Backpacks are common devices for carrying external posterior loads. However, relatively little is known about how these external loads affect the ability to recover from balance loss. In this exploratory investigation, 16 young adults (8 female, 8 male) performed forward and backward lean-and-release balance recovery trials, while wearing a backpack that was unloaded or loaded (at 15% of individual body weight). We quantified the effects of backpack loading on balance recovery in terms of maximum recoverable lean angles, center-of-mass kinematics, and temporal-spatial stepping characteristics. Mean values of maximum lean angles were 20° and 9° in response to forward and backward perturbations, respectively. These angles significantly decreased when wearing the additional load for only backward losses of balance. During backward losses of balance, the additional load decreased peak center-of-mass velocity and increased acceleration by ∼10 and 18% respectively, which was accompanied by ∼5% faster stepping responses and steps that were ∼9% longer, 11% higher, and had an ∼10% earlier onset. Thus, wearing a backpack decreases backward balance recovery ability and changes backward recovery stepping characteristics.

背包是用于携带外部后部负载的常见装置。然而，关于这些外部负载如何影响从平衡损失中恢复的能力，人们知之甚少。在这项探索性调查中，16 名年轻人（8 名女性，8 名男性）在背着未负重或负重（个人体重 15%）的背包时进行了向前和向后倾斜和释放平衡恢复试验。我们从最大可恢复倾斜角度、质心运动学和时空步进特性方面量化了背包负载对平衡恢复的影响。响应向前和向后扰动的最大倾斜角平均值分别为 20° 和 9°。当佩戴额外负载时，这些角度显着减小，仅导致向后失去平衡。在向后失去平衡期间，附加负载使峰值质心速度降低，加速度分别增加约 10% 和 18%，同时伴随着迈步响应加快约 5%，步长延长约 9%，高出 11% ，并且发病时间提前约 10%。因此，背负背包会降低向后平衡恢复能力并改变向后恢复迈步特性。