Laboratory for Neuromechanics and Biorobotics, Jožef Stefan Institute, Department of Automatics, Biocybernetics and Robotics, Ljubljana, Slovenia.
Jožef Stefan International Postgraduate School, Ljubljana, Slovenia.
Front Neural Circuits. 2021 Dec 14;15:750176. doi: 10.3389/fncir.2021.750176. eCollection 2021.
The human sensorimotor control has evolved in the Earth's environment where all movement is influenced by the gravitational force. Changes in this environmental force can severely impact the performance of arm movements which can be detrimental in completing certain tasks such as piloting or controlling complex vehicles. For this reason, subjects that are required to perform such tasks undergo extensive training procedures in order to minimize the chances of failure. We investigated whether local gravity simulation of altered gravitational conditions on the arm would lead to changes in kinematic parameters comparable to the full-body experience of microgravity and hypergravity onboard a parabolic flight. To see if this would be a feasible approach for on-ground training of arm reaching movements in altered gravity conditions we developed a robotic device that was able to apply forces at the wrist in order to simulate micro- or hypergravity conditions for the arm while subjects performed pointing movements on a touch screen. We analyzed and compared the results of several kinematic parameters along with muscle activity using this system with data of the same subjects being fully exposed to microgravity and hypergravity conditions on a parabolic flight. Both in our simulation and in-flight, we observed a significant increase in movement durations in microgravity conditions and increased velocities in hypergravity for upward movements. Additionally, we noted a reduced accuracy of pointing both in-flight and in our simulation. These promising results suggest, that locally simulated altered gravity can elicit similar changes in some movement characteristics for arm reaching movements. This could potentially be exploited as a means of developing devices such as exoskeletons to aid in training individuals prior to undertaking tasks in changed gravitational conditions.
人类的感觉运动控制是在地球环境中进化而来的,在这种环境中,所有的运动都受到重力的影响。这种环境力的变化会严重影响手臂运动的性能,这可能会对完成某些任务造成不利影响,例如驾驶或控制复杂的车辆。出于这个原因,需要执行这些任务的受试者需要进行广泛的训练程序,以尽量减少失败的机会。我们研究了手臂局部重力模拟改变的重力条件是否会导致运动学参数的变化,这些变化与微重力和超重环境下在抛物线飞行中全身体验相当。为了研究这是否是一种可行的方法,以便在改变的重力条件下对地面手臂的伸展运动进行训练,我们开发了一种机器人设备,该设备能够在手腕处施加力,以模拟微重力或超重条件,同时受试者在触摸屏上进行指向运动。我们使用该系统分析和比较了几个运动学参数以及肌肉活动的结果,并将同一组受试者在抛物线飞行中完全暴露于微重力和超重条件下的数据进行了比较。在我们的模拟和飞行中,我们观察到微重力条件下运动持续时间显著增加,向上运动时超重条件下速度增加。此外,我们还注意到指向精度在飞行中和我们的模拟中都有所降低。这些有希望的结果表明,局部模拟的改变重力可以引起手臂伸展运动的某些运动特征的相似变化。这可能被用作开发设备的一种手段,例如外骨骼,以帮助个人在接受改变的重力条件下的任务之前进行训练。