Exposure to an extreme environment comes at a sensorimotor cost

Abstract

Long duration space flight is known to induce severe modifications in the sensorimotor and musculoskeletal systems. While in-flight strategies including physical fitness have been used to prevent the loss of bone and muscle mass using appropriate rehabilitative countermeasures, less attention has been put forth in the design of technologies that can quickly and effectively assess sensorimotor function during missions in space. The aims of the present study were therefore (1) to develop a Portable Sensorimotor Assessment Platform (PSAP) to enable a crewmember to independently and quickly assess his/her sensorimotor function during the NASA’s Extreme Environment Mission Operations (NEEMO) and (2) to investigate changes in performance of static posture, tandem gait, and lower limb ataxia due to exposure in an extreme environment. Our data reveal that measuring the degree of upper body balance and gait regularity during tandem walking using PSAP provided a sensitive and objective quantification of body movement abnormalities due to changes in sensorimotor performance over the duration of mission exposure.

Using Inertial Sensors to Quantify Postural Sway and Gait Performance during the Tandem Walking Test

“…We calculated each ML displacement by double integration with high-pass filtering of the resulting acceleration from sensors donned at the head, upper trunk, and pelvis, respectively [25,30]. The amount of ML displacement was quantified by the area under the ML displacement curve [27]. In this study, an increase in the area indicated decreased upper body balance control [31].…”

“…Specifically, we measured the sagittal plane angular velocities from each ankle (gyroscope), defined as a rotation in the sagittal plane. The data was then processed and interpreted through the dynamic time warping (DTW)-based algorithm [27] that precisely quantifies the movement difference of each gait stride signal during TW.…”

“…Monitoring lower limb movements during TW may also provide useful information in assessing gait regularity, which may be more irregular in patients with vestibular dysfunction due to inaccuracies processing spatial afference compared with those of the healthy individuals [26]. Recently, we quantified the range of upper body sway by measuring medio–lateral (ML) displacements at the head, trunk, and pelvis during TW [27]. We also developed a novel method to detect slight changes in gait repeatability via sensors donned at both ankles during TW [27].…”

“…Recently, we quantified the range of upper body sway by measuring medio–lateral (ML) displacements at the head, trunk, and pelvis during TW [27]. We also developed a novel method to detect slight changes in gait repeatability via sensors donned at both ankles during TW [27].…”

Vestibular physical therapy improves turning not straight walking during the inertial sensor-instrumented Timed Up and Go test

“…Participants completed questionnaires regarding demographic information. The body worn sensor system that we currently use is comprised of five wireless MTw IMUs, Xsens shirt, and Velcro straps (Xsens Technologies, Netherlands) [26][27][28]. In this study, acceleration and angular velocities along three perpendicular axes data were analyzed from three IMUs (chest and each ankle) during the TUG test.…”