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Smith RE, Shelton AD, Sawicki GS, Franz JR. The effects of plantarflexor weakness and reduced tendon stiffness with aging on gait stability. PLoS One 2024; 19:e0302021. [PMID: 38625839 PMCID: PMC11020829 DOI: 10.1371/journal.pone.0302021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 03/26/2024] [Indexed: 04/18/2024] Open
Abstract
Falls among older adults are a costly public health concern. Such falls can be precipitated by balance disturbances, after which a recovery strategy requiring rapid, high force outputs is necessary. Sarcopenia among older adults likely diminishes their ability to produce the forces necessary to arrest gait instability. Age-related changes to tendon stiffness may also delay muscle stretch and afferent feedback and decrease force transmission, worsening fall outcomes. However, the association between muscle strength, tendon stiffness, and gait instability is not well established. Given the ankle's proximity to the onset of many walking balance disturbances, we examined the relation between both plantarflexor strength and Achilles tendon stiffness with walking-related instability during perturbed gait in older and younger adults-the latter quantified herein using margins of stability and whole-body angular momentum including the application of treadmill-induced slip perturbations. Older and younger adults did not differ in plantarflexor strength, but Achilles tendon stiffness was lower in older adults. Among older adults, plantarflexor weakness associated with greater whole-body angular momentum following treadmill-induced slip perturbations. Weaker older adults also appeared to walk and recover from treadmill-induced slip perturbations with more caution. This study highlights the role of plantarflexor strength and Achilles tendon stiffness in regulating lateral gait stability in older adults, which may be targets for training protocols seeking to minimize fall risk and injury severity.
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Affiliation(s)
- Ross E. Smith
- Joint Dept. of Biomedical Engineering, UNC Chapel Hill and NC State University, Chapel Hill, North Carolina, United States of America
| | - Andrew D. Shelton
- Joint Dept. of Biomedical Engineering, UNC Chapel Hill and NC State University, Chapel Hill, North Carolina, United States of America
| | - Gregory S. Sawicki
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Jason R. Franz
- Joint Dept. of Biomedical Engineering, UNC Chapel Hill and NC State University, Chapel Hill, North Carolina, United States of America
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Differences in motor response to stability perturbations limit fall-resisting skill transfer. Sci Rep 2022; 12:21901. [PMID: 36535994 PMCID: PMC9763399 DOI: 10.1038/s41598-022-26474-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
This study investigated transfer of improvements in stability recovery performance to novel perturbations. Thirty adults (20-53 yr) were assigned equally to three treadmill walking groups: groups exposed to eight trip perturbations of either low or high magnitude and a third control group that walked unperturbed. Following treadmill walking, participants were exposed to stability loss from a forward-inclined position (lean-and-release) and an overground trip. Lower limb joint kinematics for the swing phase of recovery steps was compared for the three tasks using statistical parametric mapping and recovery performance was analysed by margin of stability and base of support. The perturbation groups improved stability (greater margin of stability) over the eight gait perturbations. There was no group effect for stability recovery in lean-and-release. For the overground trip, both perturbation groups showed similar enhanced stability recovery (margin of stability and base of support) compared to controls. Differences in joint angle kinematics between treadmill-perturbation and lean-and-release were more prolonged and greater than between the two gait perturbation tasks. This study indicates that: (i) practising stability control enhances human resilience to novel perturbations; (ii) enhancement is not necessarily dependent on perturbation magnitude; (iii) differences in motor response patterns between tasks may limit transfer.
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McCrum C, Bhatt TS, Gerards MHG, Karamanidis K, Rogers MW, Lord SR, Okubo Y. Perturbation-based balance training: Principles, mechanisms and implementation in clinical practice. Front Sports Act Living 2022; 4:1015394. [PMID: 36275443 PMCID: PMC9583884 DOI: 10.3389/fspor.2022.1015394] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 09/20/2022] [Indexed: 02/05/2023] Open
Abstract
Since the mid-2000s, perturbation-based balance training has been gaining interest as an efficient and effective way to prevent falls in older adults. It has been suggested that this task-specific training approach may present a paradigm shift in fall prevention. In this review, we discuss key concepts and common issues and questions regarding perturbation-based balance training. In doing so, we aim to provide a comprehensive synthesis of the current evidence on the mechanisms, feasibility and efficacy of perturbation-based balance training for researchers and practitioners. We address this in two sections: "Principles and Mechanisms" and "Implementation in Practice." In the first section, definitions, task-specificity, adaptation and retention mechanisms and the dose-response relationship are discussed. In the second section, issues related to safety, anxiety, evidence in clinical populations (e.g., Parkinson's disease, stroke), technology and training devices are discussed. Perturbation-based balance training is a promising approach to fall prevention. However, several fundamental and applied aspects of the approach need to be further investigated before it can be widely implemented in clinical practice.
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Affiliation(s)
- Christopher McCrum
- Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, Netherlands
- Neuromotor Rehabilitation Research Group, Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | - Tanvi S. Bhatt
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois, Chicago, IL, United States
| | - Marissa H. G. Gerards
- Department of Epidemiology, Care and Public Health Institute (CAPHRI), Maastricht University, Maastricht, Netherlands
- Department of Physiotherapy, Maastricht University Medical Center (MUMC+), Maastricht, Netherlands
| | - Kiros Karamanidis
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - Mark W. Rogers
- Department of Physical Therapy and Rehabilitation Science, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Stephen R. Lord
- Falls, Balance and Injury Research Centre, Neuroscience Research Australia, Sydney, NSW, Australia
- Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Yoshiro Okubo
- Falls, Balance and Injury Research Centre, Neuroscience Research Australia, Sydney, NSW, Australia
- Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
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Batcir S, Shani G, Shapiro A, Melzer I. Characteristics of step responses following varying magnitudes of unexpected lateral perturbations during standing among older people - a cross-sectional laboratory-based study. BMC Geriatr 2022; 22:400. [PMID: 35524172 PMCID: PMC9078012 DOI: 10.1186/s12877-022-03080-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 04/20/2022] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION The inability to recover from unexpected lateral loss of balance may be particularly relevant to the problem of falling. AIM We aimed to explore whether different kinematic patterns and strategies occur in the first recovery step in single-step trials in which a single step was required to recover from a fall, and in multiple-step trials in which more than one step was required to recover from a fall. In addition, in the multiple-step trials, we examined kinematic patterns of balance recovery where extra steps were needed to recover balance. METHODS Eighty-four older adults (79.3 ± 5.2 years) were exposed to unannounced right/left perturbations in standing that were gradually increased to trigger a recovery stepping response. We performed a kinematic analysis of the first recovery step of all single-step and multiple-step trials for each participant and of total balance recovery in the multiple-step trial. RESULTS Kinematic patterns and strategies of the first recovery step in the single-step trials were significantly dependent on the perturbation magnitude. It took a small, yet significantly longer time to initiate a recovery step and a significantly longer time to complete the recovery step as the magnitude increased. However, the first recovery step in the multiple-step trials showed no significant differences between different perturbation magnitudes; while, in total balance recovery of these trials, we observed a small, yet significant difference as the magnitude increased. CONCLUSIONS At relatively low perturbation magnitudes, i.e., single-step trials, older adults selected different first stepping strategies and kinematics as perturbation magnitudes increased, suggesting that this population activated pre-planned programs based on the perturbation magnitude. However, in the first recovery step of the multiple-step trials, i.e., high perturbation magnitudes, similar kinematic movement patterns were used at different magnitudes, suggesting a more rigid, automatic behavior, while the extra-steps were scaled to the perturbation magnitude. This suggest that older adults activate pre-planned programs based on the magnitude of the perturbation, even before the first step is completed..
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Affiliation(s)
- Shani Batcir
- Department of Physical Therapy, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Guy Shani
- Department of Information Systems, Faculty of Engineering Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Amir Shapiro
- Department of Mechanical Engineering, Faculty of Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Itshak Melzer
- Department of Physical Therapy, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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König M, Santuz A, Epro G, Werth J, Arampatzis A, Karamanidis K. Differences in muscle synergies among recovery responses limit inter-task generalisation of stability performance. Hum Mov Sci 2022; 82:102937. [PMID: 35217390 DOI: 10.1016/j.humov.2022.102937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 01/24/2022] [Accepted: 02/13/2022] [Indexed: 11/28/2022]
Abstract
Generalisation of adaptations is key to effective stability control facing variety of postural threats during daily life activity. However, in a previous study we could demonstrate that adaptations to stability control do not necessarily transfer to an untrained motor task. Here, we examined the dynamic stability and modular organisation of motor responses to different perturbations (i.e. unpredictable gait-trip perturbations and subsequent loss of anterior stability in a lean-and-release protocol) in a group of young and middle-aged adults (n = 57; age range 19-53 years) to detect potential neuromotor factors limiting transfer of adaptations within the stability control system. We hypothesized that the motor system uses different modular organisation in recovery responses to tripping and lean-and-release, which may explain lack in positive transfer of adaptations in stability control. After eight trip-perturbations participants increased their dynamic stability during the first recovery step (p < 0.001), yet they showed no significant improvement to the untrained lean-and-release transfer task compared to controls who did not undergo the perturbation exposure (p = 0.44). Regarding the neuromuscular control of responses, lower number of synergies (3 vs. 4) was found for the lean-and-release compared to the gait-trip perturbation task, revealing profound differences in both the timing and function of the recruited muscles to match the biomechanical specificity of different perturbations. Our results provide indirect evidence that the motor system uses different modular organisation in diverse perturbation responses, what possibly inhibits inter-task generalisation of adaptations in stability control.
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Affiliation(s)
- Matthias König
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom.
| | - Alessandro Santuz
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10117 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Gaspar Epro
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom
| | - Julian Werth
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, 10117 Berlin, Germany; Berlin School of Movement Science, Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Kiros Karamanidis
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, SE1 0AA London, United Kingdom
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Debelle H, Maganaris CN, O'Brien TD. Biomechanical Mechanisms of Improved Balance Recovery to Repeated Backward Slips Simulated by Treadmill Belt Accelerations in Young and Older Adults. Front Sports Act Living 2021; 3:708929. [PMID: 34622205 PMCID: PMC8490723 DOI: 10.3389/fspor.2021.708929] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Aim: Exposure to repeated gait perturbations improves the balance of older adults (OAs) and decreases their risks of falling, but little is known about the underpinning mechanical adjustments. We aimed to quantify the changing temporo-spatial and kinetic characteristics of balance recovery following repeated backward slips to better understand the mechanical adjustments responsible for improved balance. Methods: We exposed 17 young adults (YAs) (25.2 ± 3.7 years) and 17 OAs (62.4 ± 6.6 years) to 10 backward slips simulated on an instrumented treadmill by unilateral backward belt accelerations. We measured the balance of the participants (margin of stability: MoS), balance recovery (nsteps: number of steps necessary to return to a steady gait for at least three consecutive steps), temporo-spatial (step length), and kinetics [ground reaction force (GRF) angle, lower limb joint moments] for 15 steps following each slip. The results were compared with baseline. Results: Participants in both groups improved their MoS and nsteps with repeated exposure to the slips, but no significant effect of age was detected. During the perturbed step, the GRF vector was directed more posteriorly during mid-stance and more anteriorly during push-off than baseline, which resulted in a longer step. These adjustments were maintained from the first (Slip01) to the last (Slip10) slip, and by Slip10 were correlated with better balance (MoS) on the second recovery step. During the first recovery step following Slip01, participants developed lower plantarflexor and larger knee extensor moments whilst taking a shorter step, these adjustments were correlated with poorer balance and were not maintained with repeated slips. Joint moments and step length of the first recovery step returned to normal levels by Slip10. Conclusion: Young adults and OAs improved their balance with repeated slips. The adjustments that were positively correlated with balance (changes in step length, GRF angle) were maintained whilst those that were not (changes in joint moments) were discarded. All the responses observed in Slip10 were observed in Slip01. The observed balance improvements were achieved by refining the initial strategy rather than by developing a new one. The underlying mechanics were correlated with step length of the first recovery steps, which was associated with balance and should be monitored in fall prevention interventions.
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Affiliation(s)
- Héloïse Debelle
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Constantinos N Maganaris
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Thomas D O'Brien
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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Effects of Exercise-Based Interventions on Fall Risk and Balance in Patients With Chronic Obstructive Pulmonary Disease: A SYSTEMATIC REVIEW. J Cardiopulm Rehabil Prev 2021; 40:152-163. [PMID: 32355076 DOI: 10.1097/hcr.0000000000000513] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease characterized by airflow limitation and is associated with decreased balance and increased fall risk. Since falls are related to increased mortality, interventions targeting balance and fall risk could reduce morbidity and mortality. The objective of this review was to systematically assess the effects of exercise-based interventions on fall risk and balance in patients with COPD. METHODS PubMed, Web of Science, EMBASE, and CINAHL were screened for randomized controlled trails and within-group studies evaluating effects of exercise-based interventions on fall risk or balance in patients with COPD. Data were presented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. RESULTS Fifteen studies were identified, 6 randomized controlled trails and 9 within-group studies. All interventions reported positive effects on balance outcomes. No studies reported fall risk. Taking current recommendations of balance outcome measures in patients with COPD into account, pulmonary rehabilitation combined with balance training had the highest effect size. Nine papers had concerns regarding bias, mostly due to the lack of blinding outcome assessors. CONCLUSIONS Exercise-based interventions have a positive effect on balance in patients with COPD. Pulmonary rehabilitation with balance training seems to have the most beneficial effect on balance. The effects on fall risk, as well as the long-term intervention effects remain unclear. A standardized balance assessment and research on long-term effects and fall risk are recommended.
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8
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Rasmussen CM, Hunt NH. Unconstrained slip mechanics and stepping reactions depend on slip onset timing. J Biomech 2021; 125:110572. [PMID: 34186292 PMCID: PMC8355080 DOI: 10.1016/j.jbiomech.2021.110572] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 11/29/2022]
Abstract
Slips can occur at any time during stance. Accordingly, time-dependent tangential ground reaction forces likely produce a diverse range of slipping foot mechanics when traction is lost, thus requiring flexible recovery strategies to prevent falls. However, previous research has focused on slip onset in early stance, often with experimental anteroposterior constraints on the slipping foot, despite the diversity of environmental slips and falls. This study aimed to determine the effects of slip onset time on slip direction, severity (distance and velocity), and compensatory stepping responses. Ten young adults received slipping perturbations at different times during the stance phase of walking via a wearable device that reduces available friction while allowing the slipping foot to slide freely within the horizontal plane. Slip direction, distance, and peak velocity, compensatory step direction and distance, and upper body angular momentum magnitude and plane of rotation were derived from kinematic data. All outcome measurements significantly correlated with the time of slip onset. Slip direction and the plane of rotation of angular momentum deviated widely from the sagittal plane, exhibiting laterally-directed components exceeding those in the anteroposterior direction. As slip onset occurred later in stance, slip severity decreased while compensatory steps became longer and progressed from a posterior to anterior placement. These results provide insight into critical times within stance when slips are most severe, and into the diversity of slipping mechanics caused by changes in slip onset time.
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Affiliation(s)
- Corbin M Rasmussen
- Department of Biomechanics, University of Nebraska Omaha, Omaha, NE, USA.
| | - Nathaniel H Hunt
- Department of Biomechanics, University of Nebraska Omaha, Omaha, NE, USA
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Sato S, Choi JT. Neural Control of Human Locomotor Adaptation: Lessons about Changes with Aging. Neuroscientist 2021; 28:469-484. [PMID: 34014124 DOI: 10.1177/10738584211013723] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Walking patterns are adaptable in response to different environmental demands, which requires neural input from spinal and supraspinal structures. With an increase in age, there are changes in walking adaptation and in the neural control of locomotion, but the age-related changes in the neural control of locomotor adaptation is unclear. The purpose of this narrative review is to establish a framework where the age-related changes of neural control of human locomotor adaptation can be understood in terms of reactive feedback and predictive feedforward control driven by sensory feedback during locomotion. We parse out the effects of aging on (a) reactive adaptation to split-belt walking, (b) predictive adaptation to split-belt walking, (c) reactive visuomotor adaptation, and (d) predictive visuomotor adaptation, and hypothesize that specific neural circuits are influenced differentially with age, which influence locomotor adaptation. The differences observed in the age-related changes in walking adaptation across different locomotor adaptation paradigms will be discussed in light of the age-related changes in the neural mechanisms underlying locomotion.
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Affiliation(s)
- Sumire Sato
- Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, MA, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Julia T Choi
- Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, MA, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
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10
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Weber A, Friemert D, Hartmann U, Epro G, Seeley J, Werth J, Nickel P, Karamanidis K. Obstacle avoidance training in virtual environments leads to limb-specific locomotor adaptations but not to interlimb transfer in healthy young adults. J Biomech 2021; 120:110357. [PMID: 33725521 DOI: 10.1016/j.jbiomech.2021.110357] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/29/2021] [Accepted: 02/22/2021] [Indexed: 01/10/2023]
Abstract
Obstacle avoidance is one of the skills required in coping with challenging situations encountered during walking. This study examined adaptation in gait stability and its interlimb transfer in a virtual obstacle avoidance task. Twelve young adults walked on a treadmill while wearing a virtual reality headset with their body state represented in the virtual environment. At random times, but always at foot touchdown, 50 virtual obstacles of constant size appeared 0.8 m in front of the participant requiring a step over with the right leg. Early, mid and late adaptation phases were investigated by pooling data from trials 1-3, 24-26 and 48-50. One left-leg obstacle appearing after 50 right-leg trials was used to investigate interlimb transfer. Toe clearance and the anteroposterior margin of stability (MoS) at foot touchdown were calculated for the stepping leg. Toe clearance decreased over repeated practice between early and late phases from 0.13 ± 0.05 m to 0.09 ± 0.04 m (mean ± SD, p < 0.05). MoS increased from 0.05 ± 0.02 m to 0.08 ± 0.02 m (p < 0.05) between early and late phases, with no significant differences between mid and late phases. No differences were found in toe clearance and MoS between the practiced right leg for early phase and the single trial of the left leg. Obstacle avoidance during walking in a virtual environment stimulated adaptive gait improvements that were related in a nonlinear manner to practice dose, though such gait adaptations seemed to be limited in their transferability between limbs.
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Affiliation(s)
- A Weber
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom; Department of Mathematics and Technology, University of Applied Sciences Koblenz, Remagen, Germany; Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Sankt Augustin, Germany.
| | - D Friemert
- Department of Mathematics and Technology, University of Applied Sciences Koblenz, Remagen, Germany
| | - U Hartmann
- Department of Mathematics and Technology, University of Applied Sciences Koblenz, Remagen, Germany
| | - G Epro
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - J Seeley
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - J Werth
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - P Nickel
- Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Sankt Augustin, Germany
| | - K Karamanidis
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
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11
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Debelle H, Harkness-Armstrong C, Hadwin K, Maganaris CN, O'Brien TD. Recovery From a Forward Falling Slip: Measurement of Dynamic Stability and Strength Requirements Using a Split-Belt Instrumented Treadmill. Front Sports Act Living 2020; 2:82. [PMID: 33345073 PMCID: PMC7739594 DOI: 10.3389/fspor.2020.00082] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 05/28/2020] [Indexed: 11/13/2022] Open
Abstract
Aim: Falls commonly occur from trips and slips while walking. Recovery strategies from trips and backward falling slips have been extensively studied. However, until recently, forward falling slips (FFSs) have been considered less dangerous and have been understudied. This study aimed first to create an application to realistically simulate FFSs using a split-belt instrumented treadmill and then to understand the biomechanical requirements for young adults to recover from an FFS. Methods: We developed a semi-automatic custom-made application on D-Flow that triggered FFSs by briefly and unexpectedly increasing the speed (a = 5 m·s-2) of the right belt during stance. To validate the protocol, we tested against criteria defined for an ecologically and experimentally valid FFS: unexpected occurrence of the slip, increased foot velocity, forward loss of balance during the slip and consistent perturbation timing. We evaluated the recovery strategies of 17 young adults by measuring dynamic stability, joint moments and ground reaction force (GRF) vector angles before, during and on 15 steps following the FFS. Results: The application successfully triggered FFSs, according to the criteria we defined. Participants' balance returned to normal for a minimum of three consecutive steps in 10.9 (7.0) steps. Recovery from the FFSs was characterised by larger hip flexor and knee extensor moments to support the centre of mass during the slip, and a longer first recovery step with large hip extensor moments to arrest the fall followed by large knee extensor moments to raise and advance the centre of mass into the next step (p < 0.001 compared with normal gait). Subsequent steps progressively returned to normal. Conclusion: This is the first study to experimentally simulate FFSs meeting the aforementioned criteria, and to measure their effects on the dynamic balance and kinetic parameters. The split-belt instrumented treadmill proved a promising tool to better study the mechanisms of falls and recovery. The required large hip and knee joint moments generally agree with findings on trips and backward falling slips and provide an indication of the functional capacities that should be targeted in fall-prevention interventions. These findings should be used to better understand and target the mechanisms of balance loss and falls in older adults following FFSs.
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Affiliation(s)
- Héloïse Debelle
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Carla Harkness-Armstrong
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Kathryn Hadwin
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Constantinos N Maganaris
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Thomas D O'Brien
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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12
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Mohamed Suhaimy MSB, Okubo Y, Hoang PD, Lord SR. Reactive Balance Adaptability and Retention in People With Multiple Sclerosis: A Systematic Review and Meta-Analysis. Neurorehabil Neural Repair 2020; 34:675-685. [PMID: 32507036 DOI: 10.1177/1545968320929681] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Aim. To compare reactive balance in people with multiple sclerosis (MS) with healthy controls and to examine the ability of people with MS to adapt their reactive balance and retain training effects. Data Sources. Electronic databases (PubMed, EMBASE, PsychINFO) and reference lists of included articles from inception to February 25, 2019. Study Selection. Case-control and intervention studies that assessed reactive balance using mechanical perturbations in people with a confirmed diagnosis of MS. Results. Meta-analyses of 9 studies (n = 342) showed that people with MS have significantly worse reactive balance than healthy controls (standardized mean difference [SMD] 0.78, 95% CI 0.44-1.11, P < .0001, I2 = 47%). Specifically, people with MS have greater center of mass displacements (SMD 0.41, 95% CI 0.05-0.77, P = .02, I2 = 9%) and longer response times (MD (ms) 31.45, 95% CI 19.91-42.98, P < .0001, I2 = 75%) in response to standing perturbations than healthy controls. Subsequent meta-analyses revealed training comprising repeated exposure to perturbations improved response times (P < .001) and training effects on response times could be retained for 24 hours (P < .001) in people with MS. Conclusions. Reactive balance assessments can highlight functional impairments related to falls in people with MS, and perturbation training can acutely improve reactive balance control and such improvements can be retained for 24 hours in this population. Systematic review registration number: CRD42019126130.
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Affiliation(s)
| | - Yoshiro Okubo
- University of New South Wales, Sydney, New South Wales, Australia.,Neuroscience Research Australia, Sydney, New South Wales, Australia
| | - Phu D Hoang
- University of New South Wales, Sydney, New South Wales, Australia.,Neuroscience Research Australia, Sydney, New South Wales, Australia
| | - Stephen R Lord
- University of New South Wales, Sydney, New South Wales, Australia.,Neuroscience Research Australia, Sydney, New South Wales, Australia
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13
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Rice PE, Nimphius S. When Task Constraints Delimit Movement Strategy: Implications for Isolated Joint Training in Dancers. Front Sports Act Living 2020; 2:49. [PMID: 33345041 PMCID: PMC7739566 DOI: 10.3389/fspor.2020.00049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/07/2020] [Indexed: 12/18/2022] Open
Abstract
Athletic performance is determined by numerous variables that cannot always be controlled or modified. Due to aesthetic requirements during sports such as dance, body alignment constrains possible movement solutions. Increased power transference around the ankle-joint, coupled with lower hip-joint power, has become a preferential strategy in dancers during leaps and may be considered a dance-specific stretch-shortening cycle (SSC) demand. Newell's theoretical model of interacting constraints includes organismic (or individual), environmental, and task constraints describing the different endogenous and exogenous constraints individuals must overcome for movement and athletic performance. The unique task constraints imposed during dance will be used as a model to justify an isolated joint, single-targeted block progression training to improve physical capacity within the context of motor behavior to enhance dance-specific SSC performance. The suggested ankle-specific block progression consists of isometrics, dynamic constant external resistance, accentuated eccentrics, and plyometrics. Such programming tactics intend to collectively induce tendon remodeling, muscle hypertrophy, greater maximal strength, improved rate of force development, increased motor unit firing rates, and enhanced dynamic movement performance. The current perspective provides a dualistic approach and justification (physiological and motor behavioral) for specific strength and conditioning programming strategies. We propose implementation of a single-targeted block progression program, inspired by Newell's theoretical model of interacting constraints, may elicit positive training adaptations in a directed manner in this population. The application of Newell's theoretical model in the context of a strength and conditioning supports development of musculoskeletal properties and control and is conceptually applicable to a range of athletes.
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Affiliation(s)
- Paige E Rice
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, United States
| | - Sophia Nimphius
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
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14
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Wang Y, Wang S, Bolton R, Kaur T, Bhatt T. Effects of task-specific obstacle-induced trip-perturbation training: proactive and reactive adaptation to reduce fall-risk in community-dwelling older adults. Aging Clin Exp Res 2020; 32:893-905. [PMID: 31321743 DOI: 10.1007/s40520-019-01268-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 07/01/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND Trips account for over half of outdoor falls among community-dwelling older adults. AIMS To investigate to what extent obstacle-induced trip-perturbation training could reduce fall-risk among older adults and to see whether training effects could be retained short term. METHODS Forty community-dwelling older adults were exposed to 24 repeated trip-perturbations given in a "blocked-and-mixed" manner during over-ground gait. Another trip was given 30 min post-training. For each trip, recovery strategies and outcomes (fall versus no fall) were analyzed. Within-trial changes to proactive and reactive dynamic center of mass stability, pre-trip toe clearance and trunk angle, trunk angle at recovery completion, and recovery step length were analyzed. RESULTS 48% of participants fell on their novel trip. The fall rate decreased significantly for subsequent trips, with no falls on the last trip. The decreased fall incidence resulted from improved feedforward and feedback adjustments for controlling center of mass stability and body kinematics. Proactive adaptations included reduced forward center of mass velocity, which lessened forward instability, and larger toe clearance, which increased the likelihood of obstacle avoidance. Reactive adjustments included reduced forward instability and improved trunk control (reduced forward rotation) at recovery step completion. Post-training, training effects were retained in terms of fall incidence, with slight decay in toe clearance and reactive stability. CONCLUSIONS Older adults demonstrated appropriate locomotor-based proactive and reactive adaptations to repeated obstacle-induced trips with short-term retention similar to young adults, and thus could reduce their fall-risk through such training.
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Affiliation(s)
- Yiru Wang
- Department of Physical Therapy, College of Applied Health and Sciences, University of Illinois at Chicago, 1919 West Taylor Street (M/C 898), Chicago, IL, 60612, USA
- PhD Program in Rehabilitation Sciences, College of Applied Health and Sciences, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Shuaijie Wang
- Department of Physical Therapy, College of Applied Health and Sciences, University of Illinois at Chicago, 1919 West Taylor Street (M/C 898), Chicago, IL, 60612, USA
| | - Ryan Bolton
- College of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Tanjeev Kaur
- College of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Tanvi Bhatt
- Department of Physical Therapy, College of Applied Health and Sciences, University of Illinois at Chicago, 1919 West Taylor Street (M/C 898), Chicago, IL, 60612, USA.
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15
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Transfer and retention effects of gait training with anterior-posterior perturbations to postural responses after medio-lateral gait perturbations in older adults. Clin Biomech (Bristol, Avon) 2020; 75:104988. [PMID: 32174482 DOI: 10.1016/j.clinbiomech.2020.104988] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/18/2019] [Accepted: 03/03/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Gait perturbations, occurring in any direction in daily life, may result in a fall. In fall prevention, gait perturbation training is a promising approach. Treadmill perturbations in anterior-posterior direction can easily be applied by accelerations or decelerations of the belt, but it is unknown whether training effects transfer to reactive recovery in medio-lateral direction. We aimed to evaluate the transfer and retention effects of gait training with treadmill perturbations in anterior-posterior direction to medio-lateral reactive recovery. METHODS 30 community dwelling older adults (>65 years) participated in this study. They were randomly assigned to a treadmill training session either with 16 anterior-posterior perturbations or with treadmill walking. The assessments contained a walking trial with 4 anterior-posterior and 4 medio-lateral perturbations. Deviations in trunk velocity from unperturbed walking were summed over the first three strides after perturbation as a measure of recovery. FINDINGS An exposure to gait perturbations during the baseline assessment led to significant improvement of recovery responses. For anterior-posterior perturbations, both groups showed better recovery immediately and 1-week post-intervention, and no group x time interaction was found.. For medio-lateral perturbations, both groups showed better recovery immediately and 1-week post-intervention, and again no group × time interaction. INTERPRETATION Baseline assessment with perturbations in anterior-posterior and medio-lateral directions caused significant improvements that were retained. Short-term training can be effective in dynamic stabilization of one's trunk, but our findings do not exclude that multi-directional perturbations may be needed.
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16
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Older adults demonstrate interlimb transfer of reactive gait adaptations to repeated unpredictable gait perturbations. GeroScience 2019; 42:39-49. [PMID: 31776885 PMCID: PMC7031170 DOI: 10.1007/s11357-019-00130-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 10/22/2019] [Indexed: 11/29/2022] Open
Abstract
The ability to rapidly adjust gait to cope with unexpected mechanical perturbations declines with ageing. Previous studies, however, have not ensured that gait stability pre-perturbation was equivalent across participants or age groups which may have influenced the outcomes. In this study, we investigate if age-related differences in stability following gait perturbations remain when all participants walk with equivalent stability. We also examine if interlimb transfer of gait adaptations are observed in healthy older adults, by examining if adaptation to repeated perturbations of one leg can benefit stability recovery when the other leg is perturbed. During walking at their stability-normalised walking speeds (young: 1.32 ± 0.07 m/s; older: 1.31 ± 0.13 m/s; normalised to an average margin of stability of 0.05 m), 30 young and 28 older healthy adults experienced ten unpredictable treadmill belt accelerations (the first and last applied to the right leg, the others to the left leg). Using kinematic data, we assessed the margins of stability during unperturbed walking and the first eight post-perturbation recovery steps. Older adults required three more steps to recover during the first perturbation to each leg than the young adults. Yet, after repeated perturbations of the left leg, older adults required only one more step to recover. Interestingly, for the untrained right leg, the older adults could regain stability with three fewer steps, indicating interlimb transfer of the improvements. Age differences in reactive gait stability remain even when participants’ walk with equivalent stability. Furthermore, we show that healthy older adults can transfer improvements in balance recovery made during repeated perturbations to one limb to their recovery following a perturbation to the untrained limb.
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König M, Epro G, Seeley J, Potthast W, Karamanidis K. Retention and generalizability of balance recovery response adaptations from trip perturbations across the adult life span. J Neurophysiol 2019; 122:1884-1893. [DOI: 10.1152/jn.00380.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
For human locomotion, varying environments require adjustments of the motor system. We asked whether age affects gait balance recovery adaptation, its retention over months, and the transfer of adaptation to an untrained reactive balance task. Healthy adults (26 young, 27 middle-aged, and 25 older; average ages 24, 52, and 72 yr, respectively) completed two tasks. The primary task involved treadmill walking: either unperturbed (control; n = 39) or subject to unexpected trip perturbations (training; n = 39). A single trip perturbation was repeated after a 14-wk retention period. The secondary transfer task, before and after treadmill walking, involved sudden loss of balance in a lean-and-release protocol. For both tasks, the anteroposterior margin of stability (MoS) was calculated at foot touchdown. For the first (i.e., novel) trip, older adults required one more recovery step ( P = 0.03) to regain positive MoS compared with younger, but not middle-aged, adults. However, over several trip perturbations, all age groups increased their MoS for the first recovery step to a similar extent (up to 70%) and retained improvements over 14 wk, although a decay over time was found for older adults ( P = 0.002; middle-aged showing a tendency for decay: P = 0.076). Thus, although adaptability in reactive gait stability control remains effective across the adult life span, retention of adaptations over time appears diminished with aging. Despite these robust adaptations, the perturbation training group did not show superior improvements in the transfer task compared with age-matched controls (no differences in MoS changes), suggesting that generalizability of acquired fall-resisting skills from gait-perturbation training may be limited. NEW & NOTEWORTHY The human neuromotor system preserves its adaptability across the adult life span. However, although adaptability in reactive gait stability control remains effective as age increases, retention of recovery response adaptations over time appears to be reduced with aging. Furthermore, acquired fall-resisting skills from single-session perturbation training seem task specific, which may limit the generalizability of such training to the variety of real-life falls.
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Affiliation(s)
- Matthias König
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - Gaspar Epro
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - John Seeley
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
| | - Wolfgang Potthast
- Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Cologne, Germany
| | - Kiros Karamanidis
- Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, London, United Kingdom
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18
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Karamanidis K, Epro G, McCrum C, König M. Improving Trip- and Slip-Resisting Skills in Older People: Perturbation Dose Matters. Exerc Sport Sci Rev 2019; 48:40-47. [DOI: 10.1249/jes.0000000000000210] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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19
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Rasmussen CM, Hunt NH. A novel wearable device to deliver unconstrained, unpredictable slip perturbations during gait. J Neuroeng Rehabil 2019; 16:118. [PMID: 31623680 PMCID: PMC6798496 DOI: 10.1186/s12984-019-0602-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/30/2019] [Indexed: 01/14/2023] Open
Abstract
Background Task-specific perturbation training is a widely studied means of fall prevention, utilizing techniques that induce slips or slip-like perturbations during gait. Though effective, these methods only simulate narrow ranges within the larger space of possible slipping conditions encountered in daily life. Here we describe and test a novel, wearable apparatus designed to address these limitations and simulate a diverse range of slipping disturbances. Methods The device consists of wireless triggering and detachable outsole components that provide adequate friction with the floor when secured to the wearer’s foot, but suddenly create a low-friction surface underfoot upon release. “Benchtop” tests were carried out to quantify device triggering characteristics (i.e. cutting temperature, release delay) and the resulting friction reduction. The device was also tested on six healthy young adults (3 female, age 23 ± 2.4 years), who walked with and without the device to observe how gait kinematics and spatiotemporal parameters were influenced, then performed 12 walking trials ending with a slip delivered by the device. Each participant also completed a survey to obtain opinions on device safety, device comfort, slip realism, and slip difficulty. A linear mixed effects analysis was employed to compare subject spatiotemporal parameters with and without the apparatus, as well as correlation coefficients and root mean square errors (RMSE) to assess the impact of the device on lower limb gait kinematics. Slip onset phases, distances, directions, velocities, and recovery step locations were also calculated. Results This device rapidly diminishes available friction from static coefficients of 0.48 to 0.07, albeit after a substantial delay (0.482 ± 0.181 s) between signal reception and outsole release. Strong correlations (R > 0.93) and small RMSE between gait kinematics with and without the device indicate minimal effects on natural gait patterns, however some spatiotemporal parameters were significantly impacted. A diverse range of slip perturbations and recovery steps were successfully elicited by the device. Conclusions Our results highlight the efficacy and utility of a wearable slipping device to deliver diverse slip conditions. Such an apparatus enables the study of unconstrained slips administered across the gait cycle, as well as during different locomotor behaviors like turning, negotiating slopes, and level changes.
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Affiliation(s)
- Corbin M Rasmussen
- Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE, 68182, USA.
| | - Nathaniel H Hunt
- Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE, 68182, USA
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20
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Dusane S, Wang E, Bhatt T. Transfer of reactive balance adaptation from stance-slip perturbation to stance-trip perturbation in chronic stroke survivors. Restor Neurol Neurosci 2019; 37:469-482. [PMID: 31561399 DOI: 10.3233/rnn-190924] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Chronic stroke survivors demonstrate the potential to acquire reactive adaptations to external perturbations. However, such adaptations in postural stability and compensatory stepping responses are perturbation-type specific and the ability to generalize such adaptation to an opposing perturbation has not been studied. OBJECTIVE The study aimed to examine whether improved reactive balance control acquired through prior slip-perturbation training would positively transfer to, or interfere with, the reactive response to an unexpected novel trip. METHODS Twenty-six chronic stroke survivors were assigned to either the training group (TR) who received treadmill-induced slips (12 m/s2) while standing followed by a novel trip (16.8 m/s2) or the control group (TC) who experienced a single unannounced trip. The primary outcome measure was postural stability (examined by relative center of mass position (RCoMP) and velocity (RCoMV)) with step length and trunk angle being secondary measures. Perturbation outcome (fall vs recovery) and number of compensatory steps were also recorded. RESULTS The TR group showed an anterior shift in RCoMP via longer compensatory backward step and reduced number of steps from first to last slip-perturbation (p < 0.05). Post-slip adaptation, the TR group exhibited a more posterior RCoMP on the novel trip along with a longer forward step and decreased trunk flexion compared to the TC group (p < 0.05). CONCLUSIONS Chronic stroke survivors demonstrated improved direction-specific compensatory stepping response on a novel trip-perturbation following reactive adaptation to large-magnitude, stance-slip perturbation training.The present study investigates the ability of chronic stroke survivors to generalize motor adaptation from stance-slip perturbation training to a novel, diametrically opposing trip-perturbation. We report that people with chronic hemi-paretic stroke could execute the acquired adaptation in reactive postural stability to improve reactive stepping responses to a novel stance-trip perturbation via generation of a direction-specific effective compensatory stepping response, such that the training group demonstrated a longer forward compensatory step and better control of postural stability than the control group.
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Affiliation(s)
- Shamali Dusane
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois, Chicago, IL, USA
| | - Edward Wang
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois, Chicago, IL, USA
| | - Tanvi Bhatt
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois, Chicago, IL, USA
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21
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Murphy SL, Tapper EB, Blackwood J, Richardson JK. Why Do Individuals with Cirrhosis Fall? A Mechanistic Model for Fall Assessment, Treatment, and Research. Dig Dis Sci 2019; 64:316-323. [PMID: 30327964 DOI: 10.1007/s10620-018-5333-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/09/2018] [Indexed: 12/12/2022]
Abstract
Falls are prevalent for people with cirrhosis and commonly lead to loss of independence, reduced quality of life, and mortality. Despite a critical need for fall prevention in this population, cirrhosis-specific fall-related mechanisms are not well understood. We posit that most falls in this patient population are due to a coalescence of discrete subclinical impairments that are not typically detected at the point of care. The combined effect of these subtle age- and disease-related neurocognitive and muscular impairments leads to the inability to respond successfully to a postural perturbation within the available 300 to 400 ms. This article provides a conceptual model of physiological resilience to avoid a fall that focuses on attributes that underlie the ability to withstand a postural perturbation and their clinical evaluation. Evidence supporting this model in cirrhosis and other high fall risk conditions will be synthesized and suggestions for fall assessment and treatment will be discussed.
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Affiliation(s)
- Susan L Murphy
- Department of Physical Medicine and Rehabilitation, University of Michigan, 24 Frank Lloyd Wright Drive, PO Box 344, Ann Arbor, MI, 48106, USA. .,Geriatric Research, Education and Clinical Center, Veterans Affairs Ann Arbor Health Care System, Ann Arbor, MI, USA.
| | - Elliot B Tapper
- Department of Internal Medicine, Division of Gasteroenterology, University of Michigan, Ann Arbor, MI, USA. .,Veterans Affairs Ann Arbor Health Care System, Ann Arbor, MI, USA.
| | - Jennifer Blackwood
- Department of Physical Therapy, University of Michigan - Flint Campus, Flint, MI, USA
| | - James K Richardson
- Department of Physical Medicine and Rehabilitation, University of Michigan, Ann Arbor, MI, USA
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22
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König M, Epro G, Seeley J, Catalá-Lehnen P, Potthast W, Karamanidis K. Retention of improvement in gait stability over 14 weeks due to trip-perturbation training is dependent on perturbation dose. J Biomech 2019; 84:243-246. [DOI: 10.1016/j.jbiomech.2018.12.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/08/2018] [Accepted: 12/06/2018] [Indexed: 11/29/2022]
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23
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McCrum C, Karamanidis K, Willems P, Zijlstra W, Meijer K. Retention, savings and interlimb transfer of reactive gait adaptations in humans following unexpected perturbations. Commun Biol 2018; 1:230. [PMID: 30564751 PMCID: PMC6294781 DOI: 10.1038/s42003-018-0238-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 11/28/2018] [Indexed: 11/09/2022] Open
Abstract
Reactive locomotor adaptations are crucial for safe mobility, but remain relatively unexplored. Here we assess reactive gait adaptations, and their retention, savings and interlimb transfer. Using new methods to normalise walking speed and perturbation magnitude, we expose eighteen healthy adults to ten unexpected treadmill belt accelerations during walking (the first and last perturbing the right leg, the others perturbing the left leg) on two days, one month apart. Analysis of the margins of stability using kinematic data reveals that humans reactively adapt gait, improving stability and taking fewer recovery steps, and fully retain these adaptations over time. On re-exposure, retention and savings lead to further improvements in stability. Currently, the role of interlimb transfer is unclear. Our findings show that humans utilise retention and savings in reactive gait adaptations to benefit stability, but that interlimb transfer may not be exclusively responsible for improvements following perturbations to the untrained limb.
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Affiliation(s)
- Christopher McCrum
- 1Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, P.O. Box 616, Maastricht, 6200 MD The Netherlands.,2Institute of Movement and Sport Gerontology, German Sport University Cologne, Am Sportpark Müngersdorf 6, Cologne, 50933 Germany
| | - Kiros Karamanidis
- 3Sport and Exercise Science Research Centre, School of Applied Sciences, London South Bank University, 103 Borough Road, London, SE1 0AA UK
| | - Paul Willems
- 1Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, P.O. Box 616, Maastricht, 6200 MD The Netherlands
| | - Wiebren Zijlstra
- 2Institute of Movement and Sport Gerontology, German Sport University Cologne, Am Sportpark Müngersdorf 6, Cologne, 50933 Germany
| | - Kenneth Meijer
- 1Department of Nutrition and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, P.O. Box 616, Maastricht, 6200 MD The Netherlands
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