EFFECTS OF NEUROMUSCULAR TRAINING ON BIOMECHANICAL EFFICIENCY IN HIGH SCHOOL ATHLETES

摘要

Background: Anterior cruciate ligament (ACL) injuries are among the most common and devastating sports-related knee injuries. Neuromuscular training (NMT) has demonstrated efficacy as a preventive intervention for ACL injury and has been associated with improvements in measures of sports performance, but the specific physiologic mechanisms that serve as protective factors and contribute to improved performance haven not been well-defined. Hypothesis/Purpose: The purpose of this study is to investigate the association between NMT and biomechanical efficiency among high school athletes. We hypothesized that the performance of NMT is associated with improved biomechanical efficiency during the performance of fundamental movements and agility tests when compared to a group of untrained control subjects. Methods: Eight high school soccer and basketball teams (111 athletes, 53.1% male, mean age 15.6 years) were recruited and assigned to either an intervention or control group. The intervention group performed NMT as part of their warm-up prior to each practice and competition for 12 weeks. NMT was administered by experienced sports medicine clinicians who provided exercise instruction, technique cues, and performance feedback throughout each training session. The control group performed their customary warm-up under the direction of the team’s coaches. Biomechanical efficiency was assessed through performance of static and dynamic tests using an FDA-approved wireless sensor system. Agility was assessed using a timed three-cone agility test. All tests were administered immediately prior to and following each competitive sports season. Results: Matched pre-/post-season data was collected from 74 athletes (67%). Significant improvements [point estimate (95% CI) p-value] were observed in the intervention group for left lower extremity [0.25 (0.06,0.45) p = 0.01] and right lower extremity [0.21 (0.05,0.37) p = 0.01] loading/landing speed ratios during a single leg hop test, left lower extremity [-136.34 (-225.74,-46.95) p = 0.003] and right lower extremity [-110 (-211.36,-8.64) p = 0.03] ground reaction force, left lower extremity [-1.03, (-.189,-0.18) p = 0.02] and right lower extremity [-0.94 (-1.73,-0.14) p = 0.02] initial peak acceleration, and cadence [-12.12 (-21.60,-2.65) p = 0.01] during a straight-line running acceleration/deceleration test, and time [0.51 (0.24,0.78) p = 0.0003] during a three-cone agility test. Conclusion: Results demonstrate that season-long, sport-specific, age-appropriate NMT administered by sports medicine clinicians can significantly improve biomechanical efficiency during the performance of fundamental movements and agility tests by high school athletes. To achieve similar results, sports coaches should be trained to provide exercise instruction, technique cues, and performance feedback when administering NMT in real-world settings. Table 1. Participant Demographics Demographics Control (N=40) Intervention (N=71) Sex (%) Male 47.5 56.3 Female 52.5 43.7 Race (%) American Indian 2.5 .90 Asian 0 5.6 Black/African American 62.5 9.9 Middle Eastern 0 4.2 White/Caucasian 0 54.9 Other 27.5 22.5 Unknown 10.0 2.8 Ethnicity (%) Hispanic or Latino 47.5 36.6 Not Hispanic or Latino 52.5 60.6 Unknown 0 2.8 Age in years (Mean) 15.4 15.8 BMI (Mean) 23.4 21.9 Upper Extremity Limb Dominance (%) Left 5.0 14.1 Right 95.0 85.9 Lower Extremity Limb Dominance (%) Left 10.0 16.9 Right 90.0 83.1 Previous ACL Injury (%) 2.5 1.4 Table 2. T-test Results Test Measure N Post-Preseason Control Mean Post-Preseason Intervention Mean Difference Control-Intervention 95% CI P-Value Single Leg Squat Squat speed Translation Average Left 74 -1.88 -4.38 2.5 (-1.47,6.46) 0.21 Squat speed Translation Average Right 74 -5.23 -3.55 -1.68 (-6.06,2.69) 0.45 Medial/Lateral Tibial Translation Average Left 74 0.05 0.22 -0.17 (-0.44,0.08) 0.17 Medial/Lateral Tibial Translation Average Right 74 0.3 0.1 0.2 (-0.14,0.53) 0.25 Double Leg Squat Squat Speed Translation Average Left 73 -3.77 -3.39 -0.38 (-3.44,2.67) 0.8 Squat Speed Translation Average Right 73 -0.39 -4.34 3.95 (0.21,7.87) 0.04 Medial/Lateral Tibial Translation Average Left 73 0.03 0.11 -0.08 (-0.52,0.37) 0.73 Medial/Lateral Tibial Translation Average Right 73 0.03 0.32 -0.29 (-0.80,0.21) 0.25 Single Leg Hop Hop Speed Ratio Average left 74 0.12 -0.13 0.25 (0.06,0.45) 0.01 Hop Speed Ratio Average Right 73 0.11 -0.1 0.21 (0.05,0.37) 0.01 Hop Flight Time Average Left 74 -0.03 -0.01 -0.02 (-0.06,0.02) 0.39 Hop Flight Time Average Right 73 -0.06 -0.02 -0.04 (-0.09,0.01) 0.11 Medial/Lateral Tibial Translation Average Left 74 0.01 0.21 -0.2 (-0.50,0.09) 0.17 Medial/Lateral Tibial Translation Average Right 73 0.05 0.09 -0.04 (-0.53,0.46) 0.87 Acceleration Deceleration Ground Force Reaction Left 74 -98.41 37.93 -136.34 (-225.74,-46.95) 0.003 Ground Force Reaction Right 74 -92.07 17.93 -110 (-211.36,-8.64) 0.03 Initial Peak Acceleration left 74 -1.1 -0.07 -1.03 (-1.89,-0.18) 0.02 Initi