Fall risk during opposing stance perturbations among healthy adults and chronic stroke survivors

Abstract

Studies examining recovery from SLIPS and TRIPS indicate higher incidence of falls during SLIPS than TRIPS however, differences in the recovery mechanisms during these opposing perturbations have not been examined. We therefore aimed to compare the reactive balance responses contributing to fall risk during SLIPS and TRIPS at comparable perturbation intensity among community-dwelling healthy adults and chronic stroke survivors. Younger adults (N = 11), age-matched adults (N = 11) and chronic stroke survivors (N = 12) were exposed to a single SLIP and TRIP through a motorized treadmill (16 m/s 0.20 m). Center of mass (COM) state stability was measured by recording COM position and velocity relative to base of support, i.e., Ḋ and Ẋ, respectively. Trunk and compensatory step kinematics were also recorded. During SLIPS, the incidence of falls among stroke survivors was greater than healthy adults (53.83% vs. 0%), however not for TRIPS. All groups showed higher change in postural stability from liftoff to touchdown during TRIPS than SLIPS. Among healthy adults higher change in Ḋ during TRIPS was accompanied by the ability to control trunk flexion at step touchdown and lower peak trunk velocity as compared with SLIPS, with no significant differences in compensatory step length between the perturbations (p> 0.05). Chronic stroke survivors increased compensatory step length during TRIPS versus SLIPS (p < 0.05) contributing to greater stability change. They were unable to control trunk excursion and peak trunk velocity as compared with the healthy adults leading to lower stability than healthy younger and age-matched adults during SLIPS and lower stability than younger adults during TRIPS. Difficulty in trunk control during SLIPS among all individuals and compensatory step length among stroke survivors emphasizes higher fall risk for SLIPS than TRIPS among these populations.

Correlation among triceps surae muscle structure, balance, and gait in persons with stroke

“…The FRT distance of the participants with stroke were 7.79% lower than that of healthy adults and the SLART distance was 24.52% lower. These results are similar to previous research findings, which suggested that it is difficult for patients with chronic stroke to secure stability in a static and dynamic balanced environment when compared with young adults and healthy adults of similar age [39].…”

Small Directional Treadmill Perturbations Induce Differential Gait Stability Adaptation

“…8A), we found that the stick perturbations had a stronger scaling effect than slip perturbations for the same increment (from 0.2 to 0.4). Backward instability created by belt decelerations (stick perturbations) tend to be more challenging than forward instability created by the belt accelerations (slip perturbations) (Patel and Bhatt 2018; Roeles et al 2018).…”

“…Perturbations during walking can induce potential losses of balance and elicit corrective locomotor adaptations, which are useful for understanding human balance control (Mansfield et al 2015; Torres-Oviedo et al 2011). There are multiple approaches to perturb gait stability, including split-belt walking (Buurke et al 2018; Torres-Oviedo et al 2011), visual flow distortions (Franz et al 2016; O’Connor and Kuo 2009), waist pulling (Hof et al 2010; Vlutters et al 2018), platform displacements (Afschrift et al 2018; McIntosh et al 2017), and rapid changes in treadmill belt speed (Debelle et al 2020; Patel and Bhatt 2018). Studies using discrete perturbations such as waist pulling, platform displacements, and changes in treadmill belt speeds often apply the perturbation once out of every 5-20 strides (Afschrift et al 2018; Debelle et al 2020; Hof et al 2010; McIntosh et al 2017; Patel and Bhatt 2018; Vlutters et al 2018).…”

Artificial Neural Network Analyzing Wearable Device Gait Data for Identifying Patients With Stroke Unable to Return to Work

“…In our study, the FSLR showed that a longer stance phase was associated to the identification of patients (OR = 1.547). The trunk kinematics was also reported as fundamental for the upright balance during walking in patients with stroke, being exposed to the risk of fall ( 23 , 24 ). The inertial measurement of trunk kinematics during walking is probably the most important factor associated to this dynamic balance ( 11 , 12 ).…”