Hendershot Brad D, Shojaei Iman, Acasio Julian C, Dearth Christopher L, Bazrgari Babak
DoD-VA Extremity Trauma and Amputation Center of Excellence, Bethesda, MD, USA; Research and Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA; Department of Rehabilitation Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA.
J Biomech. 2018 Mar 21;70:249-254. doi: 10.1016/j.jbiomech.2017.11.026. Epub 2017 Nov 28.
Persons with lower limb amputation (LLA) perceive altered motions of the trunk/pelvis during activities of daily living as contributing factors for low back pain. When walking (at a singular speed), larger trunk motions among persons with vs. without LLA are associated with larger spinal loads; however, modulating walking speed is necessary in daily life and thus understanding the influences of walking speed on spinal loads in persons with LLA is of particular interest here. Three-dimensional trunk-pelvic kinematics, collected during level-ground walking at self-selected (SSW) and two controlled speeds (∼1.0 and ∼1.4 m/s), were obtained for seventy-eight participants: 26 with transfemoral and 26 with transtibial amputation, and 26 uninjured controls (CTR). Using a kinematics-driven, non-linear finite element model of the lower back, the resultant compressive and mediolateral/anteroposterior shear loads at the L5/S1 spinal level were estimated. Peak values were extracted and compiled. Despite walking slower at SSW speeds (∼0.21 m/s), spinal loads were 8-14% larger among persons with transfemoral amputation vs. CTR. Across all participants, peak compressive, mediolateral, and anteroposterior shear loads increased with increasing walking speed. At the fastest (vs. slowest) controlled speed, these increases were respectively 24-84% and 29-77% larger among persons with LLA relative to CTR. Over time, repeated exposures to these increased spinal loads, particularly at faster walking speeds, may contribute to the elevated risk for low back pain among persons with LLA. Future work should more completely characterize relative risk in daily life between persons with vs. without LLA by analyzing additional activities and tissue-level responses.
下肢截肢者在日常生活活动中察觉到躯干/骨盆运动改变是导致腰痛的因素。行走时（以单一速度），与未截肢者相比，下肢截肢者更大的躯干运动与更大的脊柱负荷相关；然而，在日常生活中调节步行速度是必要的，因此了解步行速度对下肢截肢者脊柱负荷的影响在此尤为重要。对78名参与者进行了三维躯干 - 骨盆运动学测量，这些测量是在自选速度（SSW）和平地行走时以及两个受控速度（约1.0和约1.4米/秒）下进行的：26名经股骨截肢者、26名经胫骨截肢者和26名未受伤的对照组（CTR）。使用腰部运动学驱动的非线性有限元模型，估计了L5/S1脊柱水平处的合成压缩和内外侧/前后剪切负荷。提取并汇总了峰值。尽管在SSW速度（约0.21米/秒）下行走较慢，但经股骨截肢者的脊柱负荷比对照组大8 - 14%。在所有参与者中，峰值压缩、内外侧和前后剪切负荷随着步行速度的增加而增加。在最快（与最慢）的受控速度下，相对于对照组，下肢截肢者的这些增加分别大24 - 84%和29 - 77%。随着时间的推移，反复暴露于这些增加的脊柱负荷，特别是在较快的步行速度下，可能会导致下肢截肢者患腰痛的风险增加。未来的工作应该通过分析更多活动和组织水平反应，更全面地描述下肢截肢者与未截肢者在日常生活中的相对风险。
