ACL Surgery Recovery

By Robert Donatelli, PhD PT

Following an ACL reconstructive surgery coming back to play naturally depends on pivotal movements—the ability to run, jump and change direction at high rates of speed. In addition to providing stability, the knee and ankle are subjected to excessive forces during pivotal movements, and consequently, are frequently injured. In fact, knee surgery has become a common procedure during the last decade. The most common knee injury is to the ACL, since it is the most vulnerable to the stress of pivotal movements like the cutting maneuvers required in many sports. 

The four primary ligaments that contribute to the knee’s stability are:

• ACL (anterior cruciate ligament)
• PCL (posterior cruciate ligament)
• LCL ( lateral collateral ligament)
• MCL (medial collateral ligament)

A dynamic rehabilitation program after the ACL surgery is critical for the success of the operation.

Surgical success is measured by the patient’s ability to return to the running, jumping and cutting activities of their specific sport. There are many articles on the advantages of Closed Kinetic Chain exercises in the safe rehabilitation of an ACL repair. CKC exercises reduce stress on the ACL and enhance the knee’s dynamic stability by co-contraction of muscles around the joint. Squats or leg press is an example of closed kinetic chain exercises. In addition to CKC exercises there are other exercises designed to facilitate neuromuscular control by reducing the voluntary activation times of the muscle.

The Journal of Orthopedic and Sports Physical Therapy dedicated two issues to current theories on how dynamic knee stability may be achieved through neuromuscular control.  Neuromuscular control is defined as “a complex interaction between the nervous system and the muscle.” There is evidence that the rehabilitation of the neuromuscular system can improve reflex mechanisms to prevent knee ligament injuries during athletic activities.

The sensors that are part of the neuromuscular system are called mechanoreceptors. These mechanoreceptors are located in soft tissue structures such as the knee’s primary ligaments and respond to various forms of tension and compression. These receptors provide information to the central nervous system, which then modifies conditions at the local level, such as the knee, by varying muscle activity. Athletes who sustain a torn ACL may experience a decline in neuromuscular control that can contribute to progressive instability of the knee.

Stability, balance and plyometric exercises produce reductions in voluntary activation times of muscle. This time reduction enables athletes to perform rapid and unexpected sports maneuvers. External loading of the knee and ACL ligament that is performed in various sporting activities produces a peak push-off and weight acceptance that may contribute to an ACL injury.

What should rehab consist of? 

Based on the above rationale, a rehabilitation program should consist of:

1. Increased use of coordinated muscle contractions of the hamstrings and quadriceps muscles.
2. Increases in the performance of the whole body in coordinated multi-joint movement patterns.
3. Exercises to strengthen the knee ligaments and soft tissue structure that are important for stability.
4. Plyometrics to improve in-voluntary activation times and strength, especially the hamstrings.
5. Movement patterns that will rehabilitate the neuromuscular system allowing the athlete to return to their sport with reduced risk of re-injury and improved performance.

Rehabilitation after ACL surgery is not an easy task, so preventative measures are important to avoiding injury in the first place. Research has shown that exercises involving the neuromuscular system can reduce the chances of ACL injury by 60 to 70 percent. If you do need ACL surgery and wish to return to athletic activity, make sure you choose you rehabilitation facility carefully. The recent advances discussed in this article aren’t automatically in all rehab programs.

A dynamic rehabilitation program after the ACL surgery is critical for the success of the procedure. Returning to activity or any competitive sport that involves jumping, running, and cutting is not easy after reconstructive surgery to the ACL. The rehabilitation should be done by a licensed practitioner who is up on the new evidence that can be a critical factor in the athlete’s ability to return to play with the reduced risk of re-injury.

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