Research and Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, Bethesda, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, USA.
F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, USA.
J Biomech. 2019 Oct 11;95:109316. doi: 10.1016/j.jbiomech.2019.109316. Epub 2019 Aug 19.
Larger trunk and pelvic motions in persons with (vs. without) lower limb amputation during activities of daily living (ADLs) adversely affect the mechanical demands on the lower back. Building on evidence that such altered motions result in larger spinal loads during level-ground walking, here we characterize trunk-pelvic motions, trunk muscle forces, and resultant spinal loads among sixteen males with unilateral, transfemoral amputation (TFA) walking at a self-selected speed both up ("upslope"; 1.06 ± 0.14 m/s) and down ("downslope"; 0.98 ± 0.20 m/s) a 10-degree ramp. Tri-planar trunk and pelvic motions were obtained (and ranges-of-motion [ROM] computed) as inputs for a non-linear finite element model of the spine to estimate global and local muscle (i.e., trunk movers and stabilizers, respectively) forces, and resultant spinal loads. Sagittal- (p = 0.001), frontal- (p = 0.004), and transverse-plane (p < 0.001) trunk ROM, and peak mediolateral shear (p = 0.011) and local muscle forces (p = 0.010) were larger (respectively 45, 35, 98, 70, and 11%) in upslope vs. downslope walking. Peak anteroposterior shear (p = 0.33), compression (p = 0.28), and global muscle (p = 0.35) forces were similar between inclinations. Compared to previous reports of persons with TFA walking on level ground, 5-60% larger anteroposterior and mediolateral shear observed here (despite ∼0.25 m/s slower walking speeds) suggest greater mechanical demands on the low back in sloped walking, particularly upslope. Continued characterization of trunk motions and spinal loads during ADLs support the notion that repeated exposures to these larger-than-normal (i.e., vs. level-ground walking in TFA and uninjured cohorts) spinal loads contribute to an increased risk for low back injury following lower limb amputation.
在日常生活活动（ADL）中，与下肢截肢者（vs. 无下肢截肢者）相比，更大的躯干和骨盆运动对下背部的机械需求产生不利影响。基于这样的证据，即这种改变的运动导致在平地行走时脊柱负荷更大，在这里我们描述了 16 名单侧股骨截肢（TFA）男性在以自我选择的速度在 10 度斜坡上上下坡（“上坡”；1.06±0.14 m/s）和下坡（“下坡”；0.98±0.20 m/s）行走时的躯干-骨盆运动、躯干肌肉力和脊柱负荷。获得了三平面躯干和骨盆运动（并计算了运动范围[ROM]），作为脊柱非线性有限元模型的输入，以估计全局和局部肌肉（即躯干运动者和稳定器）的力和脊柱负荷。矢状面（p=0.001）、额状面（p=0.004）和横切面（p<0.001）的躯干 ROM，以及峰值横向剪切（p=0.011）和局部肌肉力（p=0.010）在上坡行走中更大（分别为 45%、35%、98%、70%和 11%）。在倾斜度之间，峰值前后剪切（p=0.33）、压缩（p=0.28）和全局肌肉（p=0.35）力相似。与 TFA 平地行走的先前报告相比，尽管步行速度慢约 0.25 m/s，但这里观察到的前后和横向剪切增加了 5-60%（p=0.001），这表明在倾斜行走中对下背部的机械需求更大，尤其是在上坡行走时。在 ADL 期间对躯干运动和脊柱负荷的持续特征描述支持这样的观点，即反复暴露于这些大于正常水平（即 TFA 和未受伤队列的平地行走）的脊柱负荷会增加下肢截肢后下背部受伤的风险。
