WHOM do we contact to get this tested for stroke survivors? Since no one knows, that just proves that everything in stroke is a complete failure.
Reducing the energy cost of walking in older adults using a passive hip flexion device
Abstract
Background
Elevated energy cost is a hallmark feature of gait in older adults. As such, older adults display a general avoidance of walking which contributes to declining health status and risk of morbidity. Exoskeletons offer a great potential for lowering the energy cost of walking, however their complexity and cost often limit their use. To overcome some of these issues, in the present work we propose a passive wearable assistive device, namely Exoband, that applies a torque to the hip flexors thus reducing the net metabolic power of wearers.Methods
Nine participants (age: 62.1 ± 5.6 yr; height: 1.71 ± 0.05 m; weight: 76.3 ± 11.9 kg) walked on a treadmill at a speed of 1.1 m/s with and without the Exoband. Metabolic power was measured by indirect calorimetry and spatio-temporal parameters measured using an optical measurement system. Heart rate and ratings of perceived exertion were recorded during data collection to monitor relative intensity of the walking trials.Results
The Exoband was able to provide a consistent torque (~ 0.03–0.05 Nm/kg of peak torque) to the wearers. When walking with the Exoband, participants displayed a lower net metabolic power with respect to free walking (− 3.3 ± 3.0%; p = 0.02). There were no differences in spatio-temporal parameters or relative intensities when walking with or without the Exoband.Conclusions
This study demonstrated that it is possible to reduce metabolic power during walking in older adults with the assistance of a passive device that applies a torque to the hip joint. Wearable, lightweight and low-cost devices such as the Exoband have the potential to make walking less metabolically demanding for older individuals.Background
The
reduction in walking function experienced by older adults impacts
quality of life, health status, and predicts life expectancy. As adults
age, difficulty walking affects relative independence and the ability to
execute daily tasks in an autonomous way [1],
also representing a major burden to their health status and risk of
morbidity. As a consequence, reduced walking in older adults is a major
contributing factor to a variety of medical issues such as high blood
pressure, obesity, and more severe conditions such as cardiovascular
diseases and diabetes [2,3,4].
Elevated energy cost is a hallmark feature of gait in older adults and is most likely caused by multiple factors, including changes in neuromuscular and gait mechanics [5]. Elevated walking energy costs have also been shown to result in a general avoidance of walking and other activities in older adults [6]. Activity avoidance increases morbidity and mortality risk [7]. As such, lowering walking energy cost in older adults is predicted to significantly improve health, quality of life and life expectancy in older adults.
Recent engineering advancements coupled with musculoskeletal research have resulted in novel solutions to assist human walking. Exoskeletons offer great potential for lowering the energy cost of walking, reducing fatigue and mitigating mechanical stress on joints and bones [8,9,10,11,12]. Yet despite significant advancements in this field, exoskeletons that reduce metabolic cost of walking still present several shortcomings and are not widely adopted by consumers. Current devices are heavy, cumbersome to wear, and require trained personnel to be operated and maintained [13, 14]. They are also powered by large batteries that drain quickly and these, together with the electronic components needed to implement different control architectures, can be very costly. To overcome some of these limitations, recent studies have shown the potential of passive exoskeletons (devices that do not include motors and batteries) to assist walking [8] and running [15, 16]. These studies highlighted that, despite years of human evolution, it is possible to reduce the metabolic cost of gait by means of passive devices that store and release mechanical energy generated by the body during specific phases of the gait cycle.
Building on the foundation of this previous work, this manuscript presents a passive hip device composed of textile, thus making it extremely lightweight and easy to wear. The aim of this study is to determine whether a simple device that assists hip flexion can reduce the metabolic cost of walking in older adults. The choice to design a device helping hip flexion in the elderly was decided for two main reasons. The first is that it has been established previously that aging causes an increased reliance on the hip rather than on the ankle to power walking [17, 18]; the second is that a relevant simulation study on powered exoskeletons [19] indicated that assisting hip flexion provides greater metabolic savings with respect to other joints. Research in the exoskeleton field has also highlighted that physiological and neurological differences between individuals can cause divergent metabolic responses to the same device [20,21,22], and that responses can change considerably during the course of adaptation [23, 24], thus underlining the importance of an individualized level of assistance applied by the device [25, 26]. As such, we evaluated three different levels of assistance associated with a specific force index: LOW (0.3 N/kg), MED (0.5 N/kg) and HIGH (0.7 N/kg) applied by our device in a group of healthy community dwelling older adults.
Elevated energy cost is a hallmark feature of gait in older adults and is most likely caused by multiple factors, including changes in neuromuscular and gait mechanics [5]. Elevated walking energy costs have also been shown to result in a general avoidance of walking and other activities in older adults [6]. Activity avoidance increases morbidity and mortality risk [7]. As such, lowering walking energy cost in older adults is predicted to significantly improve health, quality of life and life expectancy in older adults.
Recent engineering advancements coupled with musculoskeletal research have resulted in novel solutions to assist human walking. Exoskeletons offer great potential for lowering the energy cost of walking, reducing fatigue and mitigating mechanical stress on joints and bones [8,9,10,11,12]. Yet despite significant advancements in this field, exoskeletons that reduce metabolic cost of walking still present several shortcomings and are not widely adopted by consumers. Current devices are heavy, cumbersome to wear, and require trained personnel to be operated and maintained [13, 14]. They are also powered by large batteries that drain quickly and these, together with the electronic components needed to implement different control architectures, can be very costly. To overcome some of these limitations, recent studies have shown the potential of passive exoskeletons (devices that do not include motors and batteries) to assist walking [8] and running [15, 16]. These studies highlighted that, despite years of human evolution, it is possible to reduce the metabolic cost of gait by means of passive devices that store and release mechanical energy generated by the body during specific phases of the gait cycle.
Building on the foundation of this previous work, this manuscript presents a passive hip device composed of textile, thus making it extremely lightweight and easy to wear. The aim of this study is to determine whether a simple device that assists hip flexion can reduce the metabolic cost of walking in older adults. The choice to design a device helping hip flexion in the elderly was decided for two main reasons. The first is that it has been established previously that aging causes an increased reliance on the hip rather than on the ankle to power walking [17, 18]; the second is that a relevant simulation study on powered exoskeletons [19] indicated that assisting hip flexion provides greater metabolic savings with respect to other joints. Research in the exoskeleton field has also highlighted that physiological and neurological differences between individuals can cause divergent metabolic responses to the same device [20,21,22], and that responses can change considerably during the course of adaptation [23, 24], thus underlining the importance of an individualized level of assistance applied by the device [25, 26]. As such, we evaluated three different levels of assistance associated with a specific force index: LOW (0.3 N/kg), MED (0.5 N/kg) and HIGH (0.7 N/kg) applied by our device in a group of healthy community dwelling older adults.
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