Anterior Cruciate Ligament (ACL) Injury Conservative Management

There are three phases to rehabilitating your knee after ACL injury. 

Phases in ACL knee rehabilitation (dependent on other knee injuries sustained at time e.g. bone bruising, medial ligament sprain etc )

Phase 1

Approx up to 3 weeks 

Phase 2

Approx 4-6 weeks 

Phase 3

Approx 7-13 weeks 

Phase 4 

Approx 13 weeks to 9 months 

Phase 5

Approx +9 months 

Average time frames for return to normal activities of daily living 

Driving 

Up to 4 to 6 weeks depending on advice with your insurance company. Or as soon as full pain free knee motion with no locking 

Return to Work 

• Sedentary/Desk based activities usually within 4 to 6 weeks. May be earlier if working from home.
• Heavy duty work e.g. construction, usually 3 months. 

Sports 

• Cycling/swimming usually after 8 weeks.
• Jogging/running usually after 3 months post injury.
• Golf usually after 3 to 4 months post injury.
• Jumping/hopping/cutting activities/changing direction usually after 12 weeks. 

These timescales are only a guide and may vary between individuals. Always seek advice from your physiotherapist/consultant. 

Phase 1 – Immediately post injury 

Approx up to 3 weeks 

Aims 

• Protect the knee 

• Reduce pain and swelling. 

• To be able to manage and mobilise with crutches. 

• Begin movement exercises, bending and straightening the knee. 

• Begin muscle strengthening exercises. 

Advice 

Put your leg up regularly throughout the day. Use ice packs for 10 minutes every couple of hours to help reduce the pain, swelling and bruising, if present.  

Application of ice can be repeated regularly, every 2 hours (while awake) in the first 24 hours. It must be done carefully. It is possible to get an ice burn. 

Technique for the application of ice treatment at home 

1. Use either a bag of frozen peas or a plastic bag with ice cubes.
2. Cover the area to be treated with a damp tea towel or damp cloth.
3. Place the ice pack over the area and hold in position with a towel or bandage.
4. Leave for 10 to 15 minutes on bony areas. 20 to 25 minutes over more fleshy or muscular areas.
5. Check the skin every 5 minutes and if painful or damaging the skin, remove the ice pack. 

Guidance for Return to normal activities of daily living 

The aim of phase 1 is to get the best start to the rehabilitation process. Many of your normal day to day activities will gradually increase as the pain and swelling settles down and you continue to recover. Your physiotherapist will be able to answer any questions you may have about your progress. 

Walking 

• With crutches for the first couple of weeks. Gradually try to use your crutches less as you increase in confidence and the leg feels strong enough to take your weight.
• You may still feel more confident using the crutches outdoors initially and over slightly longer distances. 
• If you feel your knee is swelling, or there is greater pain these can be signs that you have overdone it. You need to rest more in this case.

Things to Avoid 

• Do not sit and straighten the knee against resistance.
• Do not cross your legs.
• Do not run or jump.
• Avoid twisting and swivelling movements. 

Phase 1 - Exercises

*N.B. Achieving full range of motion in the first few weeks after the injury is crucial.  This speeds progress and return to sports.  There is evidence that it could prevent arthritis in the knee later in life.

Phase 2 – Increasing Activity 

Approx 4 to 6 weeks 

Criteria for Progression onto Phase 2: 

• Minimal or no pain 

• Minimal or no swelling 

• Good range of movement. 

Aims 

• Reduce pain and swelling 

• Restore full range of motion 

• Mobilise independently  

Guidance for return to normal activities of daily living  

• Sedentary/desk based activities usually within 4 to 6 weeks, earlier if working from home. 

• Heavy duty work e.g. construction not usually until 6 to 8 weeks. 

• Driving can be commenced at 4 to 6 weeks under consultation with your insurance company. 

Things to Avoid 

• Do not cross your legs 

• Do not run or jump 

• Avoid Twisting and swiveling movements

Phase 2 – Exercises

1) Continue with the following exercises from Phase 1:  

a. Bending and Straightening (Range of motion) 

b. Kneecap mobilisation

c. Prone hamstring strengthening 

d. Bridging 

e. Calf Raises 

f. Calf, Hamstring and Thigh (Quadriceps) stretching 

Phase 3 – Increasing Strength 

Approx 7 to 13 weeks 

Criteria for progression to Phase 3: 

Must be able to: 

• Fully straighten (extend) the injured knee. 

Preferably be able to: 

• Fully bend (flex) the injured knee. 

• Have minimal pain/swelling 

Aims of the phase 

• To regain full range of movement, if not already achieved. 

• To build up leg strength. 

• To improve balance and coordination. 

Guidance for return to normal activities of daily living  

• Return to moderate manual work as agreed with consultant. 

• Cycling/Swimming usually after 6 to 8 weeks post injury. 

• • Return to swimming (avoid breaststroke leg kick). 

Phase 3 – Exercises  

1. Continue with the following exercises from Phase 1 and Phase 2:  

a. Bending and Straightening (Range of motion) 

b. Calf, Hamstring and Thigh (Quadriceps) stretching 

c. Hip strengthening bridging 

d. Calf Raises 

e. Single leg balance

10) Cardiovascular Fitness 

If you have access to a gym then using a treadmill, stationary bike, rowing machine, cross trainer and step machine are all appropriate. Avoid any equipment that involves a twisting motion of the knees. 

This program is a rough guide on how you can gradually build up your cardiovascular fitness without using gym equipment. You can speed up or slow down your progress through the program as you feel appropriate. 

a) Walking

5 times weekly for 20 to 30 minutes 

Try to find places to walk. These should be over even ground, but with hills to vary the challenge to the legs. 

Exercise progression: add a backpack with weights/books in to your back. 

b) Steps

Climb and descend a set of 10 to 15 steps (stairs). 

Repetitions: 10 to 20 times. 

Sets: 3 sets at a time. 

Weekly: 3 times a week. 

Exercise progression: add a backpack with weights/books in to your back. 

c) Light Jogging

Can be commenced from week 10 to 12 provided no pain or swelling following previous exercises and no limp when walking fast.  

In a Swimming Pool

d) Swimming

Duration: 10 to 30 minutes. 

Weekly: 2 to 3 times a week. 

Front or back crawl only – Breaststroke only if no pain or joint reaction. 

Exercise progression: use a float to increase leg workout. 

e) Aqua Jogging

Use either an ‘aqua jogger belt’ or other floatation device in the deep end of the pool. Your feet should not hit the bottom. Mimic the jogging motion with your legs (and arms, if not needed for floatation). 

Duration: 10 to 20 minutes. 

Weekly: 2 to 3 times a week. 

Phase 4 Rehabilitation: Weeks 13 to 9 months 

Criteria to progress onto phase 4: 

• Full knee range of motion and no pain and swelling. 
• Walking without any aids and able to stand on one leg without difficulty. 
• No feelings of knee giving way. 

Aims 

• Continue to build up strength with emphasis on functional retraining. 
• Progress aerobic fitness to a level appropriate to your normal function. 

Guidance for return to normal activities of daily living  

• If you perform a heavy manual job, consider returning to this post after 12 weeks, if agreed with your Consultant or Physiotherapist. 
• You can return to light sporting activities e.g. light aerobics during this phase. You must, however, have good range of motion, good strength and have minimal swelling or pain to do this. 
• Jogging/running is usually after 3 months post injury. 
• Golf is usually after 4 months post injury. 
• Jumping/hopping/cutting activities/changing direction is usually after 6 months post injury. 
• Contact/Competitive sports e.g. skiing/football/rugby is usually after 9 to 12 months post injury (See Phase 5) 

You should get confirmation from your Consultant or Physiotherapist before returning to such activities. 

Cautions 

No pivoting or twisting activities during the first 6 months post injury. No contact sports during this time period.

Phase 4 – Exercises 

1. Stretches 

Continue stretching exercises for the calf, hamstrings and thigh (quadriceps) as in the previous Phases outlined. 

See diagrams in Phases 1, 2 & 3 

2. Strengthening  

Continue the strengthening exercises already described in the previous Phases: See diagrams in phases 1, 2 & 3 

a) Deep Squats: See previous Phases 3

b) Single Leg Squat: See previous Phases 3

c) Step up: See previous Phases 3

d) Step down: See previous Phases 3

8. General Cardiovascular exercise program

You can speed up or slow down your progress through the program as you feel appropriate. If running is not something you need to return to then you do not need to carry out this part of Phase 4. 

Your Physiotherapist or Consultant will establish if you have adequate strength and knee control to start jogging. You can then start to slowly build up a jogging program, if your lifestyle requires it. The table below demonstrates how you can gradually build up to 30 minutes of continuous jogging. (Table 3)

If you are able to perform 30 minutes of running without pain, you can try the following speed drills. Once again, if your lifestyle doesn’t require sprinting then you do not need to perform these drills. 

• Sprint 20 metres, rest for a minute then repeat 5 times, (slow acceleration and slow stop).
• Sprint 20 metres, rest for a minute then repeat 5 times, (slow acceleration and fast stop).
• Sprint 20 metres, rest for a minute then repeat 5 times, (fast acceleration and fast stop). 

Phase 5 - Return to Sport – from 9 months onwards 

Criteria for the phase: 

• No swelling 
• Good exercise technique 
• Good bilateral leg strength (your Physiotherapist will carry-out tests to help determine this before you start) 

Aims of the phase 

Many patients with an ACL injury will be able to return to sports, especially those sports that do not involved twisting, turning and changing direction. Practicing jumping, hopping and turning exercises before returning can help. However, these exercises have risks and benefits. You may need more specific exercises to help you return to your sport safely. Only you can decide if you want to get back to your sport. The more demanding your sport, the more specific training you will need to do. Building up the level of exercise will help you return to your sport.  

Some patients on attempting to return to their sport feel the knee still feels unstable or ‘gives way’. In patients under the age of 40 years, with no evidence of knee osteoarthritis, ACL reconstruction may be an option. This should be discussed with your Consultant Orthopaedic Surgeon. 

If your knee recovery is progressing well and your sport or hobby demands more dynamic activities then progress to plyometric work may be appropriate. Plyometrics are exercises in which the muscles are repeatedly and rapidly stretched ("loaded") and then contracted (e.g. as in jumping high off the ground or skipping). The aim of plyometrics is to improve muscle power, speed and agility. Please discuss the use of plyometric training with your Physiotherapist before commencing on a programme as not all individuals will require them. 

When Can You Return to Sport? 

The decision to return to sport can be difficult. Many people lack confidence in their knee at first. This takes time to come back. The physiotherapist can test the knee in the department to determine if you are ready. These tests may involve a slight increased injury risk, but are small. We do need to warn you about these. 

The risks can be reduced by: 

• Warming up properly. 
• Strengthening the leg muscles. 
• Improving your balance. 
• Gradually doing jumping, hopping or turning exercises.
• Training for your sport before returning to competition. 

Exercises in the hospital gym cannot replace sports training. You will still need to train for your sport. A coach who knows your sport can help. 

Physiotherapy exercises can reduce the risk of injury. All exercise however has a degree of risk. Your physiotherapist can discuss this with you. 

Guidance for return to normal activities of daily living  

• Jumping/hopping/cutting activities/changing direction usually after 6 months post injury. 
• Contact/Competitive sports e.g. skiing/football/rugby is usually after 9 to 12 months post injury. 

Plyometric Training 

a) Programme Information

Length of time: approximately 12 weeks before progressing onto contact/competitive sport 

Frequency: 48 to 72 hours (2 to 3 days) should be left between plyometric sessions, so between 2 and 4 sessions per week. 

Recovery: During exercises you should wait about 5 and 10 seconds between each jump, and 2 to 3 minutes between sets of jumps. This applies to all plyometric exercises. It's important to balance volume with intensity of exercises to avoid overtraining and injury, particularly because plyometric exercises put a higher level of stress on the muscles and joints. 

b) Volume

Plyometric training volume refers to the total amount of work performed during a plyometric training session or over a period of time, typically measured in terms of the number of repetitions, sets, or ground contacts (GC)* (e.g., jumps or bounds).  

Beginner - no experience 80 repetitions/GC. 

Intermediate - some experience 100 repetitions/GC. 

Advanced - considerable experience 120 repetitions/GC. 

*Ground contact (GC): Each time the foot (or feet) makes contact with the ground during a plyometric exercise, it is counted as one ground contact 

c) Criteria for Plyometrics

Safety: you should be able to squat at least 1RM (section d).  

Speed: you should be able to perform 5 repetitions of a squat, with 60% of your body weight in under 5 seconds.

d) 1RM

A 1RM, or one-repetition maximum, is the maximum amount of weight that a person can lift for one repetition of a given exercise. It is commonly used in strength training and conditioning to assess an individual's maximum strength for a specific lift, such as a squat, bench press, or deadlift. 

The 1RM is a critical measure for several reasons: 

• Strength: It provides a baseline for tracking progress and setting strength goals. 
• Program Design: Helps to personalised a training program. Many training protocols use a percentage of the 1RM to determine the appropriate load for different training phases (e.g., hypertrophy, endurance, strength, plyometrics). 
• Safety and Efficiency: Ensures that the weight used in training is both safe and effective for the individual. 

Estimating 1RM 

• Warm up with lighter weights. 
• Gradually increase the weight while performing single repetitions until you reach the maximum weight you can lift once with proper form. 

Strength Ratio before starting plyometrics 

• The operated side should be at least 90% strength of the non-operated side 
• Overall strength should be x1.5-2 x your body weight 

Plyometric warm up drills 

1) Marching 

Mimics running movements: emphasises posture and movement technique; enhances correct lower body movements for running. 

2) Jogging 

Prepares for high impact and high intensity plyometric drills; include jogging on the toes only – emphasises quick reaction. 

3) Skipping 

Exaggerated form of upper and lower limb movements with the emphasis on quick take off and landing. 

4) Footwork 

Drills that target change of direction, like shuttles, figure 8 movements and striding drills. 

5) Walking lunge drills 

Lunging along the length of your hall or in a straight line outside, alternating between left and right side lunges. 

Lower Body Plyometric Drills 

Equipment: you may benefit from access to an agility ladder and/or plyometric box for some of these exercises. 

1) Jumps in place 

Jumps in place emphasise the vertical component of jumping and are performed repeatedly without rest between jumps. 

2) Standing jumps 

These emphasise either horizontal or vertical components. These are maximal efforts with recovery between jumps. 

3) Multiple hops/jumps 

Involve repeated movement and may be viewed as a combination of jumps in place and standing jumps. An example of this is a zigzag hop. 

4) Bounds 

Bounding drills involve exaggerated movements with greater horizontal speed than other drills. Volume for bounds is usually measured by distance but can be measured in the number of hops performed. 

5) Box drills 

These drills increase the intensity of multiple hops or jumps by using a box. The box may be jumped on or off. The height of the box depends on the person jumping. 

6) Depth drills  

The athlete jumps from one box and immediately upon landing, jumps onto another box. 

For long term benefits you need to continue to maintain the mobility, strength, balance, coordination and general fitness at your knee. 

Worries or concerns 

For non-urgent issues or concerns 

For non-urgent issues or concerns please contact your Physiotherapist or Consultant’s Secretary through the NHS Fife Hospital Switchboard 01592 643355. 

For urgent issues or concerns 

If you have any urgent concerns regarding your condition, please contact the Physiotherapy Service on 01592 647199. 

Urgent advice for patients between 8am to 8pm Monday to Sunday, contact the National Treatment Centre - Fife Orthopaedics on 01592 643355 Extension 22685. 

Urgent out of the hours advice 

For an urgent problem out of hours, please contact NHS 24 on 111 or attend Accident and Emergency. 

Emergency advice 

For emergency advice, attend Accident and Emergency or call 999.