Deng Chen, Gillette Jason C, Derrick Timothy R
1 Iowa State University.
J Appl Biomech. 2018 Jun 1;34(3):191-198. doi: 10.1123/jab.2017-0122. Epub 2018 Jun 11.
A detailed understanding of the hip loading environment is needed to help prevent hip fractures, minimize hip pain, rehabilitate hip injuries, and design osteogenic exercises for the hip. The purpose of this study was to compare femoral neck stress during stair ascent and descent and to identify the contribution of muscles and reaction forces to the stress environment in mature adult subjects (n = 17; age: 50-65 y). Motion analysis and inverse dynamics were combined with musculoskeletal modeling and optimization, then used as input to an elliptical femoral neck cross-sectional model to estimate femoral neck stress. Peak stress values at the 2 peaks of the bimodal stress curves (stress vs time plot) were compared between stair ascent and descent. Stair ascent had greater compressive stress than descent during the first peak at the anterior (ascent: -18.0 [7.9] MPa, descent: -12.9 [5.4] MPa, P < .001) and posterior (ascent: -34.4 [10.9] MPa, descent: -27.8 [10.1] MPa, P < .001) aspects of the femoral neck cross section. Stair descent had greater tensile stress during both peaks at the superior aspect (ascent: 1.3 [7.0] MPa, descent: 24.8 [9.7] MPa, peak 1: P < .001; ascent: 15.7 [6.1] MPa, descent: 18.0 [8.4] MPa, peak 2: P = .03) and greater compressive stress during the second peak at the inferior aspect (ascent: -43.8 [9.7] MPa, descent: -51.1 [14.3] MPa, P = .004). Understanding this information can provide a more comprehensive view of bone loading at the femoral neck for older population.
为了帮助预防髋部骨折、减轻髋部疼痛、康复髋部损伤以及设计髋部成骨锻炼，需要对髋部负荷环境有详细的了解。本研究的目的是比较成年人（n = 17；年龄：50 - 65岁）上下楼梯时股骨颈应力，并确定肌肉和反作用力对应力环境的贡献。将运动分析和逆动力学与肌肉骨骼建模及优化相结合，然后将其作为输入应用于椭圆形股骨颈横截面模型以估计股骨颈应力。比较上下楼梯时双峰应力曲线（应力与时间图）两个峰值处的峰值应力值。在股骨颈横截面的前部，上楼梯时第一个峰值处的压应力大于下楼梯时（上楼梯：-18.0 [7.9] MPa，下楼梯：-12.9 [5.4] MPa，P < .001）；在后部，上楼梯时第一个峰值处的压应力也大于下楼梯时（上楼梯：-34.4 [10.9] MPa，下楼梯：-27.8 [10.1] MPa，P < .001）。在下楼梯时，股骨颈横截面 superior 面两个峰值处的拉应力均大于上楼梯时（第一个峰值：上楼梯：1.3 [7.0] MPa，下楼梯：24.8 [9.7] MPa，P < .001；第二个峰值：上楼梯：15.7 [6.1] MPa，下楼梯：18.0 [8.4] MPa，P = .03）；在 inferior 面，下楼梯时第二个峰值处的压应力大于上楼梯时（上楼梯：-43.8 [9.7] MPa，下楼梯：-51.1 [14.3] MPa，P = .004）。了解这些信息可以为老年人群股骨颈的骨负荷提供更全面的认识。
