Movement smoothness in chronic post-stroke individuals walking in an outdoor environment—A cross-sectional study using IMU sensors

Abstract

Background Walking speed is often used in the clinic to assess the level of gait impairment following stroke. Nonetheless, post-stroke individuals may employ the same walking speed but at a distinct movement quality. The main objective of this study was to explore a novel movement quality metric, the estimation of gait smoothness by the spectral arc length (SPARC), in individuals with a chronic stroke displaying mild/moderate or severe motor impairment while walking in an outdoor environment. Also, to quantify the correlation between SPARC, gait speed, motor impairment, and lower limb spasticity focused on understanding the relationship between the movement smoothness metric and common clinical assessments. Methods Thirty-two individuals with a chronic stroke and 32 control subjects participated in this study. The 10 meters walking test (10 MWT) was performed at the self-selected speed in an outdoor environment. The 10 MWT was instrumented with an inertial measurement unit system (IMU), which afforded the extraction of trunk angular velocities (yaw, roll, and pitch) and subsequent SPARC calculation. Results Movement smoothness was not influenced by gait speed in the control group, indicating that SPARC may constitute an additional and independent metric in the gait assessment. Individuals with a chronic stroke displayed reduced smoothness in the yaw and roll angular velocities (lower SPARC) compared with the control group. Also, severely impaired participants presented greater variability in smoothness along the 10 MWT. In the stroke group, a smoother gait in the pitch angular velocity was correlated with lower limb spasticity, likely indicating adaptive use of spasticity to maintain the pendular walking mechanics. Conversely, reduced smoothness in the roll angular velocity was related to pronounced spasticity. Conclusions Individuals with a chronic stroke displayed reduced smoothness in the yaw and roll angular velocities while walking in an outdoor environment. The quantification of gait smoothness using the SPARC metric may represent an additional outcome in clinical assessments of gait in individuals with a chronic stroke.

Recent State of Wearable IMU Sensors Use in People Living with Spasticity: A Systematic Review

“…Table 1 shows the study and participant characteristics for all ten selected studies that used between one and seven IMU wearables for different purposes in people living with spasticity. Four studies [21,26,35,41] proposed a method or a framework for measurement of muscle spasticity level, and four other studies [37,39,40,42] focused on gait to calculate kinematic parameters in different environments (lab and real world). An additional study [38] investigated how severity of spasticity can affect quiet standing balance control, and another study [36] verified the relationship between commonly used clinical scales (FMA and MAS) and instrumented measurements.…”

“…The total population sample size ranged from 6 to 86, with reported spasticity severity between 0-4 (MAS) and included mixed genders in their experimental phase. Out of the ten studies, six studies included chronic stroke patients [36,[38][39][40][41][42], two studies included spinal cord injury patients [21,26], one study included multiple sclerosis patients [37], and another study included patients experiencing brain lesion [35]. Furthermore, while all selected studies reported either or both inclusion and excursion criteria, one study [41] did not explicitly account any of the study selection criteria based on these standards.…”

“…All studies clearly detailed their selected IMU brands. Seven studies [21,26,[35][36][37][38][39] out of ten reported their sampling frequency, which ranged between 30-1000 Hz. Three studies [36,39,40] used BTS G-Walk sensor, one study [35] used MPU9250, InvenSense, one study [21] used Shimmer Sensing, one study [37] used Actigraph GT3X, one study [38] used Sway Star, Balance International Innovations GmbH, one study used [41] used APDM Opal, and one study [42] the RehaGait Pro Analyzer sensor.…”

Possibility that extensors respond faster than flexors for the metacarpophalangeal joints in individuals with severe-to-moderate stroke-caused impairment: A pilot study

“…The spectral arc length was employed to evaluate the smoothness of the movement of the MCP joints [26], [27]. Computation of the spectral arc length is carried out based on the angular velocity profile of the MCP joints 𝜔 𝑀𝐶𝑃 (𝑡) as…”

Lower Limb Kinematic Coordination during the Running Motion of Stroke Patient: A Single Case Study

“…Secondly, it is also interesting to note that the peak of coherence was observed in the stroke patient and was not seen in the healthy subject. It has been shown that in rhythmic movements, such as human walking, the frequencies of body acceleration are usually observed in the lower range [ 29 ]. Considering that higher frequencies are observed in pathological subject, it is also interesting to note that a peak in coherence was observed in stroke patient, but not in healthy subject.…”