Lower extremity joint compensatory effects during the first recovery step following slipping and stumbling perturbations in young and older subjects

Abstract

Background The lower extremity may play a crucial role in compensating for gait perturbations. The study aimed to explore the mechanism of perturbation compensation by investigating the gait characteristics and lower extremity joint moment effects in young (YS) and older subjects (OS) during the first recovery gait following slipping (slipping_Rec1) and stumbling (stumbling_Rec1). Method An automatic perturbation-triggered program was developed using D-Flow software based on the Gait Real-time Analysis Interactive Lab to induce the two aforementioned perturbations. Marker trajectories and ground reaction forces were recorded from 15 healthy YS (age: 26.53 ± 3.04 years; body height: 1.73 ± 0.07 m; body mass: 66.81 ± 11.44 kg) and 15 healthy OS (age: 68.33 ± 3.29 years; body height: 1.76 ± 0.10 m; body mass: 81.13 ± 13.99 kg). The Human Body Model was used to compute the variables of interest. One-way analysis of variance and independent samples t-test statistical analyses were performed. Results In slipping_Rec1 and stumbling_Rec1, the change in gait pattern was mainly reflected in a significant increase in step width, no alterations in step length and stance/swing ratio were revealed. Based on perturbed task specificity, lower extremity joint moments increased or decreased at specific phases of the gait cycle in both YS and OS in slipping_Rec1 and stumbling_Rec1 compared to normal gait. The two perturbed gaits reflected the respective compensatory requirements for the lower extremity joints, with both sagittal and frontal joint moments producing compensatory effects. The aging effect was not reflected in the gait pattern, but rather in the hip extension moment during the initial stance of slipping_Rec1. Conclusions Slipping appears to be more demanding for gait recovery than stumbling. Gait perturbation compensatory mechanisms for OS should concentrate on ankle strategy in the frontal plane and counter-rotation strategy around the hip.

Immediate Effect Evaluation of a Robotic Ankle–Foot Orthosis with Customized Algorithm for a Foot Drop Patient: A Quantitative and Qualitative Case Report

“…Previously, the stance–swing ratio was 60% to 40%. After the robotic AFO assistance, the stance–swing ratio became 75% to 25%, which was farther than the normal stance–swing ratio of 60% to 40% [ 38 ]. The change in the stance–swing ratio occurred because of the shifted timing of the beginning of each gait phase, shown in Figure 3 .…”

“…The derivative walking gait data, such as the cadence, stance–swing ratio, and ankle ROM, have also been obtained. Ideally, a gait analyzer should be used to observe more comprehensive walking gait data, such as the knee–hip angle and joint moment [ 35 , 38 ]. Walking gait energy expenditure is also interesting because it can add more justification to the robotic AFO usage [ 39 ].…”

Reduced adaptability to balance perturbations in older adults with probable cognitive impairment after a severe fall

“…A poorer gait adaptability to balance perturbations in OACI is in line with previous research indicating differences in walking behavior between OACH and OACI [ 36 – 38 ]. As adapting step length is an important recovery mechanism to external perturbations [ 26 , 39 ], immediate changes of an individual’s step length to perturbations were expected. However, the increased number of recovery steps needed by OACI may indicate less effective stepping responses, especially as Debelle and colleagues argue that a close to normal step length after a perturbation may present an important component of balance recovery [ 31 ].…”

“…However, the increased number of recovery steps needed by OACI may indicate less effective stepping responses, especially as Debelle and colleagues argue that a close to normal step length after a perturbation may present an important component of balance recovery [ 31 ]. However, previous results are controversial whether a close to normal, a shortened first step length (i.e., higher walking stability) or an elongated first step (i.e., better compensation for shifts in center of mass) may present better reactions to perturbations [ 26 , 31 , 39 , 40 ]. Therefore, future research needs to target recovery mechanisms to different types and intensities of perturbations, to identify adequate recovery mechanisms and, thus, modify fall prevention efforts.…”

Young adults accelerate their arms significantly faster and earlier than old adults resulting in improved center of mass dynamics during an overground slip perturbation

“…Furthermore, it is reported that 56% of falls in older adults occur from stepping on a slippery surface and experiencing a slip (2). The majority of the biomechanical research on slip perturbations have focused on the lower extremities (4,5,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(6)(7)(8)(9)(10)(11)(12)(13). There are fewer investigations of the upper extremities during a slip incident as a consequence of focusing on the lower extremity responses (24)(25)(26)(27)(28)(29)(30).…”