Post on 21-Sep-2020
Introduction
Risk factors for non-contact ACL injury
The purpose of this study was to prospectively evaluate risk factors for non-contact ACL injury in female high school basketball players.
Materials and Methods
Results
Conclusion
Greater muscle strength may lead to joint stabilization and reduce ACL injuries1).
Weakness in the hip abductor strength may lead to occur greater hip adduction and internal rotation
which cause increasing knee valgus and knee abduction moments2).
Lower balance ability is a risk factor for ACL injury3).
Prospective 3-year cohort study
195 elite high school
female basketball players
171 players
Non-contact ACL group
14 players
Evaluation items
Height(cm), Body weight(kg), Body mass index(%)
Anterior laxity of the knee; KT-1000 arthrometer®(mm)
General joint laxity(point)
Femoral anteversion(degree)
Navicular drop measurement;Sitting-Standing(mm)
Muscle strength during knee ext. and flex.; MYORET ® dynamometer(Nm/kg)
Muscle strength during hip abd.; Micro total analysis system F-1 ® (Nm/kg)
Locus length(cm/s)
Environmental area(cm2)Greater body mass index and muscle strength of hip abduction were risk factors for
non-contact ACL injury in female Japanese high school basketball players.
On high school enrollment, the athletes were administered a baseline survey
as presented bellow.
24 excluded because they either had history of ACL injury or could not complete the study because they were unwell on the day of baseline survey.
Control group
156 players
ACL injuries were diagnosed at a medical institution following full physical
examination and magnetic resonance imaging, and after direct arthroscopic
visualization confirmed a complete ACL tear during subsequent ACL
reconstruction.
1 player excluded because she injured by contact injury mechanism.
A total of 16 ACL tears occurred.(15 players) 1 player had bilateral ACL injury.
During game 9 knees, During practice 5 knees
Feint 6 knees, landing 4 knees, others 4 knees)
Left 10 knees, Right 4 knees (71% non-dominant leg injury)
Junsuke Nakase, Katsuhiko Kitaoka, Yosuke Shima, Takeshi Oshima, Yasushi Takata, Hiroyuki Tsuchiya
Department of Orthopaedic Surgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
Nothing to disclose
High body mass index and hip abductor muscle were risk factor for non-contact ACL injury in female high school basketball players
-A prospective three-year cohort study-
1) Lloyd DG, et al. Med Sci Sports Exerc. 20052) Claiborne TL, et al. J Appl Biomech. 2006
We hypothesized that female high school basket ball players suffering non-contact ACL injuries would demonstrate weaker hip abductor and knee flexor muscle strength and poor static balance, when compared to those without ACL injury.
Though various worldwide studies have addressed this subject, a clear consensus has yet to be reached.
This study was approved by the ethics committee of our institution, and informed consent
was obtained from the participants and their parents after providing a thorough explanation, in
both written and oral formats, on the content of this research before the investigation.
References
Statistical analysis
The data were analyzed using the Statistical Package for the Social Sciences for Windows, (version 23.0; SPSS Inc., USA).The assessment parameters between the ACL injury group and the control group were first compared using the Student t-test: The parameters of muscle strength were assigned to the injured side in the ACL injury group and randomly left andright in the control group. Then the assessment parameters with a P values less than 0.2 were considered independentvariables by logistic regression analysis (simultaneous). The level of significance for all statistical analysis was set at α= 0.05(values of P< 0.05 were considered statistically significant).
Student t-test
Logistic regression analysis
The main findings of this 3-year prospective cohort study were that, contrary to our hypothesis, greater BMI and hip abductor muscle strength
were risk factors for non-contact ACL injuries.
The ACL injury group tended to greater knee flexor and extensor muscle strength than the control group. High level athletes have greater muscle strength, similarly the weight and BMI increase accordingly. Also, the playing time included games and practices is long. The chances of encountering situations that such as cutting and landing may be increased. In our study, almost all of the non-contact ACL injuries were regular players. It was reported that High level athletes had a long playing time and they were often exposed encountering situations4).
3) Vrbanic TS, et al. Coll Antropol. 20074) Soligard T, et al. Br J Sports Med. 2010.
Strength
Prospective study
High incidence rate
Large sample size
High follow up rate
confirmation of a complete ACL tear
by directly arthroscopic visualization.
Limitation
Baseline survey was done only at the time of enrollment
We were unable to record actual playing time include
practice or game.