priority)
  • Retrain gait pattern
  • Re-establish muscular control of quadriceps, hamstrings and calves

Exercise examples

  • Inner range quadricep contractions
  • Calf raises
  • Hamstring contractions/gentle heel digs
  • 1/4 isometric squats
Weeks 2-6


  • Progress to full knee flexion and extension
  • Achieve normal walking gait pattern
  • Progress balance/proprioception

Range of motion

  • Prone assisted knee flexion and extension​
  • Assisted quadriceps stretching exercises (standing)
  • Heel slides and exercise bike (allow full circles forward & backward)
  • Muscles

    • Quadriceps

      • Closed chain exercises such as assisted squats/leg press/step ups

    • Hamstrings ​

      • bridging 

    • Gluteals

      • bridging, side lying abduction

    • Calves

      • Calf raises

    • Proprioception

      • Single leg balance

    • Gait

      • Progress to unassisted full weight bearing

      • Exaggerate hip and knee flexion during swing phase of gait

    • Cardiovascular

      • Exercise bike

      • Start elliptical trainer

Weeks 6-9
  • Goals 

    • ​​To achieve full, pain free range of motion

    • Begin limited/specific isokinetic quadriceps exercises

  • ROM

    • Achieve full knee flexion and extension

    • Continue hamstring and calf stretches

  • Muscles 

    • Quadriceps

      • Can start full squats and lunges

    • Hamstrings

      • Progress bridging, curls, RDL’s

    • Gluteals

      • Advance on all direction strengthening (ankle weights, resistance cables)

    • Calves

      • Advance on all direction strengthening (ankle weights, resistance cables)

    • Proprioception

      • Single leg stance on mini-trampoline

      • Upper body work (throwing)

      • Floor disc squatting & throwing

      • Wobble board (balance)

    • Gait

      • Hydrotherapy sessions:

        • Knee ROM

        • walking (all directions)

        • hip ROM

    • Cardiovascular

      • Exercise bike (increasing time & resistance)

      • Swimming (flutter kick only)

      • Pool jogging

      • Treadmill (Walking. Avoid jogging)

Weeks 9-12
  • Goals

    • Progressive quadriceps & hamstring strengthening, proprioception and flexibility

  • ROM

    • Continue stretches as before ensuring achievement of full knee range of motion Muscles

    • Quadriceps

      • Dynamic lunges ensuring proper truncal alignment,

      • backward step-ups, eccentric step downs (20cm)

      • single leg squats

      • low resistance jumping (2 legs, then jogging, then single leg hops)

      • progress with isokinetic programme

    • Hamstrings

      • Hamstring curls (in the standing, sitting and prone position) with increasing resistance as tolerated, eccentric hamstring rehabilitation

    • Gluteals

      • Progress as before

    • Calves

      • Eccentric heel drops

    • Proprioception

      • Catching & throwing exercises on wobble boards & mini-trampoline.

      • Single leg stance on a floor disc (kicking drills, upper body skills)

    • Cardiovascular

      • Pool running (increasing time and repetitions)

      • Exercise bike (increasing time & resistance)

      • Treadmill (incline walk and increase speed. Avoid jogging)​

Weeks 12-16
  • Goals

    • Continue flexibility and strengthening of the lower chain

    • Commence sport specific quadriceps/hamstring strengthening, proprioception & cardio fitness

  • Muscles

    • Continue concentric & eccentric quadriceps and hamstring exercises.

    • Backward lunge walking.

    • Progress from jogging to running.

    • Split squat jumps.

    • Single leg drop landing (5cm)

  • Proprioception & Agility

    • Ladder drills (forwards/backwards/side-to-side)

    • Side step-overs (progressing to side step-overs)

    • Skipping and hopping (2 legs progressing to single leg)

    • Mini-trampoline (2 feet jumps – jogging – single leg jumps)

    • Continue single leg floor disc exercises (aim for sport specific activities. Eg: kicking, hockey shot, cricket batting etc.)

  • Cardiovascular

    • Pool hopping and squat jumping (in shallow water)

    • Jogging (straight on flat, even ground. Avoid sudden cuts/change of direction)

    • Treadmill jogging progressing to running

    • Sport specific cardio training​

Weeks 16 - 26
  • Goals

    • Sport specific lower chain strengthening and progress to plyometric exercises

    • Continue proprioceptive & cardiovascular fitness

  • Muscles

    • Progress as before concentrating on specific deficits on muscle groups (if any arise)

  • Proprioception

    • Progress on mini-trampoline

    • Forward & side hops (maintain 5 second single leg balance on landing)

    • Cutting drills (quick stop & balance)

  • Agility & Plyometrics

    • Ladder drills (all directions)

    • Progress on running/lunging/vertical jumps/run-stop-sidestep

    • Single leg forward & side hopping.

    • Single leg jumps o Box hops/jump and forward sprints 

    • Single leg drop landing (progressive up to 25cm)

  • Cardiovascular

    • Increase intensity on bike/treadmill/jogging

    • Progress from running to sprinting (ensure proper rhythmic stride)

    • Jogging with directional change/uneven surface

    • Jogging with turns 90/180/360°

    • Jogging and cutting with 45° change of direction

    • Acceleration and deceleration running, add on tight turns and hills as tolerated

    • Outdoor cycling

    • Swimming (avoid the ‘whip-kick’)

Month 6-9
  • Goals

    • Excellent fitness, strength, power, agility neuromuscular control, symmetry and stability

    • Sport specific practice

  • Exercise Suggestions ​

    • Last minute decision drills

    • Single limb drop landing (at least within 10% of uninvolved side)

Months 10-12

Return to full training. No games until completed 6 weeks of full training and game simulation.

Return to Sport Testing
  • Single limb hop for distance 

  • Single-limb crossover triple hop for distance 

  • Single-limb timed hop over 6m

  • T-test