Reeves N Peter, Sal Y Rosas Celi Victor Giancarlo, Ramadan Ahmed, Popovich John M, Radcliffe Clark J, Choi Jongeun, Cholewicki Jacek
Sumaq Life LLC, East Lansing, MI, USA; MSU Center for Orthopedic Research, Michigan State University, Lansing, MI, USA.
Sección de Matemáticas, Departamento de Ciencias, Pontificia Universidad Católica del Perú, Peru.
J Biomech. 2020 Nov 9;112:110038. doi: 10.1016/j.jbiomech.2020.110038. Epub 2020 Sep 9.
Performance during seated balancing is often used to assess trunk neuromuscular control, including evaluating impairments in back pain populations. Balancing in less challenging environments allows for flexibility in control, which may not depend on health status but instead may reflect personal preferences. To make assessment less ambiguous, trunk neuromuscular control should be maximally challenged. Thirty-four healthy subjects balanced on a robotic seat capable of adjusting rotational stiffness. Subjects balanced while rotational stiffness was gradually reduced. The rotational stiffness at which subjects could no longer maintain balance, defined as critical stiffness (k), was used to quantify the subjects' trunk neuromuscular control. A higher k reflects poorer control, as subjects require a more stable base to balance. Subjects were tested on three days separated by 24 hours to assess test-retest reliability. Anthropometric (height and weight) and demographic (age and sex) influences on k and its reliability were assessed. Height and age did not affect k; whereas, being heavier (p < 0.001) and female (p = 0.042) significantly increased k. Reliability was also affected by anthropometric and demographic factors, highlighting the potential problem of inflated reliability estimates from non-control related attributes. k measurements appear reliable even after removing anthropometric and demographic influences, with adjusted correlations of 0.612 (95%CI: 0.433-0.766) versus unadjusted correlations of 0.880 (95%CI: 0.797-0.932). Besides assessment, trainers and therapists prescribing exercise could use the seated balance task and k to precisely set difficulty level to a percentage of the subject's stability threshold to optimize improvements in trunk neuromuscular control and spine health.
坐位平衡表现常被用于评估躯干神经肌肉控制能力，包括评估背痛人群的功能障碍。在挑战性较小的环境中进行平衡测试，可以在控制方面提供灵活性，这可能不取决于健康状况，而可能反映个人偏好。为了使评估更明确，应最大限度地挑战躯干神经肌肉控制能力。34名健康受试者在一个能够调节旋转刚度的机器人座椅上进行平衡测试。受试者在旋转刚度逐渐降低的情况下保持平衡。将受试者无法再保持平衡时的旋转刚度定义为临界刚度（k），用于量化受试者的躯干神经肌肉控制能力。较高的k值反映了较差的控制能力，因为受试者需要更稳定的基础来保持平衡。受试者在相隔24小时的三天内接受测试，以评估重测信度。评估了人体测量学（身高和体重）和人口统计学（年龄和性别）对k值及其信度的影响。身高和年龄不影响k值；然而，体重较重（p<0.001）和女性（p=0.042）会显著增加k值。信度也受到人体测量学和人口统计学因素的影响，这突出了非控制相关属性导致信度估计值虚高的潜在问题。即使去除人体测量学和人口统计学影响，k值测量似乎仍然可靠，调整后的相关性为0.612（95%CI：0.433-0.766），而未调整的相关性为0.880（95%CI：0.797-0.932）。除了评估之外，开运动处方的教练和治疗师可以使用坐位平衡任务和k值，将难度水平精确设置为受试者稳定阈值的一定百分比，以优化躯干神经肌肉控制和脊柱健康状况的改善。
