1.Biomechanical study of laterality and stability during double-leg landing of college competitive aerobics athletes
Lili WANG ; Wan Ahmad Munsif Bin Wan Pa ; Yuxuan WANG ; Fenglei LI ; Mengning JIE ; Denise Koh Choon Lian
Chinese Journal of Sports Medicine 2024;43(4):266-274
Objective To analyze the biomechanical characteristics of the landing movements of com-petitive aerobics athletes,compare the laterality between their dominant and non-dominant limbs,and to explore the primary factors influencing landing stability.Methods Taking 26 female aerobics athletes in universities as the research objects,their kinematics and kinetics data of double-leg vertical land-ing with the height of 40 cm were simultaneously recorded.A comparison was made between the two limbs in terms of joint angles at initial contact,range of motion(ROM)of joint,ground reaction force(GRF),load-rate,the displacement and envelope area of the center of pressure(COP).The symmetry index(SI),reflecting laterality,was computed,and a multiple stepwise regression analysis was conduct-ed to examine the correlation between parameter asymmetry and COP envelope area.Results Compared with the non-dominant limbs,the dominant limbs had significantly greater knee external rotation and hip abduction angle at initial contact(P<0.05),significantly greater ROM of the ankle and hip flexion-extension and hip adduction-abduction,and smaller ROM of ankle rotation during landing(P<0.05).Moreover,the peak knee extension moment of the dominant limbs was significantly higher than the non-dominant limbs(P<0.01).The SI of vertical load rate and peak knee extension moment were signif-icantly positively correlated with the COP envelope area(P<0.05).In addition,the SI of vertical load rate,peak knee extension moment and knee rotation angle could explain 83.6%of the difference in the COP envelope area.Conclusion There is laterality between the dominant and non-dominant limb of competitive aerobics athletes during landing:the greater laterality of the load rate and peak knee ex-tension moment,the worse the landing stability.Furthermore,the SI of vertical load rate,peak knee extension moment,and knee rotation angle can be used as predictors of the landing stability.