Biomechanical measures of neuromuscular control and valgus loading of the knee predict anterior cruciate ligament injury risk in female athletes: a prospective study.
ABSTRACT Female athletes participating in high-risk sports suffer anterior cruciate ligament injury at a 4- to 6-fold greater rate than do male athletes.
Prescreened female athletes with subsequent anterior cruciate ligament injury will demonstrate decreased neuromuscular control and increased valgus joint loading, predicting anterior cruciate ligament injury risk.
Cohort study; Level of evidence, 2.
There were 205 female athletes in the high-risk sports of soccer, basketball, and volleyball prospectively measured for neuromuscular control using 3-dimensional kinematics (joint angles) and joint loads using kinetics (joint moments) during a jump-landing task. Analysis of variance as well as linear and logistic regression were used to isolate predictors of risk in athletes who subsequently ruptured the anterior cruciate ligament.
Nine athletes had a confirmed anterior cruciate ligament rupture; these 9 had significantly different knee posture and loading compared to the 196 who did not have anterior cruciate ligament rupture. Knee abduction angle (P<.05) at landing was 8 degrees greater in anterior cruciate ligament-injured than in uninjured athletes. Anterior cruciate ligament-injured athletes had a 2.5 times greater knee abduction moment (P<.001) and 20% higher ground reaction force (P<.05), whereas stance time was 16% shorter; hence, increased motion, force, and moments occurred more quickly. Knee abduction moment predicted anterior cruciate ligament injury status with 73% specificity and 78% sensitivity; dynamic valgus measures showed a predictive r2 of 0.88.
Knee motion and knee loading during a landing task are predictors of anterior cruciate ligament injury risk in female athletes.
Female athletes with increased dynamic valgus and high abduction loads are at increased risk of anterior cruciate ligament injury. The methods developed may be used to monitor neuromuscular control of the knee joint and may help develop simpler measures of neuromuscular control that can be used to direct female athletes to more effective, targeted interventions.
- SourceAvailable from: Frank Noyes, M.D.[show abstract] [hide abstract]
ABSTRACT: The purpose of this study was to test the effect of a jump-training program on landing mechanics and lower extremity strength in female athletes involved in jumping sports. These parameters were compared before and after training with those of male athletes. The program was designed to decrease landing forces by teaching neuromuscular control of the lower limb during landing and to increase vertical jump height. After training, peak landing forces from a volleyball block jump decreased 22%, and knee adduction and abduction moments (medially and laterally directed torques) decreased approximately 50%. Multiple regression analysis revealed that these moments were significant predictors of peak landing forces. Female athletes demonstrated lower landing forces than male athletes and lower adduction and abduction moments after training. External knee extension moments (hamstring muscle-dominant) of male athletes were threefold higher than those of female athletes. Hamstring-to-quadriceps muscle peak torque ratios increased 26% on the nondominant side and 13% on the dominant side, correcting side-to-side imbalances. Hamstring muscle power increased 44% with training on the dominant side and 21% on the nondominant. Peak torque ratios of male athletes were significantly greater than those of untrained female athletes, but similar to those of trained females. Mean vertical jump height increased approximately 10%. This training may have a significant effect on knee stabilization and prevention of serious knee injury among female athletes.The American Journal of Sports Medicine 01/1996; 24(6):765-73. · 4.44 Impact Factor
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ABSTRACT: To report the results of preparticipation physical examination (PPE) performed on 2,739 high school athletes and present a model for providing PPEs in similar practice settings. We analyzed 2,739 PPEs performed on high school athletes by means of a station examination approach in our Sports Medicine Center during a 3-year period. Personnel from the Departments of Physical Medicine and Rehabilitation, Orthopedics, Family Medicine, and Internal Medicine participated in performance of a comprehensive station-based physical examination of high school athletes. The final reviewing physician assigned one of three dispositions to each athlete: cleared for participation in sports, not cleared, or cleared with follow-up recommended. On the basis of PPE findings, 53 athletes (1.9%) were disqualified from participation in sports. Abnormalities that did not preclude participation but necessitated follow-up were identified in another 327 athletes (11.9%). Musculoskeletal problems were the leading cause of restriction from sports activities (43.4%) and the second leading cause for recommended follow-up (27.8%). Clinically significant cardiac abnormalities were noted in only 10 athletes (0.37% of the overall group of students). Our methods and results are discussed in relationship to previous PPE studies. On the basis of this study, we conclude that (1) a Sports Medicine Clinic can efficiently administer PPEs to a large number of athletes by using an adaptable station approach, (2) the musculoskeletal component of a PPE is an important part of the process that often reveals abnormalities and should be performed by qualified personnel, and (3) each practice must refine its delivery of PPEs on the basis of its particular environment.Mayo Clinic Proceedings 06/1998; 73(5):419-29. · 5.79 Impact Factor
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ABSTRACT: Proprioception and neuromuscular control of the knee are compromised after ligament injury and must be regained if the athlete is to return to high level sports at a normal injury risk level. The anterior cruciate ligament deficient and reconstructed knee will be used as a model to describe differences in proprioception and neuromuscular control to those of an uninjured knee. The purpose of the current review is threefold. First, the basic science of proprioception and neuromuscular control specific to the knee will be summarized and reviewed. The review will include an overview of terminology, neurophysiology, and the effects of injury on the function of both lower limbs. Second, tools used for assessment and rehabilitation of proprioceptive deficits will be evaluated. Specific rehabilitation procedures that incorporate prophylactic conditioning that focus on transitioning the injured athlete back into sport will be presented. Finally, the literature with respect to gender variation in proprioception and neuromuscular control will be evaluated. The goal of the current review is to provide the clinician and the clinical scientist with sufficient background information for the development of quantitative methods to evaluate a patient's functional capacity and to assist in preventative, preoperative, and postoperative decision-making strategies.Clinical Orthopaedics and Related Research 10/2002; · 2.79 Impact Factor