Marras William S, Davis Kermit G, Jorgensen Michael
Biodynamics Laboratory, Institute for Ergonomics, Ohio State University, Columbus, Ohio 43210, USA.
Spine (Phila Pa 1976). 2002 Nov 15;27(22):2514-20. doi: 10.1097/00007632-200211150-00017.
In vivo laboratory studies were conducted to investigate the spine loads imposed on men and women during a series of lifting tasks that varied in the degree of lifting control required by the subject.
To identify and understand differences in spine loading and musculoskeletal control strategies between men and women performing lifts of varying task complexity.
Few studies have examined differences in spine loading as a function of individual factors such as subject gender. Furthermore, no biomechanical studies have attempted to quantify and understand how differences in anthropometry between genders might influence muscle recruitment and subsequent spine loads. Because the modern workplace seldom discriminates between genders in job assignments, it is important to understand how differences in spine loading and potential low back disorder risk might be associated with gender differences.
For this study, 140 subjects participated in two separate experiments requiring different degrees of musculoskeletal motion control during sagittal plane lifting. The two experiments consisted of 35 men and 35 women performing lifts in which motion was isolated to the torso and 35 men and 35 women completing whole-body free-dynamic whole body lifts. An electromyography-assisted model was used to evaluate spine loading under these conditions.
Absolute spine compression generally was greater for the men. Under the highly controlled (isolated torso) conditions, most differences were attributed solely to differences in body mass. Under a whole-body free-dynamic condition, significant differences in muscle coactivations resulted in greater relative compression and anterior-posterior shear spine loading for the women.
Differences in spine loadings as a function of gender under the more controlled lifting conditions were primarily a function of different body masses. However, loading pattern differences existed between the genders under whole-body free-dynamic conditions as a result of kinematic compensations and increases in muscle cocontraction, with women generally experiencing greater relative loads. When spine tolerance differences are considered, one would expect that females would be at greater risk of musculoskeletal overload during lifting tasks.
进行了体内实验室研究，以调查在一系列由受试者所需的提升控制程度不同的提升任务中，施加在男性和女性身上的脊柱负荷。
识别并理解执行不同任务复杂性提升动作的男性和女性在脊柱负荷和肌肉骨骼控制策略上的差异。
很少有研究考察脊柱负荷随个体因素（如受试者性别）的差异。此外，没有生物力学研究试图量化并理解性别之间人体测量学差异如何影响肌肉募集及随后的脊柱负荷。由于现代工作场所很少在工作分配上区分性别，了解脊柱负荷差异和潜在的下背痛风险如何与性别差异相关很重要。
在本研究中，140名受试者参与了两项单独的实验，这两项实验在矢状面提升过程中需要不同程度的肌肉骨骼运动控制。这两项实验包括35名男性和35名女性进行的提升动作，其中运动仅限于躯干，以及35名男性和35名女性完成的全身自由动态全身提升。在这些条件下，使用肌电图辅助模型评估脊柱负荷。
男性的绝对脊柱压缩通常更大。在高度受控（孤立躯干）条件下，大多数差异仅归因于体重差异。在全身自由动态条件下，肌肉共同激活的显著差异导致女性的相对压缩和脊柱前后剪切负荷更大。
在更受控的提升条件下，脊柱负荷随性别变化的差异主要是不同体重的作用。然而，在全身自由动态条件下，由于运动学补偿和肌肉协同收缩增加，性别之间存在负荷模式差异，女性通常承受更大的相对负荷。考虑到脊柱耐受性差异，人们会预期女性在提升任务期间肌肉骨骼过载的风险更大。
