New assistive walker improved local dynamic stability in young healthy adults

Direct biomechanical manipulation of human gait stability: A systematic review

People fall more often when their gait stability is reduced. Gait stability can be directly manipulated by exerting forces or moments onto a person, ranging from simple walking sticks to complex wearable robotics. A systematic review of the literature was performed to determine: What is the level of evidence for different types of mechanical manipulations on improving gait stability? The study was registered at PROSPERO (CRD42020180631). Databases Embase, Medline All, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and Google Scholar were searched. The final search was conducted on the 1st of December, 2022. The included studies contained mechanical devices that influence gait stability for both impaired and non-impaired subjects. Studies performed with prosthetic devices, passive orthoses, and analysing post-training effects were excluded. An adapted NIH quality assessment tool was used to assess the study quality and risk of bias. Studies were grouped based on the type of device, point of application, and direction of forces and moments. For each device type, a best-evidence synthesis was performed to quantify the level of evidence based on the type of validity of the reported outcome measures and the study quality assessment score. Impaired and non-impaired study participants were considered separately. From a total of 4701 papers, 53 were included in our analysis. For impaired subjects, indicative evidence was found for medio-lateral pelvis stabilisation for improving gait stability, while limited evidence was found for hip joint assistance and canes. For non-impaired subjects, moderate evidence was found for medio-lateral pelvis stabilisation and limited evidence for body weight support. For all other device types, either indicative or insufficient evidence was found for improving gait stability. Our findings also highlight the lack of consensus on outcome measures amongst studies of devices focused on manipulating gait.

Users' adaptations to the proportional speed control of a motorised walker

PURPOSE

Speed control is commonly used to regulate the forces applied by motorised walkers (MW) and there are often situations where the speed targeted deviates from the preferred walking speed of its users, such as when encouraging higher walking speeds and due to safety consideration. This study investigates the effects of different MW's target speeds on the selected walking speeds, force applied, perceived exertion, and gait of MW users during steady-state walking.

MATERIALS AND METHODS

The spatiotemporal gait parameters and perceived exertion of twenty young healthy participants were measured as they walked at a comfortable, self-selected speed using a MW as it was controlled to target forward speeds of 0.6, 0.8, 1.0, 1.2, and 1.4 m s-1 as well as when no assistive force was applied by the MW.

RESULTS

On average, users would walk slower when their "No Assist" walking speed is higher than the MW's speed target and vice versa. Additionally, the force applied to the MW is proportional to the difference in speed, either faster or slower, when compared to "No Assist".

CONCLUSION

The user's exertion and the energy used by the MW are both minimised when target speed is close to the preferred walking speed of the user. Additionally, these findings suggest that the speed target can be used to change the walking speed of users but only to a certain extend and at the cost of higher perceived exertion.Implications for rehabilitationThe larger the difference between the target speed of the MW and the preferred walking speed of the user, the more likely the user is to push or pull on the MW.Users would push or pull on the MW with a force proportional to the difference from their preferred walking speed even when matching the MW's target speed.Users can be encouraged to walk at higher than preferred speeds, even though this would come at the cost of higher perceived exertion.

The effect of first-time 4-wheeled walker use on the gait of younger and older adults

INTRODUCTION

The 4-wheeled walker is intended to enhance balance and gait for older adults. Yet, some research suggests that walking aids increase falls risk. An understanding of the influence of age with walker use on gait performance is required.

OBJECTIVE

To examine the effect of initial 4-wheeled walker use on spatiotemporal gait parameters between younger and older adults.

DESIGN

Cross-sectional, repeated-measures.

SETTING

Community-dwelling.

PARTICIPANTS

Twenty-five younger (age: 26.5 ± 4.1 years) and 24 older (age: 68.5 ± 10.5 years) adults participated. Younger adults were aged 18 to 35 years, whereas older adults were 50 years or older. Included were people not requiring the use of a walking aid, and those able to converse in English.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE(S)

Gait velocity and stride time variability were recorded using accelerometers. Gait was examined under three conditions: unassisted walking; walking with a 4-wheeled walker; and walking with a 4-wheeled walker while completing a secondary task. Conditions were performed across two walking paths: straight and figure-of-8 Walk Test. Separate mixed-methods analyses of variance (ANOVAs; within-subject: condition/path; between-subject: group) were used for statistical analyses.

RESULTS

Velocity was lower when walking using a walker while completing a cognitive task (p < .001), in the figure-of-8 Walk Test (p < .001), and in older adults (p = .001). Stride time variability increased with walking path and condition difficulty (p < .001) for the straight path versus the figure-of-8 Walk Test.

CONCLUSIONS

Using a 4-wheeled walker resulted in a slower and more inconsistent gait pattern across both age groups. Walking more complex configurations resulted in the prioritization of gait over the cognitive task while performing the dual-task conditions. No evidence of an age-related difference in the effect of initial walker use on gait was observed. Nonetheless, walkers are cognitively demanding and their introduction should warrant a clinical follow-up.

The impact of walker height positions and their influence on triceps activity and energy conservation: a pilot study

Background/Aims

Millions of adults use walkers for functional mobility. Inappropriate walker use is associated with incorrect height, forward-leaning posture, and increased energy expenditure. Few studies have investigated the impact of walker positions and their influence on triceps activity. The present study assessed walker height and baseline positioning for individuals with a 50% weight bearing restriction of the lower extremity, and implications for energy conservation.

Methods

A total of 38 young adults (mean age = 24.95 years; 84.2% female; 15.8% male) participated in this study with a two-wheeled walker. Participants executed five walker positions while maintaining 50% weight bearing of the lower extremity to determine the effect on triceps electromyography activity.

Results

Triceps electromyography activity did significantly change across the five walker positions assessed (X2 [df=37, P<0.001]). This study showed that the median electromyography activity for positions B (median=0.268) and A (median=0.280) was significantly less than the median electromyography activity for position E (median=0.452; P<0.001). The effect sizes for comparisons of positions B and E (r=0.49) as well as A and E were the largest (r=0.53).

Conclusions

These findings suggest an elbow angle of 26–35° (position B), followed by an elbow angle of 15–25° (position A), with the walker in line with the heels of the participant, to be superior in minimising exertion of the triceps.