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

Vibration of the Whole Foot Soles Surface Using an Inexpensive Portable Device to Investigate Age-Related Alterations of Postural Control

“…Also, we recruited healthy and physically active older adults (>65 years) that are not representative of the general population, hence potentially underestimating the impact of age and comorbidities on the postural control system. Finally, guidelines about CoP measurements recommend at least 10 s for unipedal balance (Lin et al, 2008), and 10-20 s and more for the bipodal stance like in our study for reaching high reliability indices of CoP data (Parreira et al, 2013), but we preferred to restrict vibration to 10 s to replicate published protocols in the field of VIB-induced postural effects (Kadri et al, 2020). Future works should consider trying different vibration durations in order to determine the protocol offering the best balance between reliability, timeconsumption and fatigue build-up.…”

“…The vertical ground reaction force data from the force platform was sampled at 100 Hz. All force signals were filtered with a Butterworth second order low-pass 35 Hz filter (Kadri et al, 2020). Data was converted into stabilometric analyses using the BIOMEC software combined with MATLAB routines (The Mathworks, Natick, MA, United States).…”

“…The experimental session (60 min) assessed postural control in bipedal stance in three randomized conditions (10 s/condition; 5 trials/condition): (i) Baseline (standing on the vibration platform but without stimulation), (ii) VIB (cutaneous vibration applied to the whole surface of both feet), (iii) Foam (standing on a 20 × 16 × 2.5 balance pad, Airex Compagny, Switzerland). Duration of the postural measures in all conditions is established according to the duration of vibratory stimulation which, in a similar context (i.e., disruption of muscle spindles by tenon vibration), presents a good reliability for the CoP-based postural parameters (Kadri et al, 2020). Vibration was delivered at 50 Hz by the 40 vibrators (20/foot) of the portable vibration platform (PortVIBplate-see Lafontaine et al (2020)).…”

“…For all conditions, participants were asked to stand barefoot with eyes blindfolded and the arms along the body, and the feet position was standardized using marks on the PortVIBplate and Foam mat. The PortVIBplate and the foam mat were placed on a force platform (BIOMEC400, EMG System do Brazil, Ltda., SP) [for the characteristics see Kadri et al (2020)], to measure variables of postural control based on linear parameters of the center of pressure (CoP). Brief rest period of 1 min between each trial and each condition allowed participants to rest and remove the blindfold.…”

The Impact of Pain on Functionality, Postural Control and Fall Risk in Woman Aged 45 to 64 Years Old

“…The output range runs from 0 to 5 V. Reaction force signals were sampled at 100 Hz and filtered with a 35-Hz low-pass second-order Butterworth filter and converted into COP data using EMG system do Brasil software which was compiled with MATLAB routines (The Mathworks, Natick, MA, USA). Stabilographic analysis of COP data led to determine the following postural parameters during a 30-s trial: 95% confidence ellipse area of COP (named A-COP: the total area covered in the sagittal and frontal planes using an ellipse, cm 2 ) and COP mean Velocity (named VEL: the sum of the cumulated COP displacement divided by the total time, in cm 2 ) in the anteroposterior (AP) and mediolateral (ML) directions of movement [ 40 , 41 , 42 ]. These parameters have been widely used to reflect postural stability, efficiency of the postural control systems and postural performance, respectively, in a variety of contexts [ 40 , 41 , 42 ].…”