Feedback techniques to target functional deficits following anterior cruciate ligament reconstruction: implications for motor control and reduction of second injury risk

Abstract

Primary anterior cruciate ligament (ACL) injury prevention training has been shown to reduce the risk of injury. Less is known about the effect of prevention on second injury after ACL reconstruction (ACLR). Given recent findings that second injury rates exceed 20 % in only the first year following the return to sport, it is imperative that rehabilitation after ACLR is scrutinized so that second injury preventative strategies can be optimized. A potential limitation of current rehabilitative processes following ACLR could be a deficiency in the transition from conscious awareness achieved during rehabilitation sessions to unexpected and automatic movements required for athletic activities on the field. Learning strategies with an internally directed focus have traditionally been utilized but may be less suitable for acquisition of control of complex motor skills required for sport reintegration. Conversely, an externally focused rehabilitation strategy may enhance skill acquisition more efficiently and increase the potential to transfer to competitive sport. This article presents new insights gained from the motor learning domain that may improve neuromuscular training programmes via increased retention from improved techniques and may ultimately reduce the incidence of second ACL injuries.

Fig. 1

Internal focus a versus external focus b instructions during a drop vertical jump. In a, the patient was instructed to land while bending the hips and knees; in b, the patient was instructed to touch the cones when landing. Note the increased hip and knee flexion with the external focus instructions compared with the internal focus instructions

Fig. 2

Real-time feedback during a squat. The patient receives information on the magnitude and direction of ground reaction forces. Visual and auditory cues are provided to correct imbalances

Fig. 3

Video overlay of the model performing a drop vertical jump. Immediate after the drop vertical jump, the patient can view the overlap and try to increase their overlap with the model in the subsequent trial