Chung Jinwon, Quirk D Adam, Cherin Jason M, Friedrich Dennis, Kim Daekyum, Walsh Conor J
John a. Paulson School of Engineering and Applied Sciences, Harvard University, Boston, MA, USA.
School of Mechanical Engineering, Korea University, Seoul, South Korea.
Sci Rep. 2025 Mar 29;15(1):10929. doi: 10.1038/s41598-025-94726-3.
Back exoskeletons are gaining attention for preventing occupational back injuries, but they can disrupt movement, a burden that risks abandonment. Enhanced adaptability is proposed to mitigate burdens, but perceptual benefits are less known. This study investigates the perceptual and biomechanical impacts of a SLACK suit (non-assistive) controller versus three controllers with varying adaptability: a Weight-Direction-Angle adaptive (WDA-ADPT) that scales assistance based on the weight of the boxes using a chest-mounted camera and machine learning algorithm, movement direction, and trunk flexion angle, and standard Direction-Angle adaptive (DA-ADPT) and Angle adaptive (A-ADPT) controllers. Fifteen participants performed a variable weight (2, 8, 14 kg) box-transfer task. WDA-ADPT achieved the highest perceptual score (88%) across survey categories and reduced peak back extensor (BE) muscle amplitudes by 10.1%. DA-ADPT had slightly lower perceptual (76%) and peak BE reduction (8.5%). A-ADPT induced hip restriction, which could explain the lowest perceptual score (55%) despite providing the largest reductions in peak BE muscle activity (17.3%). Reduced perceptual scores achieved by DA and A-ADPT were explained by controllers providing too much or little assistance versus actual task demands. These findings underscore that scaling assistance to task demands improves biomechanical benefits and the perception of the device's suitability.
背部外骨骼在预防职业性背部损伤方面正受到关注，但它们可能会干扰动作，这种负担存在被弃用的风险。有人提出增强适应性以减轻负担，但感知益处却鲜为人知。本研究调查了SLACK套装（非辅助型）控制器与三种具有不同适应性的控制器在感知和生物力学方面的影响：一种重量-方向-角度自适应（WDA-ADPT）控制器，它使用安装在胸部的摄像头和机器学习算法，根据箱子的重量、移动方向和躯干屈曲角度来调整辅助力度；以及标准的方向-角度自适应（DA-ADPT）和角度自适应（A-ADPT）控制器。15名参与者完成了一项可变重量（2、8、14千克）的箱子搬运任务。WDA-ADPT在所有调查类别中获得了最高的感知评分（88%），并使背部伸肌（BE）肌肉的峰值幅度降低了10.1%。DA-ADPT的感知评分略低（76%），BE峰值降低幅度也较小（8.5%）。A-ADPT导致了髋关节受限，这可以解释尽管它使BE肌肉活动的峰值降低幅度最大（17.3%），但其感知评分却最低（55%）。DA-ADPT和A-ADPT获得较低感知评分的原因是，与实际任务需求相比，控制器提供的辅助过多或过少。这些发现强调，根据任务需求调整辅助力度可改善生物力学益处以及对设备适用性的感知。
