Modifying anterior cruciate ligament injury risk factors in female athletes through real-time biofeedback

With a growing number of females participating in sport activities, the prevention of anterior cruciate ligament (ACL) injuries in female has become increasingly important. Overall, female athletes are more likely to injure the ACL than their male counterparts. Unfortunately, the majority of current preventative training programs face implementation challenges that reduce their widespread adoption as an ACL injury prevention program. The approach used in this study is an effort to overcome prior limitations using a real-time visual feedback training program to reduce biomechanical risk factors associated with ACL injuries. PURPOSE: To develop and test effects of within activity response to real-time biofeedback method that targets and improves movement biomechanics associated with ACL injury risk in females. METHODS: Twenty female collegiate athletes [19.7 yrs. (SD = 1.34), 1.74 m (0.09), and 72.16 kg (12.45)] participated. The study utilized a two-treatment crossover design. Participants were placed into either a real- or sham-first feedback group. The feedback focused on the technical performance of the unweighted back squat. After half the trials, participants were crossed over to receive the alternative treatment. Each participant completed 110 squats—40 training squats for each feedback display and 10 squats during each test period. Participants’ ability to control the feedback was evaluated by a heat map analysis which consisted of calculating a score that indicated the percentage of time the movement caused the stimulus to occupy a correct value. Heat maps were created for pre- and post-tests and each training set of squats. RESULTS: During training sets there was a significant difference in the heat map scores between the real and sham feedback sets, t(19) = 2.94, p < .01. The heat map score during the real feedback sets [M = 60.73%, (6.47%)] was significantly greater than the score during the sham sets [M = 56.62%, (8.42%)], indicating that the real-time biofeedback promoted the desired response during exercise performance. CONCLUSIONS: The heat map scores of participants were higher during the real feedback training sets than the sham feedback training sets indicating real-time biofeedback as a potential training method for modification of risk factors linked to non-contact ACL injury prevention.