Tuff Taylor, Beach Tyson A C, Howarth Samuel J
Department of Research and Innovation, Canadian Memorial Chiropractic College, Toronto, ON, Canada.
Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada.
Int J Sports Phys Ther. 2020 Feb;15(1):53-63.
The side-bridge (SB) is a commonly used closed-chain task to assess trunk muscle endurance and side-to-side endurance asymmetry. An open-chain variation of the SB, that positions the participant in an inclined side-lying posture, may be useful for those who report shoulder pain or fatigue as the reason for terminating the closed-chain SB. Low back loading demands of the open- and closed-chain variations should be matched to facilitate comparison of SB endurance measures.
To quantify the low back reaction moments during the open- and closed-chain SB and determine the appropriate open-chain angle of inclination that matches the lateral bend moment magnitude of the closed-chain SB.
Observational cohort.
Upper body and trunk postural data were obtained during the closed-chain SB and during the open-chain SB at each of four inclination angles from a group of eight healthy male adults. Ground reaction force (GRF) data were also collected during the closed-chain SB. Low back reaction moments were calculated using a static 'top-down' linked segment model in both SB variations. Latent growth modeling was used to determine the angle of inclination in the open-chain SB that produced a low back lateral bend moment that matched the closed-chain SB. Sensitivity of the matching open-chain inclination angle was evaluated by rotating the measured GRF vector from the closed-chain SB by five degrees clockwise and counter-clockwise in the frontal plane.
The open-chain inclination angle that best matched the loading demands of the closed-chain SB was 38 ± 12 degrees. Clockwise rotation of the measured GRF in the closed-chain SB increased the matching inclination angle to 56 ± 17 degrees. Counter-clockwise rotation reduced the matching inclination angle to 17 ± 11 degrees. Secondary descriptive analysis of spine posture and off-axis low back moments revealed biomechanically relevant differences between SB positions.
The average open-chain SB angle of inclination that matched the closed-chain SB approximated the 45-degree recommendation offered in the literature. Differences in spine posture and off-axis low back reaction moments, and the potential impact on holding times, should be considered if using the open-chain SB.
2b.
侧桥（SB）是一种常用的闭链任务，用于评估躯干肌肉耐力和左右耐力不对称性。SB的一种开链变体，将参与者置于倾斜的侧卧位，对于那些因肩部疼痛或疲劳而终止闭链SB的人可能有用。开链和闭链变体的腰椎负荷需求应相匹配，以利于比较SB耐力测量值。
量化开链和闭链SB期间的腰椎反应力矩，并确定与闭链SB的侧弯力矩大小相匹配的合适开链倾斜角度。
观察性队列研究。
从一组八名健康男性成年人中获取在闭链SB和四个倾斜角度下的开链SB期间的上身和躯干姿势数据。在闭链SB期间也收集地面反作用力（GRF）数据。在两种SB变体中使用静态“自上而下”链接节段模型计算腰椎反应力矩。使用潜在生长模型确定开链SB中产生与闭链SB相匹配的腰椎侧弯力矩的倾斜角度。通过在额面中将闭链SB测量的GRF向量顺时针和逆时针旋转5度来评估匹配的开链倾斜角度的敏感性。
与闭链SB的负荷需求最匹配的开链倾斜角度为38±12度。闭链SB中测量的GRF顺时针旋转将匹配的倾斜角度增加到56±17度。逆时针旋转将匹配的倾斜角度减小到17±11度。对脊柱姿势和离轴腰椎力矩的二次描述性分析揭示了SB位置之间的生物力学相关差异。
与闭链SB相匹配的开链SB平均倾斜角度接近文献中提出的45度建议。如果使用开链SB，应考虑脊柱姿势和离轴腰椎反应力矩的差异以及对保持时间的潜在影响。
2b。
