Continuing to train whilst injured can be hugely beneficial to reducing the overall impact of injury on quality of life. This is particularly true when training the uninjured limb in an upper or lower limb injury, where training the unaffected side can hugely mitigate strength loss and promote active rehabilitation. The cross-education effect can be a hugely useful tool in the initial rehabilitation phase to maintain strength in the affected and unaffected limb.
Cross-education refers to the specific training of the unaffected limb to aid in the improvement of strength and function of the injured limb. This is in reference to the contralateral limb to the injured side, and can be applied to a range of injuries including, but not limited to, ACL injury, fractures of the limbs, stroke rehabilitation, joint injuries, and other post-surgical rehabilitations.
It can be applied at various stages of the rehabilitation process, but can be used particularly in the early stage of rehabilitation. The early stages of rehabilitation are primarily where there is the greatest difference in limb strength between injured and uninjured sides, and disability to the affected limb as well. Hence why it is more pertinent at this point in time.
The method in which cross-education works is through mitigating changes in the brain. Commonly in the acute phase of immobilization, changes occur in the brain’s central nervous system that causes a reduction in muscle strength and muscle thickness. Contralateral limb training is thought to activate the neural circuits that are supposedly affected, thereby mitigating the deleterious effects of detraining and immobilization that occurs.
It is worth noting that cross-education is one of many adjuncts that can be used post-injury to attenuate losses in strength, function, muscle size, proprioception and so on. It is simply a part of the solution, not the be all and end all!