Biology subjects

Nantel, J.

Publications and source records attributed to Nantel, J..

6 recordsLinked to original sources

bioRxiv2023

Smartwatch-based prediction of single-stride and stride-to-stride gait outcomes using regression-based machine learning

2.Abstract and key termsSpatiotemporal variability during gait is linked to fall risk and could be monitored using wearable sensors. Although many users prefer wrist-worn sensors, most applications position at other sites. We developed and evaluated an application using a consumer-grade smartwatch inertial measurement unit (IMU). Young adults (N = 41) completed seven-minute conditions of treadmill gait at three different speeds. Single-stride outcomes (stride time, length, width, and speed) and spatiotemporal variability (coefficient of variation of each single-stride outcome) were recorded using an optoelectronic system, while 232 single- and multi-stride IMU metrics were recorded using an Apple Watch Series 5. These metrics were input to train linear, ridge, support vector machine (SVM), random forest, and extreme gradient boosting (xGB) models of each spatiotemporal outcome. We conducted Model x Condition ANOVAs to explore model sensitivity to speed-related responses. xGB models were best for single-stride outcomes (relative mean absolute error [% error]: 7-11%; intraclass correlation coefficient [ICC2,1]: 0.60-0.86) and SVM models were best for spatiotemporal variability (% error: 18-22%; ICC2,1 = 0.47-0.64). Spatiotemporal changes with speed were captured by these models (Condition: p < 0.00625). Results support the feasibility of monitoring multi-stride spatiotemporal parameters using a smartwatch IMU and machine learning.

bioengineering↗

bioRxiv2022

Interlimb coordination in Parkinson's disease is affected by a visuospatial dual task

Parkinsons disease (PD) leads to reduced spatial and temporal interlimb coordination during gait as well as reduced coordination in the upper or lower limbs. Multi-tasking when walking is common during real-world activities, and affects some gait characteristics, like gait speed and variability. However, the impact of a dual task (DT) on intra and interlimb coordination of both lower and upper limbs when walking in people with PD remains unknown. Seventeen volunteers with mild to moderate PD (11 males, 65 {+/-} 8 years, 173 {+/-} 8 cm, 74 {+/-} 20 kg, Unified Parkinsons Disease Rating Scale motor section 10 {+/-} 5) participated in gait trials in an Extended-CAREN system, which includes a treadmill, 12-camera Vicon motion capture system, and a 180{degrees} field-of-view virtual reality projection screen. Participants completed a 3 min walking trial and a 2 min visuospatial word recognition DT trial at their preferred walking pace. Single and DT were compared with a paired t-test, and the less and more affected (LA, MA) sides were tested for equivalence in sensitivity to the DT. During the DT, we found the LA shoulder ROM decreased by 1.5{degrees}, and the LA shoulder peak flexion decreased by 1.1{degrees} (p<.028, gav>.12). The LA and MA hip ROM were differently affected by the dual task (p=.023), and intralimb coordination was affected by dual tasking equivalently between sides (p=.004). These results suggest that during normal single-task gait, people with PD use attentional resources to compensate for reduced arm swing. Furthermore, our results indicate that any effect of DT on lower intralimb coordination is not meaningfully different between the LA and MA sides. Statements and DeclarationsThe authors have no relevant financial or non-financial interests to disclose.

pathology↗

bioRxiv2021

Validity and sensitivity of an inertial measurement unit-driven biomechanical model of motor variability for gait

Motor variability in gait is frequently linked to fall risk, yet field-based biomechanical joint evaluations are scarce. We evaluated the validity and sensitivity of an inertial measurement unit (IMU)-driven biomechanical model of joint angle variability for gait. Fourteen healthy young adults completed seven-minute trials of treadmill gait at several speeds and arm swing amplitudes. Joint kinematics were estimated by IMU- and optoelectronic-based models using OpenSim. We calculated range of motion (ROM), magnitude of variability (meanSD), local dynamic stability ({lambda}max), persistence of ROM fluctuations (DFA), and regularity (SaEn) of each angle over 200 continuous strides, and evaluated model accuracy (e.g., RMSD: root mean square difference), consistency (ICC2,1: intraclass correlation), biases, limits of agreement, and sensitivity to within-participant gait responses (effects of Speed and Swing). RMSDs of joint angles were 1.7-7.5{degrees} (pooled mean of 4.8{degrees}), excluding ankle inversion. ICCs were mostly good- excellent in the primary plane of motion for ROM and in all planes for meanSD and {lambda}max, but were poor-moderate for DFA and SaEn. Modeled Speed and Swing responses for ROM, meanSD, and {lambda}max were similar. Results suggest that the IMU-driven model is valid and sensitive for field-based assessments of joint angles and several motor variability features.

bioengineering↗

bioRxiv2021

Effects of arm swing amplitude and lower limb asymmetry on motor variability patterns during treadmill gait

Motor variability is a fundamental feature of gait. Altered arm swing and lower limb asymmetry (LLA) may be contributing factors having been shown to affect the magnitude and dynamics of variability in spatiotemporal and trunk motion. However, the effects on lower limb joints remain unclear. Full-body kinematics of 15 healthy young adults were recorded during treadmill walking using the Computer-Assisted Rehabilitation Environment system. Participants completed six trials, combining three arm swing (AS) amplitude (normal, active, held) and two LLA (symmetrical, asymmetrical) conditions. The mean standard deviation (meanSD), maximum Lyapunov exponent ({lambda}max), detrended fluctuation analysis scaling exponent of range of motion (DFA), and sample entropy (SaEn) were computed for tridimensional trunk, pelvis, and lower limb joint angles, and compared using repeated-measures ANOVAs. Relative to normal AS, active AS increased meanSD of all joint angles, {lambda}max of frontal plane hip and ankle angles, and SaEn of sagittal plane ankle angles. Active AS, however, did not affect {lambda}max or SaEn of trunk or pelvis angles. LLA increased meanSD of sagittal plane joint angles, {lambda}max of Euclidean norm trunk angle and of lower limb joint angles, and SaEn of ankle dorsiflexion/ plantarflexion, but decreased SaEn of tridimensional trunk angles and hip rotation in the slower moving leg. Alterations in lower limb variability with active AS and LLA suggest that young adults actively exploit their lower limb redundancies to maintain gait. This appears to preserve trunk stability and regularity during active AS but not during LLA.

bioengineering↗

bioRxiv2021

Sensitivity of discrete symmetry metrics: implications for metric choice

Gait asymmetry is present in several pathological populations, including those with Parkinsons disease, Huntingtons disease, and stroke survivors. Previous studies suggest that commonly used discrete symmetry metrics, which compare single bilateral variables, may not be equally sensitive to underlying effects of asymmetry, and the use of a metric with low sensitivity could result in unnecessarily low statistical power. The purpose of this study was to provide a comprehensive assessment of the sensitivity of commonly used discrete symmetry metrics to better inform design of future studies. Monte Carlo simulations were used to estimate the statistical power of each symmetry metric at a range of asymmetry magnitudes, group/condition variabilities, and sample sizes. Power was estimated by repeated comparison of simulated symmetric and asymmetric data with a paired t-test, where the proportion of significant results is equivalent to the power. Simulation results confirmed that not all common discrete symmetry metrics are equally sensitive to reference effects of asymmetry. Multiple symmetry metrics exhibit equivalent sensitivities, but the most sensitive discrete symmetry metric in all cases is a bilateral difference (e.g. left - right). A ratio (e.g. left/right) has poor sensitivity when group/condition variability is not small, but a log-transformation produces increased sensitivity. Additionally, two metrics which included an absolute value in their definitions showed increased sensitivity when the absolute value was removed. Future studies should consider metric sensitivity when designing analyses to reduce the possibility of underpowered research. Summary statementStatistical power is an important factor in study design. Our results show that not all discrete symmetry metrics have similar or sufficient sensitivity to detect effects of asymmetry.

bioengineering↗

bioRxiv2019

The effects of arm swing amplitude and lower-limb asymmetry on gait stability

Changes to arm swing and gait symmetry are symptomatic of several pathological gaits associated with reduced stability. The purpose of this study was to examine the relative contributions of arm swing and gait symmetry towards gait stability. We theorized that actively increasing arm swing would increase gait stability, while asymmetric walking would decrease gait stability. Fifteen healthy, young adults (23.4 {+/-} 2.8 yrs) walked on a split-belt treadmill under symmetric (1.2 m/s) and asymmetric walking (left/right, 5:4 speed ratio) with three different arm swings: held, normal, and active. Trunk local dynamic stability, inter-limb coordination, and spatiotemporal gait variability and symmetry were measured. Active arm swing resulted in improved local trunk stability, increased gait variability, and decreased inter-limb coordination (p < .013). The changes in local trunk stability and gait variability during active arm swing suggests that these metrics quantify fundamentally different aspects of stability and are not always comparable. Split-belt walking caused reduced local trunk stability, increased gait variability, and increased lower limb asymmetry (p < .003). However, the arm swing symmetry was unaffected by gait asymmetry, this suggests that deficits in gait stability in pathological gaits may be linked to increases in gait asymmetry rather than increases in arm swing asymmetry.

neuroscience↗