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Anterior Cruciate Ligament (ACL) Rehab (updated August 2011)


Anterior Cruciate Ligament (ACL) Rehab (updated August 2011)


Updated August 2011

Melanie McNeal, PT, CSCS, CFT
for patients of

The ACL is the primary restraint to anterior tibial translation from 50-0° of knee extension. Approximately 3cm in length, it runs from a narrow insertion on the lateral femoral condyle to a more broad, diamond-shaped insertion anterior to the intercondylar eminence of the tibia.

Sixty-six percent of ACL tears are non-contact in nature. This can occur from deceleration, such as when landing from a jump , or cutting activities which force the knee into excessive flexion, valgus, and rotation. Bone bruises are present in 60-80% of ACL tears, causing excessive pain with increased weight bearing. This should be taken into account when prescribing a rehab program.

It is a well-known fact that females suffer more ACL injuries than males in the same sport. This has been attributed to numerous factors including the following differences between males and females:

  1. Anatomy: females have a wider pelvis, increased flexibility, narrower femoral notch, increased genu valgum, and increased tibial torsion
  2. Neuromuscular function: females have difficulty recruiting their hamstrings to provide co-contraction with the quads for dynamic stabilization – this can be seen when landing from jumps (females land with 3x less knee flexion than males) and during cutting maneuvers. Females have longer electromechanical delay compared to males. Females require more time to produce force levels compared to males. Females’ knees are more lax than males and this laxity increases 50% during the menstrual cycle. Females generally have increased recurvatum, which puts the hamstrings at a mechanical disadvantage to provide stability.

These differences have important implications for the female during the rehab process. It is imperative that the therapist teaches the patient to control valgus movements at the knee during exercise and ambulation. Keeping the knee over the second toe during all closed kinetic chain activities is imperative. The therapist must also work to retrain recruitment patterns so that the patient learns to co-contract the hamstring and quads. Important activities that heavily recruit the hamstrings are lateral lunges, multi-planar activities, A-P movements using a tilt board, plyoball activities, and bounding. Isolated hamstring strengthening should also be performed. It is important to teach the patient the proper way to land from a jump. The knees should flex to about 30° of knee flexion since this is the angle with the greatest HS/Quad co-activation. This angle should be achieved during other exercises as well, such as landing from a lunge or step-up or when performing single leg balance activities.

Graft Choices: It is also important to consider the type of ACL graft utilized. Patients who have received an allograft tend to have less pain and swelling but tend to stretch out more frequently. It must be stressed to these patients that it takes longer for the body to incorporate tissue that is not its own, and that even though they may feel “normal”, protection of the graft is vital by progressing slowly and avoiding stress to the graft.

Patella tendon grafts are usually utilized with high-level athletes that need to return to sport ASAP. These grafts tend to be more painful and it is common to experience pain with kneeling for a prolonged period as well as patellar tendonitis during the rehab process. Because of the bone to bone fixation, however, rehab can be advanced aggressively.

Another common graft of choice for Dr. Lintner is the hamstring graft using a doubled semitendinosus and gracilis tendon. The graft is as strong as the patella tendon graft, but does not have bone on it. This slows the attachment to the bones in the knee, but has the benefit of less post-operative pain. The hamstring tendons usually regrow, and when they don’t the remaining three get stronger to cover for those harvested. The main problem with hamstring grafts is some weakness with deep knee flexion. This can be troublesome for athletes that must backpedal (defensive backs in football) or pull their foot up to their buttock (hurdlers, gymnasts).

Allograft (donor grafts) are becoming popular. They are strong, and do not involve any additional trauma to the knee. So the early recovery is faster. But, the ingrowth of the graft to the bones is slowest with this graft. This is most popular with older or petite patients.

Rehab is the same for patella tendon grafts and hamstring grafts. Isolated active-resistive hamstring activity can be initiated immediately even if the patient had a hamstring graft. For both patient groups, isotonic knee extensions should be avoided at least 6 months to avoid stress to the graft.

Return to Play: the graft takes about 6 months to mature enough to tolerate the forces generated in most sports. Plus, the athlete must have achieved the physical performance goals as well (agility, jump training, etc).

A home exercise program is critical and should be emphasized heavily to the patient, especially initially. The more the patient does at home, the faster recovery will be. The first few days after surgery are focused on minimizing swelling while stimulating the quadricep.


Weeks 1-2

The patient will be in a post-op IROM brace that is set at 0-90 degrees. The brace is to be worn at all times except when exercising, in bed, or in the CPM machine. The patient should ambulate with B axillary crutches and brace until a N gait is achieved.

Dressing will be intact – do not remove initially to decrease probability of infection. Once stitches have been removed, ok to remove elastic wrap.

Keys during phase one:

  • Gain full knee extension so patient can ambulate with N gait.
  • Neuro-muscular quad control – use biofeedback on VMO
  • Control swelling: Swelling inhibits quad firing and limits ROM; as long as there is a flexed knee gait, the more the patient ambulates, the more swelling will increase; therefore, limit activities and ambulation early in rehab.
  • Normal gait: patients will ambulate with flexed knee gait secondary to no quad control; have patient focus on quad contraction and full knee extension during stance phase of gait
  • ROM: In surgery, full ROM is achieved after the graft is fixated to assure has been correctly placed; ROM should be progressed as tolerated.


  • Quad sets (10 X 10sec)– the more the better – at least 100/day
  • SLR – 4 way
  • Multi-hip
  • Calf Raises
  • Shuttle/Total Gym


  • Hamstring stretch (not aggressive if HSG) – hold 30 seconds
  • Gastroc stretch with towel – hold 30 seconds
  • Prop foot on pillow to encourage full extension
  • Prone hangs to gain full extension


  • Goal during this phase is 0-110° at least
  • Manual patella mobs – especially superior/inferior
  • Seated heel slides using towel
  • Supine heel slides at wall if needed
  • Prone hangs if needed to gain full extension
  • Bicycle – do not perform until 110° of flexion is achieved – do NOT use bike to gain ROM. Perform daily and increase resistance as able to work quad.


  • Weight shifting
  • Single limb stance
  • Single leg crouch (slight)


  • Cone walking – move to single crutch when ready and then d/c crutches when patient ambulates with N gait.


  • EMS may be needed to facilitate quad if contraction cannot be voluntarily evoked
  • EGS may be needed to help control swelling and increase circulation
  • Ice should be used following exercise and initially every hour for 20 minutes

*Perform HEP 3X/Day



By end of this phase, the patient should ambulate with N gait I, have good quad control, controlled swelling, and be able to ascend/descend stairs.


  • Quad sets are continued until swelling is gone and quad tone is good
  • SLR (4 way) add ankle weights when ready
  • Shuttle/Total gym – bilateral and unilateral- focus on weight distribution more on heel than toes to avoid overload on Patella tendon
  • Multi-hip – increase intensity as able
  • Closed chain terminal knee extension (TKE)
  • Leg Press
  • Step-ups – forward
  • Step-overs
  • Wall slides
  • Mini-squats – focus on even distribution of weight
  • Calf raises
  • Hamstring curls (for all patients)


  • Continue with HS and calf stretching


  • Goal is 0-125°
  • Perform scar massage aggressively at portals
  • Prone hangs (do not add weight to ankle) w/BF
  • Heel slides – seated and/or supine
  • Continue with cycling, increasing duration and intensity


  • Single leg stance – even and uneven surface – focus on knee flexion
  • Plyoball – toss
  • Lateral cone walking with single leg balance between each cone


  • Cone walking – forward and lateral
  • D/C crutches when N gait


  • Continue to use ice following exercise

*Continue with HEP

Pt will usually be measured for more functional brace during this period. Can D/C IROM around week 4, when crutches are no longer needed.


Weeks 4-8
Goals for this phase are full quad control and good quad tone; patient should be able to perform N ADLs without difficulty.

Exercises will be advanced in intensity based on quad tone – a patient who continues to have poor quad tone must not be advanced to activities that require high quad strength such as squats and lunges


  • Continue with above exercises, increasing intensity as able
  • Step-ups – forward and lateral; add dumbbells to increase I; focus on slow and controlled movement during the ascent and descent
  • Squats – usually around week 5 – Smith press or standing
  • Lunges – wk 5-6; forward and reverse; add dumbbells or med ball
  • Hamstring curls (not until wk 7 for HS graft)
  • Swiss ball and foam roll hamstring exercises – supine bridge with knee flexion, bridge with HS curl
  • T-band hip flexion
  • Single leg squats– focus on keeping hips level and avoiding dynamic knee valgus.
  • Russian dead lifts – bilateral and unilateral
  • Single leg wall squats
  • Cycle – increase intensity; single leg cycle maintaining 80 RPM


  • Goal is 0-140°
  • Work to full ROM – continue with heel slides
  • Plyoball – toss – even and uneven surface
  • Squats on balance board/foam roll/airex
  • Strength activities such as step-ups and lunges on airex


  • Continue to use ice after exercise

*Continue with HEP at least 3X/week


Weeks 8-12
Exercises for strengthening should continue with focus on high intensity and low repetitions (6-10) for increased strength.

Hamstring and calf stretches should also continue.

Quad stretch should be implemented.

Initiate lateral movements and sports cord: lunges, forward, backward, or side-step with sports cord, lat step-ups with sports cord, step over hurdles.


Ten weeks is the earliest that jogging will be implemented. Based on quad tone, no swelling, and permission from Dr. Lintner, the patient can begin to jog at a slow to normal pace focusing on achieving normal stride length and frequency. The patient must be able to maintain level pelvis and have no dynamic knee valgus on a single leg squat before starting to jog/run.Initiate jogging for 2 minutes, walking for 1 until this is comfortable for the patient and then progress the time as able. Jogging should first be performed on a treadmill or track (only straight-aways) and then progressed to harder surfaces such as grass and then asphalt or concrete. It is normal for the patient to have increased swelling as well as some soreness but this should not persist beyond one day or the patient did too much.

Jump rope and line jumps can be initiated when the patient is cleared to jog.

This can be done for time or repetitions and should be done bilaterally and eventually, around 12 weeks progressed to unilateral.

Jogging and plyos should be performed with brace on.


Weeks 12-16
Progress with stretching and strengthening program (2-3X/week)
Progress jogging speed and distance

Progress plyos: Sportsmetric or similar jumping program can be implemented

Bilateral and unilateral plyos on shuttle

Plyos can include squat jumps, tuck jumps, box jumps, depth jumps, 180 jumps, cone jumps, broad jumps, scissor hops

Leg circuit: squats, lunges, scissor jumps on step, squat jumps

Power skipping

Bounding in place and for distance

Quick feet on step – forward and side-to-side – use sports cord

Progress lateral movements – shuffles with sports cord; slide board

Ladder drills

Swimming – all styles

Focus should be on quality, NOT quantity

Landing from jumps is critical – knees should flex to 30° and should be aligned over second toe. Controlling valgus will initially be a challenge and unilateral hops should not be performed until this is achieved.


Weeks 16-32
Initiate sprints and cutting drills.
Progression: Straight line, figure 8, circles, 45° turns, 90° cuts
Sports specific drills
Biodex test

Single leg hop test (two consecutive hops on one leg): goal is >80% of uninjured leg


Expect Return to Play at 6 months.

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