Step time asymmetry but not step length asymmetry is adapted to optimize energy cost of split‐belt treadmill walking

The metabolic cost of walking in healthy individuals increases with spatiotemporal gait asymmetries. Pathological gait, such as post-stroke, often has asymmetry in step lengths and step times which may contribute to an increased energy cost. But paradoxically, enforcing step length symmetry does not reduce metabolic cost of post-stroke walking. The isolated and interacting costs of asymmetry in step times and step lengths remain unclear, because previous studies did not simultaneously enforce spatial and temporal gait asymmetries. Here, we delineate isolated costs of asymmetry in step times and step lengths in healthy human walking. We first show that the cost of step length asymmetry is predicted by the cost of taking two non-preferred step lengths (one short and one long), but that step time asymmetry adds an extra cost beyond the cost of non-preferred step times. The metabolic power of step time asymmetry is about 2.5 times greater than the cost of step length asymmetry. Furthermore, the costs are not additive when walking with asymmetric step times and step lengths: metabolic power of concurrent asymmetry in step lengths and step times is driven by the cost of step time asymmetry alone. The metabolic power of asymmetry is explained by positive mechanical power produced during single support phases to compensate for a net loss of center of mass power incurred during double support phases. These data may explain why metabolic cost remains invariant to step length asymmetry in post-stroke walking and suggests how effects of asymmetry on energy cost can be attenuated.

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A Comparison of Treadmill and Overground Walking Effects on Step Cycle Asymmetry in Young and Older Individuals

Journal of Applied Biomechanics ◽

10.1123/jab.29.2.188 ◽

2013 ◽

Vol 29 (2) ◽

pp. 188-193 ◽

Cited By ~ 21

Author(s):

Hanatsu Nagano ◽

Rezaul K. Begg ◽

William A. Sparrow ◽

Simon Taylor

Keyword(s):

Older Adults ◽

Walking Speed ◽

Step Length ◽

Treadmill Walking ◽

Older Individuals ◽

Aging Effects ◽

Overground Walking ◽

Time Data ◽

Step Cycle ◽

Step Velocity

Although lower limb strength becomes asymmetrical with age, past studies of aging effects on gait biomechanics have usually analyzed only one limb. This experiment measured how aging and treadmill surface influenced both dominant and nondominant step parameters in older (mean 74.0 y) and young participants (mean 21.9 y). Step-cycle parameters were obtained from 3-dimensional position/time data during preferred-speed walking for 40 trials along a 10 m walkway and for 10 minutes of treadmill walking. Walking speed (young 1.23 m/s, older 1.24 m/s) and step velocity for the two age groups were similar in overground walking but older adults showed significantly slower walking speed (young 1.26 m/s, older 1.05 m/s) and step velocity on the treadmill due to reduced step length and prolonged step time. Older adults had shorter step length than young adults and both groups reduced step length on the treadmill. Step velocity and length of older adults’ dominant limb was asymmetrically larger. Older adults increased the proportion of double support in step time when treadmill walking. This adaptation combined with reduced step velocity and length may preserve balance. The results suggest that bilateral analyses should be employed to accurately describe asymmetric features of gait especially for older adults.

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Age effects on step adaptation during treadmill walking with continuous step length biofeedback

Gait & Posture ◽

10.1016/j.gaitpost.2020.04.027 ◽

2020 ◽

Vol 80 ◽

pp. 174-177

Author(s):

Mahboobeh Mehdikhani ◽

Simon Taylor ◽

Blynn L. Shideler ◽

Rajna Ogrin ◽

Rezaul Begg

Keyword(s):

Step Length ◽

Treadmill Walking ◽

Age Effects

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Feasibility of Using Foot–Ground Clearance Biofeedback Training in Treadmill Walking for Post-Stroke Gait Rehabilitation

Brain Sciences ◽

10.3390/brainsci10120978 ◽

2020 ◽

Vol 10 (12) ◽

pp. 978

Author(s):

Hanatsu Nagano ◽

Catherine M. Said ◽

Lisa James ◽

Rezaul K. Begg

Keyword(s):

Real Time ◽

Training Session ◽

Step Length ◽

Gait Training ◽

Treadmill Walking ◽

Biofeedback Training ◽

Step Width ◽

Double Support ◽

Post Stroke ◽

Foot Clearance

Hemiplegic stroke often impairs gait and increases falls risk during rehabilitation. Tripping is the leading cause of falls, but the risk can be reduced by increasing vertical swing foot clearance, particularly at the mid-swing phase event, minimum foot clearance (MFC). Based on previous reports, real-time biofeedback training may increase MFC. Six post-stroke individuals undertook eight biofeedback training sessions over a month, in which an infrared marker attached to the front part of the shoe was tracked in real-time, showing vertical swing foot motion on a monitor installed in front of the subject during treadmill walking. A target increased MFC range was determined, and participants were instructed to control their MFC within the safe range. Gait assessment was conducted three times: Baseline, Post-training and one month from the final biofeedback training session. In addition to MFC, step length, step width, double support time and foot contact angle were measured. After biofeedback training, increased MFC with a trend of reduced step-to-step variability was observed. Correlation analysis revealed that MFC height of the unaffected limb had interlinks with step length and ankle angle. In contrast, for the affected limb, step width variability and MFC height were positively correlated. The current pilot-study suggested that biofeedback gait training may reduce tripping falls for post-stroke individuals.

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Learning the spatial features of a locomotor task is slowed after stroke

Journal of Neurophysiology ◽

10.1152/jn.00486.2013 ◽

2014 ◽

Vol 112 (2) ◽

pp. 480-489 ◽

Cited By ~ 19

Author(s):

Christine M. Tyrell ◽

Erin Helm ◽

Darcy S. Reisman

Keyword(s):

Motor Learning ◽

Spatial Pattern ◽

Retention Test ◽

Step Length ◽

Treadmill Walking ◽

Neurological Dysfunction ◽

Stroke Survivors ◽

Spatial Features ◽

Walking Pattern ◽

Neurologically Intact

The capacity for humans to learn a new walking pattern has been explored with a split-belt treadmill during single sessions of adaptation, but the split-belt treadmill can also be used to study longer-term motor learning. Although the literature provides some information about motor learning after stroke, existing studies have primarily involved the upper extremity and the results are mixed. The purpose of this study was to characterize learning of a novel locomotor task in stroke survivors. We hypothesized that the presence of neurological dysfunction from stroke would result in slower learning of a locomotor task and decreased retention of what was learned and that these deficits would be related to level of sensorimotor impairment. Sixteen participants with stroke and sixteen neurologically intact participants walked on a split-belt treadmill for 15 min on 5 consecutive days and during a retention test. Step length and limb phase were measured to capture learning of the spatial and temporal aspects of walking. Learning the spatial pattern of split-belt treadmill walking was slowed after stroke compared with neurologically intact subjects, whereas there were no differences between these two groups in learning the temporal pattern. During the retention test, poststroke participants demonstrated equal retention of the split-belt treadmill walking pattern compared with those who were neurologically intact. The results suggest that although stroke survivors are slower to learn a new spatial pattern of gait, if given sufficient time they are able to do so to the same extent as those who are neurologically intact.

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Contributions of spatial and temporal control of step length symmetry in the transfer of locomotor adaptation from a motorized to a non-motorized split-belt treadmill

10.1101/699736 ◽

2019 ◽

Author(s):

Daniel L. Gregory ◽

Frank C. Sup ◽

Julia T. Choi

Keyword(s):

Repeated Measures ◽

Step Length ◽

Treadmill Walking ◽

The Body ◽

Speed Ratio ◽

Temporal Control ◽

After Effects ◽

Locomotor Adaptation ◽

Length Difference ◽

Motor Outputs

AbstractBackgroundLocomotor adaptation during motorized split-belt walking depends on independent processes for spatial and temporal control of step length symmetry. The unique mechanics of motorized split-belt walking that constrains two limbs to move at different speeds during double support may limit transfer of step length adaptations to new walking contexts.Research questionHow do spatial and temporal locomotor outputs contribute to transfer of step length adaptation from constrained motorized split-belt walking to unconstrained non-motorized split-belt walking?MethodsWe built a non-motorized split-belt treadmill that allows the user to walk at their own pace while simultaneously allowing the two belts to be self-propelled at different speeds. 10 healthy young participants walked on the non-motorized split-belt treadmill after an initial 10-minute adaptation on the motorized split-belt with a 2:1 speed ratio. Foot placement relative to the body and timing between heel strikes were calculated to determine spatial and temporal motor outputs, respectively. Separate repeated measures ANOVAs were used for step length difference and its spatial and temporal components to assess for transfer to the non-motorized treadmill.ResultsWe found robust after-effects in step length difference during transfer to non-motorized split-belt treadmill walking that were primarily driven by changes in temporal motor outputs. Conversely, residual after-effects observed during motorized tied-belt treadmill walking (post-transfer) were driven by changes in spatial motor outputs.SignificanceOur data showed decoupling of adapted spatial and temporal locomotor outputs during the transfer to non-motorized split-belt walking, raising the new possibility of using a non-motorized split-belt treadmill to target specific spatial or temporal gait deficits.

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Gait characteristics in individuals with Parkinson’s disease during 1-minute treadmill walking

PeerJ ◽

10.7717/peerj.9463 ◽

2020 ◽

Vol 8 ◽

pp. e9463

Author(s):

Byungjoo Noh ◽

Changhong Youm ◽

Myeounggon Lee ◽

Sang-Myung Cheon

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Gait Speed ◽

Step Length ◽

Treadmill Walking ◽

Measurement Unit ◽

Gait Characteristics ◽

Age Related ◽

Axial Acceleration ◽

Spatiotemporal Parameters

Background No previous study has examined the age-dependent characteristics of gait in individuals between 50 and 79 years simultaneously in healthy individuals and individuals with Parkinson’s disease (PD) over continuous gait cycles. This study aimed to investigate age-related differences in gait characteristics on individuals age ranged 50–79 years, including individuals with PD, during a 1-minute treadmill walking session. Additionally, we aimed to investigate the differences associated with spatiotemporal gait parameters and PD compared in age-matched individuals. Methods This study included 26 individuals with PD and 90 participants age ranged 50–79 years. The treadmill walking test at a self-preferred speed was performed for 1 min. The embedded inertial measurement unit sensor in the left and right outsoles-based system was used to collect gait characteristics based on tri-axial acceleration and tri-axial angular velocities. Results Participants aged >60 years had a decreased gait speed and shortened stride and step, which may demonstrate a distinct shift in aging (all p < 0.005). Individuals with PD showed more of a decrease in variables with a loss of consistency, including gait asymmetry (GA), phase coordination index (PCI) and coefficient of variation (CV) of all variables, than age-matched individuals (all p < 0.001). Gait speed, stride and step length, stance phase, variability, GA and PCI were the variables that highly depended on age and PD. Discussion Older adults could be considered those older than 60 years of age when gait alterations begin, such as a decreased gait speed as well as shortened stride and step length. On the other hand, a loss of consistency in spatiotemporal parameters and a higher GA and PCI could be used to identify individuals with PD. Thus, the CV of all spatiotemporal parameters, GA and PCI during walking could play an important role and be useful in identifying individuals with PD. Conclusion This study provided the notable aging pattern characteristics of gait in individuals >50 years, including individuals with PD. Increasing age after 60 years is associated with deterioration in spatiotemporal parameters of gait during continuous 1-minute treadmill walking. Additionally, GA, PCI and the CV of all variables could be used to identify PD which would be placed after 70 years of age. It may be useful to determine the decline of gait performance in general and among individuals with PD.

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Correlation between cardiopulmonary metabolic energy cost and lower-limb muscle activity during inclined treadmill gait in older adults

BMC Geriatrics ◽

10.1186/s12877-021-02401-9 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Jihye Kim ◽

Hwang-Jae Lee ◽

Su-Hyun Lee ◽

Jungsoo Lee ◽

Won Hyuk Chang ◽

...

Keyword(s):

Older Adults ◽

Lower Limb ◽

Muscle Activity ◽

Energy Cost ◽

Stance Phase ◽

Treadmill Walking ◽

Metabolic Energy ◽

Lower Limb Muscle ◽

Limb Muscle ◽

Increased Activity

Abstract Background Inclined walking requires more cardiopulmonary metabolic energy and muscle strength than flat-level walking. This study sought to investigate changes in lower-limb muscle activity and cardiopulmonary metabolic energy cost during treadmill walking with different inclination grades and to discern any correlation between these two measures in older adults. Methods Twenty-four healthy older adults (n = 11 males; mean age: 75.3 ± 4.0 years) participated. All participants walked on a treadmill that was randomly inclined at 0% (condition 1), 10% (condition 2), and 16% (condition 3) for five minutes each. Simultaneous measurements of lower-limb muscle activity and cardiopulmonary metabolic energy cost during inclined treadmill walking were collected. Measured muscles included the rectus abdominis (RA), erector spinae (ES), rectus femoris (RF), biceps femoris (BF), vastus medialis (VM), tibialis anterior (TA), medial head of the gastrocnemius (GCM), and soleus (SOL) muscles on the right side. Results As compared with 0% inclined treadmill gait, the 10% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 22.9%, while the 16% inclined treadmill gait increased the net cardiopulmonary metabolic energy cost by 44.2%. In the stance phase, as the slope increased, activity was significantly increased in the RA, RF, VM, BF, GCM, and SOL muscles. In the swing phase, As the slope increased activity was significantly increased in the RA, RF, VM, BF, and TA muscles. SOL muscle activity was most relevant to the change in cardiopulmonary metabolic energy cost in the stance phase of inclined treadmill walking. The relationship between the increase in cardiopulmonary metabolic energy cost and changes in muscle activity was also significant in the VM, GCM, and RF. Conclusion This study demonstrated that changes in SOL, VM, GCM, and RA muscle activity had a significant relationship with cardiopulmonary metabolic energy cost increment during inclined treadmill walking. These results can be used as basic data for various gait-training programs and as an indicator in the development of assistive algorithms of wearable walking robots for older adults. Trial registration Clinical trials registration information: ClinicalTrials.gov Identifier: NCT04614857 (05/11/2020).

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Use-dependent plasticity explains aftereffects in visually guided locomotor learning of a novel step length asymmetry

Journal of Neurophysiology ◽

10.1152/jn.00083.2020 ◽

2020 ◽

Vol 124 (1) ◽

pp. 32-39 ◽

Cited By ~ 1

Author(s):

Jonathan M. Wood ◽

Hyosub E. Kim ◽

Margaret A. French ◽

Darcy S. Reisman ◽

Susanne M. Morton

Keyword(s):

Upper Extremity ◽

Significant Role ◽

Step Length ◽

Treadmill Walking ◽

Prediction Errors ◽

Visually Guided ◽

Important Process ◽

Dependent Plasticity ◽

Sensory Prediction ◽

Dose Dependent

Use-dependent plasticity, or learning from repetition, is an important process for upper extremity reaching tasks, but its contribution to walking is not well established. Here, we demonstrate the existence of a dose-dependent, use-dependent process during visually guided treadmill walking. We also show that sensory prediction errors, previously thought to drive aftereffects in similar locomotor learning paradigms, do not appear to play a significant role in visually driven learning of a novel step asymmetry during treadmill walking.

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Error-augmentation gait training to improve gait symmetry in patients with non-traumatic lower limb amputation: A proof-of-concept study

Prosthetics and Orthotics International ◽

10.1177/0309364619843777 ◽

2019 ◽

Vol 43 (4) ◽

pp. 426-433

Author(s):

Paul W Kline ◽

Amanda M Murray ◽

Matthew J Miller ◽

Thomas Fields ◽

Cory L Christiansen

Keyword(s):

Step Length ◽

Gait Training ◽

Limb Amputation ◽

Single Session ◽

Overground Walking ◽

Transtibial Amputation ◽

Time Asymmetry ◽

Gait Symmetry ◽

Stance Time ◽

Training Protocol

Background:Asymmetrical stepping patterns are chronic gait impairment for individuals with non-traumatic lower limb amputation. Persistent gait asymmetries contribute to poor gait efficiency, decreased physical function, and development of secondary orthopedic conditions.Objectives:Evaluate the feasibility and preliminary responsiveness of a treadmill-based, error-augmentation gait training protocol to improve gait symmetry in patients with non-traumatic transtibial amputation.Study design:Single group, pre- and post-test.Methods:The error-augmentation gait training protocol involved walking on a split-belt treadmill with asymmetrical belt speeds for five 3-min sets. Spatiotemporal gait characteristics during overground walking at self-selected and fast walking speeds were assessed prior to, immediately after, and 20 min following the error-augmentation gait training protocol. Outcomes included practicality, implementation feasibility, safety, participant acceptability, and change in gait asymmetry.Results:All four participants completed the error-augmentation gait training protocol as prescribed, without adverse events, and found the intervention to be acceptable. Step length and stance time asymmetry during overground walking changed immediately following the error-augmentation gait training protocol with inconsistent changes retained after a 20 min washout period.Conclusions:A single session of error-augmentation gait training is a feasible and safe intervention to modify gait asymmetry in patients with non-traumatic transtibial amputation. Additional study with larger sample sizes and repeated error-augmentation gait training dosing are warranted.Clinical relevanceGait training using error-augmentation on a split-belt treadmill may modify step length and stance time asymmetry for patients with non-traumatic transtibial amputation, but additional research is needed regarding short- and long-term efficacy. Additional training sessions may be needed to sustain initial changes achieved from a single session.

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