Effects of Knee Joint Muscle Fatigue and Overweight on the Angular Displacement and Moment of the Lower Limb Joints during Landing

Objective : The purpose of this study was to investigate the biomechanical properties of shock absorption strategy and postural stability during the drop landing for each types.Methods : The motions were captured with Vicon Motion Capture System, with the fourteen infra-red cameras (100Hz) and synchronized with GRF(ground reaction force) data(1000Hz). Ten male soccer players performed a drop landing with single-leg and bi-legs on the 30cm height box.Dependent variables were the CoM trajectory and the Joint Moment. Statistical computations were performed using the paired t-test and ANOVA with Turkey HSD as post-hoc.Results : The dominant leg was confirmed to show a significant difference between the left leg and right leg as the inverted pendulum model during Drop Landing(Phase 1 & Phase 2). One-leg drop landing type had the higher CoM displacement, the peak of joint moment with the shock absorption than Bi-leg landing type. As a lower extremity joint kinetics analysis, the knee joint showed a function of shock absorption in the anterior-posterior, and the hip joint showed a function of the stability and shock absorption in the medial-lateral directions.Conclusion : These findings indicate that the instant equilibrium of posture balance(phase 1) was assessed by the passive phase as Class 1 leverage on the effect of the stability of shock absorption(phase 2) assessed by the active phase on the effect of Class 2 leverage.Application : This study shows that the cause of musculo-skeletal injuries estimated to be focused on the passive phase of landing and this findings could help the prevention of lower damage from loads involving landing related to the game of sports.

Section: 번한 발생되는 동작이다 이 때 인체는 다양한 착지 조건에서 발생되는 충격흡수로서 지면반발력을 최소화하고 안unclassified

“…(Winter, et al, 1998;Winter, 2005;Yoo, Kim, & Park, 2012) Cruz et al, 2013;Schmitz, et al, 2007). (Kim & Youm, 2013;Schmitz, et al, 2007). …”

Section: 번한 발생되는 동작이다 이 때 인체는 다양한 착지 조건에서 발생되는 충격흡수로서 지면반발력을 최소화하고 안unclassified

The Biomechanical Properties of the Shock Absorption Phase during Drop Landing According to Landing Types

Park¹,

Yoo²

2015

“…이러한 피로의 누적은 무릎의 동적 안정성에 영향을 미치게 되고, 그 결과, 무릎관절은 느슨 해지고, 운동 제어 능력은 감소되며, 균형 제어 능력과 고 유수용성 감각의 감소가 나타난다 (Johnston, Howard, Cawley, & Losse, 1998;Miura et al, 2004;Rozzi, Lephart, & Fu, 1999). 이 연구에서 나타난 결과와 같이 무릎관절의 누적된 피로로 인한 착지 시 충격 흡수는 발 목관절에 의존하게 되며, 이러한 발목관절의 과도한 부하 는 결국 착지 시 충격력에 의한 부하의 전이를 효율적으 로 제어하지 못하는 원인이 되어 경골의 피로골절, 무릎의 연골 연화증, 연골과 요추 부상 (Dufek & Bates, 1990), 발목 염좌와 비접촉성 전방십자인대 파열 (Chappell, Yu, Kirkendall, & Garrett, 2002;Chappell, Herman, et al, 2005;Decker et al, 2003;Devita & Skelly, 1992;Malinzak et al, 2001) 등의 상해로 이어질 것이다 (Kim & Youm, 2013 (Goulding et al, 2000;McMillan et al, 2010;Smith et al, 2010 …”

Section: 자료 처리unclassified

Effects of Knee Joint Muscle Fatigue and Overweight on Shock Absorption during Single-Leg Landing of Adult Women

Kim¹,

Youm

2014

Self Cite

The purpose of this study was to investigate the effects of knee joint muscle fatigue and overweight on shock absorption during single-leg landing of adult women. Written informed consent forms, which were approved by the human subject research and review committee at Dong-A University, were provided to all subjects. The subjects who participated in this study were divided into 2 groups: a normal weight group and an overweight group, consisting of 15 young women each. Both the normal weight group and the overweight group showed that use soft landing and ankle dominant strategy. The peak vertical ground reaction force, the knee joint absorption power, and eccentric work done, as the increase of knee joint muscle fatigue level, showed a decrease. And the hip joint absorption power and eccentric work done, as the increase of weight, was less than the overweight group showed the normal weight group. In conclusion, the accumulation of the knee joint muscle fatigue and the increase of body weight may lead to an increased risk of injury during landing.

“…로 운동 시 잘못된 점프와 착지 동작은 많은 부상을 유발시키 고 Ford, Myer, & Hewett, 2003), 착지 높이 (Kim, 2011;Barrier et al, 1997;Kovacs et al, 1999), 피로도 (Kim & Youm, 2013;McNitt-Gray, Hart, & Goldin, 1996), 성 별 (Kim, Kim, & Kim, 2010), 질환 , 하지의 동측 및 이측 불균형 (Kim, Kim, & Lee, 2008;Kim, Lee, & Hong, 2011) (Cho, 2004;Self & Paine, 2001).…”

unclassified

Analysis on Differences in Dynamic Stability of Lower Extremity Caused by Unbalance of Hamstring/Quadriceps Ratio During Drop-landing

Hong¹,

min²

2015

Objectives : The purpose of this study was to present quantitative data and basic references to decrease the accident risk of soccer instructors.Methods : To obtain data, we conducted an investigation on how H/Q ratio affects the dynamic stability of the lower extremity at the time of drop landing. The study targeted 13 soccer players from C University who have not had any injuries or wounds in the lower extremity joints and in any other parts of their bodies over the last 6 months. By using CMIS (USA), the players were divided into two groups according to H/Q ratios higher and lower than 69%, respectively. The subjects in each group were instructed to perform a drop landing.Results : The H/Q ratio did not affect the maximal flexion angle of the knee joints at the time of drop landing. In addition the dominant group with a relatively high H/Q ratio was observed to have increased time to reduce shock and to efficiently absorb the ground reaction force during drop landing. Also, the dominant group with a relatively high H/Q ratio utilized the strong performances of the antagonistic muscles around the hamstrings and the controlled rotatory powers of the thighs that were applied to the tibias supported by the ground. Finally, H/Q ratio, load factors, and mean and maximum EMG were significantly negatively related, whereas GRFx showed a positive relationship. In fact, these factors all affected the impact of the load from the H/Q ratio to the knee joints. Conclusion: From these findings it can be concluded that unbalanced H/Q ratio can be considered as a predictor of knee joint injury at the time of drop landing.