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Martino G, Beck ON, Ting LH. Voluntary muscle coactivation in quiet standing elicits reciprocal rather than coactive agonist-antagonist control of reactive balance. J Neurophysiol 2023; 129:1378-1388. [PMID: 37162064 PMCID: PMC10259861 DOI: 10.1152/jn.00458.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/04/2023] [Accepted: 05/06/2023] [Indexed: 05/11/2023] Open
Abstract
Muscle coactivation increases in challenging balance conditions as well as with advanced age and mobility impairments. Increased muscle coactivation can occur both in anticipation of (feedforward) and in reaction to (feedback) perturbations, however, the causal relationship between feedforward and feedback muscle coactivation remains elusive. Here, we hypothesized that feedforward muscle coactivation would increase both the body's initial mechanical resistance due to muscle intrinsic properties and the later feedback-mediated muscle coactivation in response to postural perturbations. Young adults voluntarily increased leg muscle coactivation using visual biofeedback before support-surface perturbations. In contrast to our hypothesis, feedforward muscle coactivation did not increase the body's initial intrinsic resistance to perturbations, nor did it increase feedback muscle coactivation. Rather, perturbations with feedforward muscle coactivation elicited a medium- to long-latency increase of feedback-mediated agonist activity but a decrease of feedback-mediated antagonist activity. This reciprocal rather than coactivation effect on ankle agonist and antagonist muscles enabled faster reactive ankle torque generation, reduced ankle dorsiflexion, and reduced center of mass (CoM) motion. We conclude that in young adults, voluntary feedforward muscle coactivation can be independently modulated with respect to feedback-mediated muscle coactivation. Furthermore, our findings suggest feedforward muscle coactivation may be useful for enabling quicker joint torque generation through reciprocal, rather than coactivated, agonist-antagonist feedback muscle activity. As such our results suggest that behavioral context is critical to whether muscle coactivation functions to increase agility versus stability.NEW & NOTEWORTHY Feedforward and feedback muscle coactivation are commonly observed in older and mobility impaired adults and are considered strategies to improve stability by increasing body stiffness prior to and in response to perturbations. In young adults, voluntary feedforward coactivation does not necessarily increase feedback coactivation in response to perturbations. Instead, feedforward coactivation enabled faster ankle torques through reciprocal agonist-antagonist muscle activity. As such, coactivation may promote either agility or stability depending on the behavioral context.
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Affiliation(s)
- Giovanni Martino
- Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Tech, Atlanta, Georgia, United States
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Owen N Beck
- Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Tech, Atlanta, Georgia, United States
- Department of Kinesiology and Health Education, University of Texas at Austin, Austin, Texas, United States
| | - Lena H Ting
- Wallace H. Coulter Department of Biomedical Engineering, Emory University and Georgia Tech, Atlanta, Georgia, United States
- Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, Georgia, United States
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Brüll L, Hezel N, Arampatzis A, Schwenk M. Comparing the Effects of Two Perturbation-Based Balance Training Paradigms in Fall-Prone Older Adults: A Randomized Controlled Trial. Gerontology 2023; 69:910-922. [PMID: 36921581 DOI: 10.1159/000530167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/08/2023] [Indexed: 03/17/2023] Open
Abstract
INTRODUCTION There is increasing evidence that perturbation-based balance training (PBT) is highly effective in preventing falls at older age. Different PBT paradigms have been presented so far, yet a systematic comparison of PBT approaches with respect to feasibility and effectiveness is missing. Two different paradigms of PBT seem to be promising for clinical implementation: (1) technology-supported training on a perturbation treadmill (PBTtreadmill); (2) training of dynamic stability mechanisms in the presence of perturbations induced by unstable surfaces (PBTstability). This study aimed to compare both program's feasibility and effectiveness in fall-prone older adults. METHODS In this three-armed randomized controlled trial, seventy-one older adults (74.9 ± 6.0 years) with a verified fall risk were randomly assigned into three groups: PBTtreadmill on a motorized treadmill, PBTstability using unstable conditions such as balance pads, and a passive control group (CG). In both intervention groups, participants conducted a 6-week intervention with 3 sessions per week. Effects were assessed in fall risk (Brief-BEST), balance ability (Stepping Threshold Test, center of pressure, limits of stability), leg strength capacity, functional performance (Timed Up and Go Test, Chair-Stand), gait (preferred walking speed), and fear of falling (Short FES-I). RESULTS Fifty-one participants completed the study. Training adherence was 91% for PBTtreadmill and 87% for PBTstability, while no severe adverse events occurred. An analysis of covariance with an intention-to-treat approach revealed statistically significant group effects in favor of PBTstability in the Brief-BEST (p = 0.009, η2 = 0.131) and the limits of stability (p = 0.020, η2 = 0.110) and in favor of PBTtreadmill in the Stepping Threshold Test (p < 0.001, η2 = 0.395). The other outcomes demonstrated no significant group effects. CONCLUSION Both training paradigms demonstrated high feasibility and were effective in improving specific motor performances in the fall-prone population and these effects were task specific. PBTtreadmill showed higher improvements in reactive balance, which might have been promoted by the unpredictable nature of the included perturbations and the similarity to the tested surface perturbation paradigm. PBTstability showed more wide-ranging effects on balance ability. Consequently, both paradigms improved fall risk-associated measures. The advantages of both formats should be evaluated in light of individual needs and preferences. Larger studies are needed to investigate the effects of these paradigms on real-life fall rates.
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Affiliation(s)
- Leon Brüll
- Network Aging Research, Heidelberg University, Heidelberg, Germany,
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany,
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany,
| | - Natalie Hezel
- Network Aging Research, Heidelberg University, Heidelberg, Germany
- Geriatric Center, Heidelberg University Hospital, Agaplesion Bethanien Hospital Heidelberg, Heidelberg, Germany
| | - Adamantios Arampatzis
- Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin School of Movement Science, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Michael Schwenk
- Network Aging Research, Heidelberg University, Heidelberg, Germany
- Institute of Sports and Sports Sciences, Heidelberg University, Heidelberg, Germany
- Department of Sport Science, Human Performance Research Center, University of Konstanz, Konstanz, Germany
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Blodgett JM, Hardy R, Davis DHJ, Peeters G, Hamer M, Kuh D, Cooper R. Prognostic accuracy of the one-legged balance test in predicting falls: 15-years of midlife follow-up in a British birth cohort study. Front Sports Act Living 2023; 4:1066913. [PMID: 36699981 PMCID: PMC9869374 DOI: 10.3389/fspor.2022.1066913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/06/2022] [Indexed: 01/11/2023] Open
Abstract
Introduction The one-legged balance test is a common screening tool for fall risk. Yet, there is little empirical evidence assessing its prognostic ability. The study aims were to assess the prognostic accuracy of one-legged balance performance in predicting falls and identify optimal cut-points to classify those at greater risk. Methods Data from up to 2,000 participants from a British birth cohort born in 1,946 were used. The times an individual could stand on one leg with their eyes open and closed were recorded (max: 30 s) at ages 53 and 60-64. Number of falls in the past year was self-reported at ages 53, 60-64 and 68; recurrent falls (0-1 vs. 2+) and any fall (0 vs. 1+) were considered binary outcomes. Four longitudinal associations between balance times and subsequent falls were investigated (age 53 → 60-64; age 53 → 68; age 60-64 → 68; age 53 & 60-64 → 68). For each temporal association, areas under the curve (AUC) were calculated and compared for a base sex-only model, a sex and balance model, a sex and fall history model and a combined model of sex, balance and fall history. The Liu method was used to identify optimal cut-points and sensitivity, specificity, and AUC at corresponding cut-points. Results Median eyes open balance time was 30 s at ages 53 and 60-64; median eyes closed balance times were 5 s and 3 s, respectively. The predictive ability of balance tests in predicting either fall outcome was poor (AUC range for sex and balance models: 0.577-0.600). Prognostic accuracy consistently improved by adding fall history to the model (range: 0.604-0.634). Optimal cut-points ranged from 27 s to 29 s for eyes open and 3 s to 5 s for eyes closed; AUC consistently indicated that using "optimal" cut-points to dichotomise balance time provided no discriminatory ability (AUC range:0.42-0.47), poor sensitivity (0.38-0.61) and poor specificity (0.23-0.56). Discussion Despite previous observational evidence showing associations between better one-legged balance performance and reduced fall risk, the one-legged balance test had limited prognostic accuracy in predicting recurrent falls. This contradicts ongoing translation of this test into clinical screening tools for falls and highlights the need to consider new and existing screening tools that can reliably predict fall risk.
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Affiliation(s)
- Joanna M. Blodgett
- Institute of Sport, Exercise & Health, Division of Surgery & Interventional Science, University College London, London, UK
| | - Rebecca Hardy
- School of Sport, Exercise and Health Sciences,Loughborough University, Loughborough, UK
- Social Research Institute, University College London, London, UK
| | | | - Geeske Peeters
- Department of Geriatric Medicine, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Mark Hamer
- Institute of Sport, Exercise & Health, Division of Surgery & Interventional Science, University College London, London, UK
| | - Diana Kuh
- MRC Unit for Lifelong Health and Ageing, UCL, London, UK
| | - Rachel Cooper
- Department of Sport and Exercise Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University Institute of Sport, Manchester, UK
- AGE Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle University and Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
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Roldán García B, Esbrí Víctor M, López-Jiménez E, Gómez Ballesteros C, Alcantud Córcoles R, Andrés Pretel F, Sánchez-Jurado PM, Avendaño Céspedes A, Sánchez-Flor Alfaro V, López Bru R, Ruíz Grao MC, Noguerón García A, Romero Rizos L, García Molina R, Izquierdo M, Abizanda P. Limits of stability and falls during a multicomponent exercise program in faller older adults: A retrospective cohort study. Exp Gerontol 2022; 169:111957. [PMID: 36150587 DOI: 10.1016/j.exger.2022.111957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 06/06/2022] [Accepted: 09/16/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND/OBJETIVES Multicomponent exercise programs have been demonstrated to prevent falls in older adults. However, the underlying responsible mechanisms are not clear. We aimed to analyze the association between changes in the limits of stability (LOS) as a relevant balance component, and falls occurrence during a multicomponent physical exercise program. METHODS Retrospective study, including ninety-one participants who had experienced a fall in the previous year, and were attended in a falls unit. All of them were included in a twice-a-week multicomponent exercise program during 16 weeks. Pre- and post-program measurements were collected for leg press, gait speed, the short physical performance battery (SPPB), and LOS (point of excursion [POE] and maximal excursion [MEX]) with posturography. Falls occurrence was assessed between the beginning and the completion of the exercise program (16 week). RESULTS The mean age was 77.2 years, and 72 were female. Thirty-two participants fell at least once during the exercise period. The global baseline POE was 47.6 %, and the MEX was 64.7 %, and there were no differences between fallers and nonfallers. Nonfallers presented greater improvements in POE (6.3 % versus 1.3 %; p < .05) and MEX (9.2 % versus 3.0 %; p < .01) than fallers. The POE and MEX were independently associated with a reduced probability of having had a fall, OR: 0.95 (95 % CI: 0.91 to 0.99) and 0.94 (95 % CI: 0.90 to 0.99), respectively. Changes in SPPB results or leg press strength were not associated with decreased falls. Adjusted probability of fall occurrence decreased by 5 % and 6 % per 1 % improvement in absolute values in POE and MEX, respectively. CONCLUSIONS Improvements in LOS after a multicomponent physical exercise program in older adults with previous falls may be associated with a decreased occurrence of falls.
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Affiliation(s)
- Belén Roldán García
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain
| | - Mariano Esbrí Víctor
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain
| | - Esther López-Jiménez
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain
| | | | | | - Fernando Andrés Pretel
- Department of Statistics, Foundation of the National Paraplegics Hospital of Toledo, Toledo, Spain
| | - Pedro Manuel Sánchez-Jurado
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, Spain
| | - Almudena Avendaño Céspedes
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Facultad de Enfermería de Albacete, Universidad de Castilla-La Mancha, Spain
| | | | - Rita López Bru
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain
| | | | | | - Luis Romero Rizos
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, Spain
| | - Rafael García Molina
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain; Department of Statistics, Foundation of the National Paraplegics Hospital of Toledo, Toledo, Spain
| | - Míkel Izquierdo
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Navarrabiomed, Hospital Universitario de Navarra (HUN), Navarra Institute for Health Research (IdiSNA), Universidad Pública de Navarra (UPNA), Pamplona, Spain
| | - Pedro Abizanda
- Geriatrics Department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Facultad de Medicina de Albacete, Universidad de Castilla-La Mancha, Spain.
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