Musculoskeletal injuries of the lumbar spine occur frequently among military service members and are associated with heavy backpack loads. Musculoskeletal modeling and simulation facilitate biomechanical evaluation to compare different backpack designs. We developed a backpack attachment model that can be tuned to represent various load distributions between the torso and pelvis. We generated walking simulations to estimate muscle and joint contact forces of unloaded walking and while carrying 38 kg using shoulder-borne backpacks and hip belt-assisted backpacks for six U.S. Marines. Three-dimensional peak and average lumbar (L4-L5) and hip joint contact forces over the stance phase were compared between each load condition. Axial L4-L5 and axial and anterior hip joint contact forces were greater during both backpack conditions compared to the unloaded condition. Joint contact forces were similar between backpack conditions. Future studies incorporating additional participants, walking conditions, and backpack load distributions are suggested for further model development and backpack design evaluation.

腰椎的肌肉骨骼损伤在军人中经常发生，并且与沉重的背包负荷有关。肌肉骨骼建模和模拟有助于生物力学评估，以比较不同的背包设计。我们开发了一个背包附件模型，可以调整它来表示躯干和骨盆之间的各种负载分布。我们生成了步行模拟，以估计六名美国海军陆战队使用肩扛背包和腰带辅助背包在空载步行和携带 38 公斤重物时的肌肉和关节接触力。在每个负载条件之间比较了站立阶段的三维峰值和平均腰椎 (L4-L5) 和髋关节接触力。与空载条件相比，在两种背包条件下，轴向 L4-L5 以及轴向和前髋关节接触力都更大。背包条件下的关节接触力相似。建议未来的研究包括额外的参与者、步行条件和背包负载分布，以进行进一步的模型开发和背包设计评估。