Knee injury is one of the most common injuries sustained in sports. It can be in the form of meniscal or ligamentous injury, the most notorious being the Anterior Cruciate Ligament (ACL) tear. As a result of such injuries, athletes of ten get frustrated as they are unable to perform as their best or even engage in the sport itself. More often than not, athletes do not manage their injuries well and many will attempt to return to sports much earlier than optimal and usually end up worse than before.
Bringing a competitive athlete from injury back to sports requires much more planning than just restoring range of motion and strength. It requires a good understanding of the healing processes, in depth knowledge of strength and conditioning as well as biomechanics of the body in relation to each sport, and the most important of all, the abiloty to implement the rehabilitation process systematically and appropriatelly. It is a science all to itself.
There are three phases in the rehabilitation process; healing and restoration phase, sports conditioning phase. Healing and restoration phase usually takes about four to six weeks and aims to get the athlete back to full range of motion and normal gait. Strength and conditioning phase takes another six to eight weeks with the aim of helping the athlete regain about 80% strength, and at the same time progressively improve their cardiovascular endurance. Finally, the sports conditioning phase aims to improve agility, balance, power and coordination. The phases are not distinct but overlap. With a thorough rehabilitation process, the athlete would be able to return to his sports with a firm foundation in all the key components of physical fitness, allowing him to ease into his sports training with confidence.
Healing and restoration phase (Week 0-4); Aims:
- Reduce swelling and effusion to minimum
- Restore normal gait pattern
- The management of a knee immediately post-operatively focuses on the reduction of swelling and effusion and restoration of range of movement. Exercise such as isometric knee extension is introduced as well to reduce the rate of muscle control.
Strength and Conditioning phase (Week 4-12); Aims:
- Full range of motion and minimal swelling
- Unilateral knee exercises
- Achieving 80% muscle strength of the non injured knee
Once the swelling has reduced significantly, full extension restored with flexion achieved to about 100-120 degrees, and normal gait almost regained, the athlete is then put through other strengthening exercises which can including cycling, leg press, step downs, mini squats (0-45 degrees flexion). All these exercises should be done with both legs, with emphasis on smoothness of execution of movement. The athletes are loaded with low weights at first and then progressed gradually to higher weights with low repetitions. Cardiovascular endurance exercises are also started at this place.
Unilateral knee exercises can be started once the athlete has sufficient muscle control to do a single knee squat of 0-45 degrees flexion. Once the quadriceps and hamstring muscles of the operated knee can achieve about 80% strength of the uninvolved knee, it is time to move on the next phase. The strength of the uninvolved knee, it is time to move on to the next phase. The strength of the knee can be easily gauged by testing the knee on a leg press machine, comparing the weights that be achieved by each knee on a single set of 15 repetitions. A much more accurate test of the strength of the muscles can be done using the isokinetic machine.
The isokinetic strength test is widely used in sports clinics to evaluate the strength of muscles pre and post operatively. However the main drawbacks of the test are that the data does not accurately determine the different performance between athletes of varying skill levels and do not correlate strongly with functional tasks.
Sports Conditioning Phase (Week 12 onwards); Aims:
- Achieve 90-100% muscle strength in quadriceps and hamstrings
- Achieve 90-100% in functional testing
- Athlete is able to perform sports specific movements with ease
Once the athlete can achieve 80% of quadriceps muscle strength and good control over single leg exercise, the next step will be to do functional tests to gauge the performance of the knee. Functional tests have been devised for athletes who has ACL reconstruction done. The tests include jumps, hops, agility and quickness in navigating turns. Various components of physical fitness listed above are tested i.e agility, balance, power and co-ordination. As such, the tests are also suitable to be applied to chart the progress of athletes recovering from post-operative meniscal repair, menisectomy and other ligamentous injury. Being functional, the tests would also be more meaningful as they mimic the movements that would be performed during the sport itself. At this phase, the athletes will be continuing to increase the basic muscle strength through the similar exercises listed in phase 2. These strengthening exercises will form the foundation from which the athletes will be trained in the other components.
Balance is a state of equilibrium, the ability to control the body’s position at rest or in motion. The athlete starts his balance training through balancing on 1 leg on a flat surface before progressing to balancing on unstable surface such as a wobble board. Subsequently, single leg hopping exercises will be introduced and progressed to multi-directional movements, where the level of difficulty is increased.