Excessive loads on the human spine is recognized as a risk factor for back injuries/pain. Various lifting analysis tools such as musculoskeletal models, regression equations and NIOSH (National Institute for Occupational Safety and Health) lifting equation (NLE) have been proposed to evaluate and mitigate associated risks during manual material handling activities. Present study aims to compare predicted spinal loads from 5 different lifting analysis tools as well as to critically evaluate the NIOSH recommended weight limit (RWL). Spinal loads were estimated under different symmetric/asymmetric lifting tasks in which hand-load mass at each task was set based on RWL from NLE. Estimated intradiscal pressures (IDPs) of various tools were also compared with in vivo measurements. We compared RWL by NLE versus our estimations of RWL calculated from our regression equations using biomechanical criteria (compression <3400 N with/without shear <1000, 1250 or 1500 N). Our regression equations followed by OpenSim, AnyBody, simple polynomial and 3DSSPP satisfactorily predicted L4-L5 IDPs. Lifting analysis tools estimated comparable spinal compression forces (mean Pearson’s r = 0.80; standard deviation of relative difference = 26%) while in shear, differences were greater (mean Pearson’s r = 0.68; standard deviation of relative difference = 56%). NLE estimations of RWL were conservative in comparison with our estimations for lean individuals (BMI < 25 kg/m²) when compression <3400 N and shear <1250 N were considered as the biomechanical criteria. For heavier individuals, however, NLE estimations of RWL generated spinal compression >3400 N (NIOSH biomechanical safety threshold) as well as shear >1000 N. Although RWLs estimated by NLE was body weight independent, body weight substantially altered RWLs estimated from our regression equations. For improved estimation of the risk of injury, more accurate failure criteria for spinal segments are essential.

人体脊柱上的过度负荷被认为是背部受伤/疼痛的危险因素。已经提出了各种举升分析工具，例如肌肉骨骼模型，回归方程和NIOSH（国家职业安全与健康研究所）举升方程（NLE），以评估和减轻人工物料搬运活动中的相关风险。本研究旨在比较5种不同举重分析工具预测的脊柱负荷，并严格评估NIOSH建议的体重限制（RWL）。在不同的对称/非对称提升任务下估算脊柱负荷，其中根据NLE的RWL设置每个任务的手负荷质量。还比较了各种工具的估计椎间盘内压力（IDP）与体内测量。我们将NLE的RWL与我们根据回归方程使用生物力学标准（压缩力<3400 N，有/无剪切力<1000、1250或1500 N）计算出的RWL进行了比较。OpenSim，AnyBody，简单多项式和3DSSPP之后的回归方程令人满意地预测了L4-L5 IDP。举升分析工具估算出可比的脊椎压缩力（平均皮尔森r = 0.80；相对差异的标准偏差= 26％），而在剪切力下，差异更大（平均皮尔森r = 0.68；相对差异的标准偏差= 56％）。与我们对瘦肉者的估计值相比（BMI <25 kg / m ²），将压缩力<3400 N和剪切力<1250 N视为生物力学标准。但是，对于较重的个体，RLE的NLE估计会产生大于3400 N（NIOSH生物力学安全阈值）的脊柱压缩，并且剪切力会大于1000N。尽管NLE估计的RWL与体重无关，但是体重大大改变了根据我们的回归方程估算的RWL 。为了更好地估计受伤的风险，更准确的脊柱节段破坏标准至关重要。