Reducing Circumduction and Hip Hiking During Hemiparetic Walking Through Targeted Assistance of the Paretic Limb Using a Soft Robotic Exosuit

Awad, Louis N.; Bae, Jaehyun; Kudzia, Pawel; Long, Andrew; Hendron, Kathryn; Holt, Kenneth G.; O’Donnell, Kathleen; Ellis, Terry; Walsh, Conor J.

doi:10.1097/phm.0000000000000800

Cited by 57 publications

(52 citation statements)

References 28 publications

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“…This finding may be explained by prior work by Zelik and colleagues that demonstrated the importance of accounting for peripheral power, foot power and 3DoF joint translation power in addition to the traditionally evaluated 3DoF joint rotational power (Zelik and Kuo, 2010;Zelik et al, 2015). Although validation of this hypothesis is beyond the scope of this study, in our prior work, we observed exosuit-induced reductions in limb circumduction and hip hiking (Awad et al, 2017b). Such changes in foot and pelvis trajectories relative to the COM suggest a substantial reduction in peripheral power.…”

Section: Discussionmentioning

confidence: 46%

“…team has recently shown exosuit-induced reductions in whole-limb compensatory gait motions that are known to increase metabolic power (Shorter et al, 2017), such as circumduction and hip hiking (Awad et al, 2017b). Further study into the potential mediating role that exosuit-induced reductions in compensatory walking strategies plays in the relationship between changes in ankle power and metabolic power would enhance our understanding of how active assistance delivered through a wearable robot can improve walking after stroke.…”

Section: Discussionmentioning

confidence: 99%

“…In previous work, we demonstrated that a laboratorybased exosuit testbed consisting of an off-board actuator and two textile modules that independently assisted paretic ankle PF and DF during walking (Awad et al, 2017a;Bae et al, 2015) (Fig. 1) could reduce compensatory gait patterns such as hip hiking and circumduction (Awad et al, 2017b), facilitate more symmetric forward propulsive force generation by the paretic and non-paretic limbs, and reduce the metabolic cost of walking (Awad et al, 2017a). Although this previous work demonstrates the substantial impact that exosuits can have on walking after stroke, propulsion symmetry and the metabolic cost of walking are composite variables that can be altered through a variety of biomechanical mechanisms.…”

Section: Introductionmentioning

confidence: 94%

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Biomechanical mechanisms underlying exosuit-induced improvements in walking economy after stroke

Bae

Awad

Long

et al. 2018

Journal of Experimental Biology

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Stroke-induced hemiparetic gait is characteristically asymmetric and metabolically expensive. Weakness and impaired control of the paretic ankle contribute to reduced forward propulsion and ground clearance - walking subtasks critical for safe and efficient locomotion. Targeted gait interventions that improve paretic ankle function after stroke are therefore warranted. We have developed textile-based, soft wearable robots that transmit mechanical power generated by off-board or body-worn actuators to the paretic ankle using Bowden cables (soft exosuits) and have demonstrated the exosuits can overcome deficits in paretic limb forward propulsion and ground clearance, ultimately reducing the metabolic cost of hemiparetic walking. This study elucidates the biomechanical mechanisms underlying exosuit-induced reductions in metabolic power. We evaluated the relationships between exosuit-induced changes in the body center of mass (COM) power generated by each limb, individual joint power and metabolic power. Compared with walking with an exosuit unpowered, exosuit assistance produced more symmetrical COM power generation during the critical period of the step-to-step transition (22.4±6.4% more symmetric). Changes in individual limb COM power were related to changes in paretic (=0.83, 0.004) and non-paretic (0.73, 0.014) ankle power. Interestingly, despite the exosuit providing direct assistance to only the paretic limb, changes in metabolic power were related to changes in non-paretic limb COM power (=0.80, 0.007), not paretic limb COM power (0.05). These findings contribute to a fundamental understanding of how individuals post-stroke interact with an exosuit to reduce the metabolic cost of hemiparetic walking.

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Section: Discussionmentioning

confidence: 46%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 94%

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Biomechanical mechanisms underlying exosuit-induced improvements in walking economy after stroke

Bae

Awad

Long

et al. 2018

Journal of Experimental Biology

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“…Similar to [38], we quantified hip circumduction as the medio-lateral range of motion of the prosthetic ankle marker coordinates during a stride. This method corresponds better with what a clinician observes visually than other measures such as hip frontal-plane range of motion [39].…”

Section: Data and Statistical Analysesmentioning

confidence: 99%

A Phase Variable Approach for Improved Rhythmic and Non-Rhythmic Control of a Powered Knee-Ankle Prosthesis

et al. 2019

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Although there has been recent progress in control of multi-joint prosthetic legs for rhythmic tasks such as walking, control of these systems for non-rhythmic motions and general real-world maneuvers is still an open problem. In this article, we develop a new controller that is capable of both rhythmic (constant-speed) walking, transitions between speeds and/or tasks, and some common volitional leg motions. We introduce a new piecewise holonomic phase variable, which, through a finite state machine, forms the basis of our controller. The phase variable is constructed by measuring the thigh angle, and the transitions in the finite state machine are formulated through sensing foot contact along with attributes of a nominal reference gait trajectory. The controller was implemented on a powered knee-ankle prosthesis and tested with a transfemoral amputee subject, who successfully performed a wide range of rhythmic and non-rhythmic tasks, including slow and fast walking, quick start and stop, backward walking, walking over obstacles, and kicking a soccer ball. Use of the powered leg resulted in clinically significant reductions in amputee compensations for rhythmic tasks (including vaulting and hip circumduction) when compared to use of the take-home passive leg. In addition, considerable improvements were also observed in the performance for nonrhythmic tasks. The proposed approach is expected to provide a better understanding of rhythmic and non-rhythmic motions in a unified framework, which in turn can lead to more reliable control of multi-joint prostheses for a wider range of real-world tasks.

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“…As previously described 3 , mechanical power generated by actuators are transmitted to the wearer's paretic ankle during walking via the interaction of cable-based transmissions and the exosuit's functional textiles. In previous studies, we demonstrated that exosuits can actively assist the paretic limb during walking and improve ground clearance, increase propulsion symmetry, and reduce the metabolic burden of hemiparetic gait after stroke 4,5 . The present study extends this work and evaluates the effects of a portable exosuit on short-and long-distance walking function.…”

mentioning

confidence: 99%

Soft exosuits increase walking speed and distance after stroke

Awad¹,

Bae²,

O’Donnell³

et al. 2017

2017 International Symposium on Wearable Robotics and Rehabilitation (WeRob)

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Background & Purpose : Portable exoskeletons are the state of the art in wearable robotics 1 . These remarkable machines have enabled individuals who are unable to walk, to walk again. However, for those that retain the ability to walk following neurological injury, such as the majority poststroke, rigid systems may not be necessary to restore more normal walking behavior 2 . Our group has developed soft wearable robots (exosuits) made from garment-like, functional textiles. As previously described 3 , mechanical power generated by actuators are transmitted to the wearer's paretic ankle during walking via the interaction of cable-based transmissions and the exosuit's functional textiles. In previous studies, we demonstrated that exosuits can actively assist the paretic limb during walking and improve ground clearance, increase propulsion symmetry, and reduce the metabolic burden of hemiparetic gait after stroke 4,5 . The present study extends this work and evaluates the effects of a portable exosuit on short-and long-distance walking function.

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Reducing Circumduction and Hip Hiking During Hemiparetic Walking Through Targeted Assistance of the Paretic Limb Using a Soft Robotic Exosuit

Cited by 57 publications

References 28 publications

Biomechanical mechanisms underlying exosuit-induced improvements in walking economy after stroke

Biomechanical mechanisms underlying exosuit-induced improvements in walking economy after stroke

A Phase Variable Approach for Improved Rhythmic and Non-Rhythmic Control of a Powered Knee-Ankle Prosthesis

Soft exosuits increase walking speed and distance after stroke

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