{"title":"Bilateral Ground Reaction Force Asymmetry During Supramaximal Drop Landings","authors":"L. Barker, J. Harry","doi":"10.47206/ijsc.v2i1.160","DOIUrl":null,"url":null,"abstract":"Bilateral vertical ground reaction forces (vGRF) asymmetries have not been investigated during supramaximal drop heights. The first purpose of this study was to investigate the influence of drop height on impact and attenuation vGRF impulses. 19 young adults completed the protocol (14 males, 5 females, age: 21.3 ± 0.75 years, mass: 75.1 ± 10.2 kg, height: 171.4 ± 7.9 cm, 1RM back squat relative to mass: 1.72 ± 0.4), which included bilateral drop landings starting at 0.3 m going up to 1.52 m in increments of 0.152 m. Asymmetries were calculated from impact impulse, loading rate, peak vGRF, attenuation impulse, and total impulse. Linear regressions analyzed these variables with respect to drop height at the group and individual levels. All dependent variables measuring asymmetrical force production produced negative regression slopes at the group level, but the adjusted R2 values ranging 0.06 to 0.15 indicate drop height accounted for minimal variance in asymmetry variables. However, examination of individual asymmetry responses reveals noteworthy adjusted R2 values for athlete monitoring and return to play considerations in competitive sport. Seven participants displayed significant reductions in asymmetry values as drop height increased with R2 values ranging from 0.23-0.64. Practitioners and coaches using landing asymmetry measurements to support return to play decisions should consider the inclusion of larger drop heights to avoid false positive asymmetry results and encourage participants to land as quickly as possible with maximal effort.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"14 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Strength and Conditioning","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.47206/ijsc.v2i1.160","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Bilateral vertical ground reaction forces (vGRF) asymmetries have not been investigated during supramaximal drop heights. The first purpose of this study was to investigate the influence of drop height on impact and attenuation vGRF impulses. 19 young adults completed the protocol (14 males, 5 females, age: 21.3 ± 0.75 years, mass: 75.1 ± 10.2 kg, height: 171.4 ± 7.9 cm, 1RM back squat relative to mass: 1.72 ± 0.4), which included bilateral drop landings starting at 0.3 m going up to 1.52 m in increments of 0.152 m. Asymmetries were calculated from impact impulse, loading rate, peak vGRF, attenuation impulse, and total impulse. Linear regressions analyzed these variables with respect to drop height at the group and individual levels. All dependent variables measuring asymmetrical force production produced negative regression slopes at the group level, but the adjusted R2 values ranging 0.06 to 0.15 indicate drop height accounted for minimal variance in asymmetry variables. However, examination of individual asymmetry responses reveals noteworthy adjusted R2 values for athlete monitoring and return to play considerations in competitive sport. Seven participants displayed significant reductions in asymmetry values as drop height increased with R2 values ranging from 0.23-0.64. Practitioners and coaches using landing asymmetry measurements to support return to play decisions should consider the inclusion of larger drop heights to avoid false positive asymmetry results and encourage participants to land as quickly as possible with maximal effort.
双边垂直地面反作用力(vGRF)不对称尚未研究在最大落差高度。本研究的第一个目的是研究落差高度对vGRF脉冲冲击和衰减的影响。19名年轻人完成了实验(男性14名,女性5名,年龄:21.3±0.75岁,体重:75.1±10.2 kg,身高:171.4±7.9 cm, 1RM后蹲相对于体重:1.72±0.4),包括从0.3米开始,以0.152米的增量增加到1.52米。通过冲击冲量、加载速率、峰值vGRF、衰减冲量和总冲量计算不对称性。线性回归分析了这些变量在群体和个体水平上的下降高度。测量不对称力产生的所有因变量在组水平上均产生负回归斜率,但调整后的R2值在0.06至0.15范围内,表明落差高度在不对称变量中占最小方差。然而,对个体不对称反应的检查显示,在竞技体育中,运动员监测和重返赛场考虑因素的调整R2值值得注意。随着落差高度的增加,7名参与者的不对称性值显著降低,R2值在0.23-0.64之间。练习者和教练使用着陆不对称测量来支持回球决策,应该考虑包括更大的落点高度,以避免误报的不对称结果,并鼓励参与者以最大的努力尽快着陆。