Sheikh Aisha, Claramunt-Molet Mireia, Rudolf Karen, Migliorelli Carolina, Idelsohn-Zielonka Sebastian, Miralles Felip, Vissing John
Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen 2100, Denmark.
Unit of Digital Health, Eurecat, Centre Tecnològic de Catalunya, Barcelona 08005, Spain.
Brain Commun. 2025 Jun 5;7(3):fcaf205. doi: 10.1093/braincomms/fcaf205. eCollection 2025.
The 6-min walk test (6MWT) is commonly used to assess physical function and endurance. The purpose of this observational study was to test a newly developed biomechanical system, Ephion Mobility system, and establish whether these biomechanical measures can improve the objectivity and interpretability of the 6MWT as an outcome measure. Fifty-eight participants took part in this study: 20 participants with myotonic muscular dystrophy (DM1), 18 with Becker muscular dystrophy (BMD) and 20 healthy controls for comparison. Every DM1 participant was classified using Muscular Impairment Rating Scale, and every BMD participant was classified using the Vignos scale. Each participant performed the 6MWT while wearing the Ephion Mobility system sensors, which recorded walking distance, surface electromyography (sEMG), heart rate (HR), ground reaction force (GRF), trunk vertical acceleration and joint kinematics. Both patient groups exhibited significantly shorter walking distance, lower cadence and shorter step length. Lower HR was found in both patient groups; this increased as disease severity increased. Limited range of motion was observed during the entire walk test in both patient groups. The DM1 group showed gait alterations during toe-off with reduction in hip and knee extension and a delayed and reduced plantar flexion. As disease severity increased, visual interpretation of sEMG in the DM1 group exhibited lower amplitude in the proximal muscles. The BMD group exhibited gait alterations during contact, stance and toe-off phases. Flat foot landing was observed in the BMD group along with reduced hip flexion and ankle dorsiflexion. During stance, they were unable to extend the hip and flex the knee and muscle activity increased, and reduced plantarflexion was observed during toe-off. The GRF was lower during heel strike and higher during mid-stance, and trunk vertical acceleration was close to zero during the contact phase in both patient groups. A visual interpretation of the gait patterns showed differences among disease severity levels. Our findings show that the Ephion Mobility system can determine biomechanics during walking and is coupled with distinct patterns of walking in BMD and DM1. Ephion Mobility system is useful in obtaining observational differences among disease severities and may be responsive to progression or treatment-induced improvement. The system adds value to improving interpretability of the 6MWT and additionally be used in assessing other functional capabilities, such as sit-to-stand and stair climbing.
6分钟步行试验（6MWT）常用于评估身体功能和耐力。这项观察性研究的目的是测试一种新开发的生物力学系统——Ephion移动系统，并确定这些生物力学测量方法能否提高6MWT作为一项结果指标的客观性和可解释性。58名参与者参与了本研究：20名强直性肌营养不良（DM1）患者、18名贝克型肌营养不良（BMD）患者以及20名健康对照者用于比较。每位DM1参与者使用肌肉损伤评定量表进行分类，每位BMD参与者使用维格诺斯量表进行分类。每位参与者在佩戴Ephion移动系统传感器的情况下进行6MWT，该传感器记录步行距离、表面肌电图（sEMG）、心率（HR）、地面反作用力（GRF）、躯干垂直加速度和关节运动学数据。两个患者组的步行距离均显著缩短，步频降低，步长缩短。两个患者组的心率均较低；随着疾病严重程度的增加而升高。在整个步行试验过程中，两个患者组均观察到运动范围受限。DM1组在足趾离地时表现出步态改变，髋部和膝部伸展减少，跖屈延迟且幅度减小。随着疾病严重程度的增加，DM1组sEMG的视觉解读显示近端肌肉的振幅较低。BMD组在接触、站立和足趾离地阶段均表现出步态改变。BMD组观察到扁平足着地，同时髋部屈曲和踝关节背屈减少。在站立期间，他们无法伸展髋部和屈曲膝部，肌肉活动增加，在足趾离地时观察到跖屈减少。两个患者组在足跟撞击时GRF较低，在站立中期较高，在接触阶段躯干垂直加速度接近零。对步态模式的视觉解读显示疾病严重程度水平之间存在差异。我们的研究结果表明，Ephion移动系统可以确定步行过程中的生物力学，并且与BMD和DM1不同的步行模式相关。Ephion移动系统有助于获得疾病严重程度之间的观察性差异，并且可能对疾病进展或治疗引起的改善有反应。该系统为提高6MWT的可解释性增加了价值，还可用于评估其他功能能力，如从坐到站和爬楼梯。
