여자축구선수의 크로스커팅 동작에서 사전방향 예측여부가 슬관절 부상에 미치는 운동역학적 요인분석

Abstract

Background : In the various sports game situation, performances are not always anticipated but almost occurred by sudden response mechanism. Particularly in soccer game, variations in biomechanical parameters may be occurred with more frequency in unanticipated cross-cutting actions than those of other cases and moreover, it may induce more severe variation in some variables. Therefore the purpose of this study was to examine the kinematic and kinetic effects of between AC and UC direction on the knee injury during cross-cutting motion of female collegiate soccer players.

Methods : Elite female collegiate soccer players(n=13) with righted-leg dominant to verify the study purpose participated in this study. Analysis method of Cinematography(3D), ground reaction force and electromyography(EMG) on the right leg was conducted for the stance phase of the cross-cutting. The UC cross-cutting motion consisted of both an approach run followed by a jump of 0.6 to 0.9 meter before operation of GRF System and a plant-and-cross-cut motion with 45º angle at contact of the right foot on the force platform. Analysed variables were consisted of contact time, ground reaction force, maximal knee angle, maximal ankle angle, maximal knee moment, maximal ankle moment, and signals of EMG around the knee joint respectively. Results : Elapsed support times of AC and UC group were 0.27sec and 0.31sec respectively, of which difference was statistically significant (p=.000). Elapsed times to peak Fx of ground reaction force for the AC and UC group were 0.92sec and 0.78sec respectively, of which difference was statistically significant (p=.039). The ground reaction force pattern of the peak value Fz(second peak) of the AC and UC group were 27.28BW and 24.70BW respectively, of which difference was statistically significant (p=.001). However there was no significant difference between groups in the peak value Fz(first peak). In the initial contact, GRF(peak value Fz) in hip joint angle of UC group showed rather tendency to flex their hip joint(p = 0.00). In the maximum flexion, UC group showed tendency to flex their hip joint (p = .000) and AC group showed tendency to rotate internally(p=.012). In the GRF(peak value Fz) of knee joint angle, UC group showed tendency to do more varus(p = .027) In the maximum flexion, UC group showed tendency to do more flex their knee joint(p = .004), and UC group showed tendency to do more varus in the maximum varus(p=.001). In the maximum dorsiflexion angle, UC group showed tendency to do more dorsiflexion(p = .041) in ankle joint. In the GRF(peak value Fz) in hip joint moment, UC group showed tendency to flex their hip joint more(p = .010). In the maximum flexion, UC group tended to flex their hip joint more (p = .002). There were no significant differences between two groups in knee moment. In the initial contact of ankle joint moment, AC group showed tendency to rotate internally more(p = .050). In EMG analysis of the right lower leg muscles, there were significant differences in only 4 kinds of muscle group.

Conclusion : Kinematic and kinetic variations were more occurred in the mediolateral plane, and variations in muscle activation patterns were more occurred in the lateral gastrocnemius, vastus medialis and lateralis muscles than others. When considering the above, these findings showed the importance of simultaneous strengthening and balance training between muscles of the medial and lateral side of the joint and considered to be helpful materials in program development for an injury prevention in soccer player.