Abstract：
UNASSIGNED: It is known that even under static conditions a backpack wearer will need to make some adjustments to maintain postural stability. There is a paucity of research exploring the impact of altering the position of the feet with imposed loads of variable distance from the posterior midline.
UNASSIGNED: Therefore, the aim of this study was to determine if changes in the horizontal position of a fixed load when wearing a backpack affect specific variables derived from foot tracings of males and females standing with their self-selected natural feet position.
UNASSIGNED: 150 healthy volunteer participants were instructed to adopt a natural stance across four conditions: Backpack with no weight, backpack with a weight (5% of body mass) placed at 0 cm, 20 cm, and 40 cm distance from the posterior body. Foot tracings were made for each condition. Base of Support (BoS), Feet Width (FW), and Feet Opening Angle (FOA) were calculated.
UNASSIGNED: The BoS significantly decreased in loaded conditions (0 cm, 20 cm and 40 cm) compared to unloaded. This was supported by FW and FOA significant findings that once the load was imposed the response was to approximate the feet and reduce \'toeout\'.
UNASSIGNED: This reaction of people to reduce their BoS in response to added backpack load appears counter intuitive and raises the question of whether this is maladaptive. Clarification by further investigation will inform backpack wearers to counter this instinctive response to load and increase postural stability.
UNASSIGNED: Therefore, the aim of this study was to determine if changes in the horizontal position of a fixed load when wearing a backpack affect specific variables derived from foot tracings of males and females standing with their self-selected natural feet position.
UNASSIGNED: 150 healthy volunteer participants were instructed to adopt a natural stance across four conditions: Backpack with no weight, backpack with a weight (5% of body mass) placed at 0 cm, 20 cm, and 40 cm distance from the posterior body. Foot tracings were made for each condition. Base of Support (BoS), Feet Width (FW), and Feet Opening Angle (FOA) were calculated.
UNASSIGNED: The BoS significantly decreased in loaded conditions (0 cm, 20 cm and 40 cm) compared to unloaded. This was supported by FW and FOA significant findings that once the load was imposed the response was to approximate the feet and reduce \'toeout\'.
UNASSIGNED: This reaction of people to reduce their BoS in response to added backpack load appears counter intuitive and raises the question of whether this is maladaptive. Clarification by further investigation will inform backpack wearers to counter this instinctive response to load and increase postural stability.
摘要：
■众所周知，即使在静态条件下，背包佩戴者也需要进行一些调整以保持姿势稳定性。很少有研究探索改变脚的位置与后中线距离可变的外加载荷的影响。
■因此，这项研究的目的是确定佩戴背包时固定负荷水平位置的变化是否会影响从男性和女性以自己选择的自然脚位站立的脚迹中得出的特定变量。
■150名健康志愿者被指示在四个条件下采取自然的姿态：无重量的背包，重量（体重的5％）的背包放置在0厘米处，20厘米，和40厘米的距离后体。针对每种条件进行足部描迹。支持基础(BoS)英尺宽度(FW),并计算开脚角度(FOA)。
■在负载条件下BoS显着下降（0厘米，20厘米和40厘米）与卸载相比。FW和FOA的重要发现支持了这一点，即一旦施加负荷，反应就是接近脚并减少“脚趾”。
■人们为应对增加的背包负荷而减少BoS的这种反应似乎与直觉相反，并提出了这是否是适应不良的问题。通过进一步调查的澄清将告知背包佩戴者应对这种对负载的本能反应并增加姿势稳定性。
■因此，这项研究的目的是确定佩戴背包时固定负荷水平位置的变化是否会影响从男性和女性以自己选择的自然脚位站立的脚迹中得出的特定变量。
■150名健康志愿者被指示在四个条件下采取自然的姿态：无重量的背包，重量（体重的5％）的背包放置在0厘米处，20厘米，和40厘米的距离后体。针对每种条件进行足部描迹。支持基础(BoS)英尺宽度(FW),并计算开脚角度(FOA)。
■在负载条件下BoS显着下降（0厘米，20厘米和40厘米）与卸载相比。FW和FOA的重要发现支持了这一点，即一旦施加负荷，反应就是接近脚并减少“脚趾”。
■人们为应对增加的背包负荷而减少BoS的这种反应似乎与直觉相反，并提出了这是否是适应不良的问题。通过进一步调查的澄清将告知背包佩戴者应对这种对负载的本能反应并增加姿势稳定性。
