Effects Of Plyometric Vs Dynamic Balance Neuromuscular Training On Strength And Force Dissipation

Abstract

PURPOSE Neuromuscular training interventions reduce ACL injury rates in female athletes. However, the difficulty and time commitment in teaching and training interventions that use multiple component protocols may preclude coaches, parents and athletes from undertaking training or may decrease compliance once the training is instituted. Hence, efforts should be made to increase the feasibility and efficiency of injury prevention training. The purpose of this study was to evaluate the effects of selectively excluding training components from a protocol shown to reduce measures related to ACL injury and increase measures of performance. Specifically, the hypothesis was that protocols which utilized maximum effort plyometric jumps (PLYO) or dynamic balance exercise (BAL) separately would not have significantly different effects on neuromuscular performance. METHODS Nineteen high school female athletes participated in training 3 X/week for 7 weeks. The PLYO group did not receive any dynamic balance exercises and the BAL did not receive any maximum effort jumps during training. RESULTS BAL training significantly decreased percent change in impact force (p>0.05), while PLYO did not. PLYO training significantly increased isokinetic quadriceps peak (train × side interaction p>0.05), while BAL did not. Both the PLYO and BAL groups decreased their standard deviation of center of pressure (COP) in the medial/lateral direction on their dominant side (side × training interaction; p<0.05), which equalized pre-tested side to side (DOM to Non DOM) differences. Training did not affect COP in the anterior/posterior plane. Both groups increased isokinetic hamstrings peak torque (p>0.01), and hamstrings to quadriceps ratio (p> 0.01). Both training protocols also significantly improved vertical jump (p<0.001), and predicted 1RM measures of bench press (p <0.001), hang clean (p <0.001), and parallel squat (p <0.001). CONCLUSIONS The results of this study demonstrate that both PLYO and BAL training are effective at increasing measures of neuromuscular power and control. However, the PLYO training had significant effects on strength, while BAL had significant effects on decreasing landing force. Though a focus on the efficiency of neuromuscular training protocols for ACL injury prevention is important, both BAL and PLYO may be required for optimal effects. However, if force dissipation is the primary goal, BAL should be emphasized, and if strength is the primary goal, then PLYO could prove more effective. Further investigation into the selective integration of these components may be warranted to maximize training efficiency and effectiveness.