Time course and variability of tendinous vibration-induced postural reactions in forward and backward directions

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Abstract

Mechanical vibration of tendons induces large postural reactions (PR-VIB) but little is known about how these reactions vary within and between subjects. We investigated the intra- and inter-individual variability of PR-VIB and determined the reliability of center of pressure (COP) measures. Bipodal postural control (eyes closed) of 30 healthy adults were evaluated using a force platform under 02 conditions: bilateral VIB of the tibialis anterior (TA) and Achilles tendons (ACH-T) at 80 Hz. Each condition consisted of 03 trials of 30 s duration (Baseline: 10 s; VIB: 10 s; POST-VIB: 10 s). The Amplitude and Velocity of the COP in the antero-posterior/medio-lateral (AP/ML) directions were recorded and analyzed according to 5 time-windows incremented every 2 s of vibration (i.e. the first 2 s; 4 s; 6 s; 8 s & 10 s), whereas the COP position/AP was monitored every 0.5 s. All postural parameters increased significantly during TA and ACH-T vibration compared to the Baseline. The reliability of the COP measures showed good ICC scores (0.40-0.84) and measurement errors that varied depending on the duration of VIB time-windows. The COP position/AP reveals a lower intra- and inter-subject variability of PR-VIB in the first 2 s of VIB. The metrological characteristics of PR-VIB should be investigated further to guide their future use by clinicians and researchers.

Introduction

The mechanical vibration (VIB) of tendons is a painless and safe method to externally activate key proprioceptive afferents involved in postural control system, i.e. muscle spindles (Roll and Vedel, 1982, Roll et al., 1998, Kavounoudias et al., 1999, Kavounoudias et al., 2001, Hatzitaki et al., 2004, Duclos et al., 2007, Thompson et al., 2011, Duclos et al., 2014, Doumas et al., 2019). Microneurography studies have shown that muscle spindles of the vibrated tendon are particularly activated at vibration frequencies around 80 Hz (Roll and Vedel, 1982, Kavounoudias et al., 2001, Floyd et al., 2014). In the absence of visual feedback, the proprioceptive signal originating from the spindles and transmitted to the central nervous system (CNS) is interpreted as an ongoing stretching of the vibrated muscles (Kavounoudias et al., 2001, Floyd et al., 2014, Duclos et al., 2015). For instance, vibration applied to the Achilles tendons mimic the sensory feedback that would have been elicited during the stretching of calf muscles. In the presence of a normal postural control system, this false proprioceptive signal is interpreted as a forward fall, and a backward postural reaction occurs to maintain balance (Kavounoudias et al., 2001, Polonyova and Hlavacka, 2001).

On the other hand, the time course characteristics of these postural responses elicited by tendinous vibration (PR-VIB) seem to vary depending on the VIB duration. For instance, previous work reported that postural reactions increase in amplitude with longer VIB durations, until a plateau is reached (Čapičikova et al., 2006, Duclos et al., 2015). Currently, only one study explored the time course of COP (i.e. center of foot pressure) displacement by separating the vibration period in 5 successive 4 s periods (P1 to P5) during bilateral Achilles and/or Peroneus tendons vibration (Duclos et al., 2015). These authors observed a significant increase in COP Velocity and COP position from P1 (0 to 4 s) to P2 (4 to 8 s), regardless of the vibrated tendon. We believe that the precise dynamics of COP variables during early vs. late phases of PR-VIB could inform about different postural mechanisms that are critical to maintain balance during a disturbing environment. However, the process used so far in the literature to analyze COP displacement might not be sufficiently precise to capture the detailed dynamics of PR-VIB because the time intervals used (≥4s) could be longer than postural reaction times.

In addition, COP measures and PR-VIB depend on biological systems and could greatly vary both within and between-subjects, which could in turn compromise the reliability and the validity of postural control measures. Despite the extensive use of tendinous vibration in postural control assessment protocols, to our knowledge no study has been conducted to examine the intra- and inter-individual variability of PR-VIB and how it could influence their reliability. There are no published guidelines describing which COP parameters and VIB durations provide the best reliability. This knowledge is of utmost importance for future applications of the VIB tool. For instance, knowing the shorter stimulation period that can still provide valid and reliable measurements would make the PR-VIB method less time-consuming and more feasible for clinical and research applications.

Consequently, this study precisely characterized the time course and intra-/inter-individual variability of postural reactions induced by mechanical vibration of ankle tendons (Tibialis anterior and Achilles tendons) in adults having normal sensorimotor and postural systems. Additionally, test-retest reliability and minimal detectable changes of VIB-induced COP parameters were obtained to foster future clinical and research applications of PR-VIB.

Section snippets

Participants

Thirty healthy active subjects (7 men, 23 women) aged from 18 to 54 years old (<30 years: n = 28; >40 years: n = 2) with no prior history of functional impairment related to neurological, musculoskeletal, vestibular disorders and ankle, knee and hip injuries in the past 2 years participated voluntarily in the experiment. Participants gave their informed consent to participate in the experiment in accordance with the Declaration of Helsinki and the local research ethic committee. Participant’s

Global VIB effects on postural control

A significant effect (p < .01) between three periods (Baseline vs VIB vs POST-VIB) was found for all postural parameters for both TA and ACH-T conditions (Table 1). Bonferroni pairwise comparisons revealed a significant increase for all COP values during VIB and POST-VIB conditions compared to the Baseline (p < .00), regardless of the tendon vibrated. In addition, the after-effects of vibration were observed immediately after stopping the vibratory stimulation. Most COP postural parameters

Discussion

The present study was the first to precisely characterize the time course of postural reactions induced by VIB of TA and ACH-T tendons using 0.5 s intervals among adults with normal sensorimotor system. Also, we tested the influence of different VIB durations (i.e. 2 s, 4 s, 6 s, 8 s & 10 s) on the reliability of the selected COP outcome measures of postural control.

The global analysis of postural reactions confirmed the effectiveness of our VIB protocol. Indeed, our findings replicated those

Conclusion

The results underscored that longer durations of VIB provide more reliable COP-based variables of postural control, but also that reactions evolve dynamically with time. The early 2 s period seems characterized by a relatively stereotypical and homogenous postural imbalance across participants resulting from a rapid postural reaction to the false proprioceptive signal elicited by VIB. On the other hand, the following 8 s period is much more variable and might represent an adaptative phase to

Declaration of Competing Interest

None declared.

Mohamed Abdelhafid Kadri received a License degree in Sciences and Techniques of Physical and Sports Activities (STAPS) (2011), a Master degree in Sciences applied to sports (2013) from the University of Badji-Mokhtar (Annaba, Algéria) and Ph.D. degree in STAPS (the neurophysiology of muscle exercise and human posture; 2018) from the University of Pau et des pays de l’Adour (Pau, France). He is currently a postdoctoral fellowship at the biomechanical & neurophysiological research laboratory in

References (30)

  • H. Beckerman et al.

    Smallest real difference, a link between reproducibility and responsiveness

    Qual. Life Res.

    (2001)
  • N. Čapičikova et al.

    Human postural response to lower leg muscle vibration of different duration

    Physiol. Res.

    (2006)
  • R.A. Da Silva et al.

    Age-related differences on low back pain and postural control during one-leg stance: a case-control study

    Eur. Spine J.

    (2016)
  • R.A. Da Silva et al.

    People with chronic low back pain have poorer balance than controls in challenging tasks

    Disabil. Rehabil.

    (2017)
  • I. Di Giulio et al.

    The proprioceptive and agonist roles of gastrocnemius, soleus and tibialis anterior muscles in maintaining human upright posture

    The Journal of physiology

    (2009)
  • Cited by (0)

    Mohamed Abdelhafid Kadri received a License degree in Sciences and Techniques of Physical and Sports Activities (STAPS) (2011), a Master degree in Sciences applied to sports (2013) from the University of Badji-Mokhtar (Annaba, Algéria) and Ph.D. degree in STAPS (the neurophysiology of muscle exercise and human posture; 2018) from the University of Pau et des pays de l’Adour (Pau, France). He is currently a postdoctoral fellowship at the biomechanical & neurophysiological research laboratory in neuro-musculoskeletal rehabilitation (BioNR), and at the Research Center CISD since March 2019 (Université du Québec à Chicoutimi, QC, Canada). His areas of research focus particularly on the study of clinical and neurophysiological aspects of sensorimotor integration during postural control, with the use of innovative technologies such as vibratory stimulation.

    Gabrielle Chevalier received a B.Sc. degree in Rehabilitation Science (2017) and a M.Sc. in Physical Therapy (2018) from McGill University (program in extension at Université du Québec à Chicoutimi). She is currently working as a physical therapist.

    Hakim Mecheri is an Engineer who graduated from Université des Sciences et de la Technologie d’Oran (U.S.T.O) in Algeria. He acquired his Master degree from École de Technologie Supérieure (É.T.S) in Montreal, Québec, Canada. From 2003 to 2010 he was a lecturer for different courses at É.T.S. He is now a scientific professional at Institut de Recherche Robert Sauvé en Santé et en Sécurité du Travail (IRSST). His main research interests are biomechanics, signal processing and image processing.

    Suzy Ngomo holds a doctorate in General Medicine (1998), a master’s degree (MSc) in Research Sciences/Biological Sciences (2005) and a PhD in Experimental Medicine (2012). She went on to complete a postdoctoral internship at McGill University (2013). Professor – researcher and director of the Department of Health Sciences at Université du Québec à Chicoutimi (Quebec, Canada), Suzy Ngomo is interested in the interactions between pain and motor functions, as well as the optimization of the brain’s restorative abilities in the presence of changes to the neuro-musculoskeletal system.

    Martin Lavallière is a professor of kinesiology at the Department of health sciences at Université du Québec à Chicoutimi (UQAC). He currently serves as a board member of the Quebec national board of road safety (RRSR), the Canadian Association of Road Safety Professional (CARSP) and on different ISO committees in regards to driving and human machine interface.

    Rubens da Silva received a B.Sc. degree in Physiotherapy in 2000 and a Master and Ph.D. degree in Biomedical Sciences (Rehabilitation) in 2003 and 2008, respectively from the University of Montreal in Canada. He was a postdoctoral fellow at the Elisabeth Bruyere Research Institute affiliated to Ottawa University from 2008 (Canada) and a senior fellow at the Florida International University from 2016 (USA). Since 2017, he is an Associate professor at the Université du Québec à Chicoutimi (UQAC), and Adjunct professor at the McGill University (Quebec, Canada). He is titular member of research laboratory BioNR (UQAC), and of research center CISD. He is also researcher-professor in Doctoral and Master Rehabilitation in Science program at the UNOPAR University (Londrina-PR, BR). He is actually the director of physical therapy clinic in UQAC. His current research interests include the study of aging, postural control, falls prevention, low back pain, exercise, muscle fatigue.

    Louis-David Beaulieu received a B.Sc. degree in Physiotherapy (2010), a M.Sc. degree in Neurobiology (2012) and Ph.D. degree in experimental medicine (adaptation/rehabilitation concentration; 2016) from the Université Laval (Québec, QC, Canada). He then completed a postdoctoral fellowship at the Research Center on Aging of the CIUSSS de l’Estrie-CHUS from 2016 to 2017 (Université de Sherbrooke, QC, Canada). He is currently associate professor at the physical therapy program of the Université du Québec à Chicoutimi (Saguenay, QC, Canada). His research areas particularly focus on the study of clinical and neurophysiological aspects of sensorimotor recovery in neurological and musculoskeletal pathologies, with the use of innovative technologies such as non-invasive neurostimulation.

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