Postural Control in Older Adults During and Following a 12-Week Balance Training Intervention With Attentional Focus Instructions

2021 ◽  
pp. 1-26
Author(s):  
Lauren Q. Higgins ◽  
Jeffrey D. Labban ◽  
Ruth D. Stout ◽  
Jeffrey T. Fairbrother ◽  
Christopher K. Rhea ◽  
...  
Keyword(s):  
Postural Control ◽  
Growth Models ◽  
Piecewise Linear ◽  
Balance Training ◽  
Attentional Focus ◽  
Self Report ◽  
Individual Growth ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Mean Velocity

Adults (N = 54, 80.78 ± 6.08 years) who reported falling during the previous 12 months participated in a 12-week wobble board training program with internal focus or external focus (EF) instructions. Verbal manipulation checks were performed after training sessions as a self-report of the attentional foci used. The percentage of sessions in which participants reported using an EF (EFSR) was subsequently calculated. Mean velocity and mean power frequency in the anterior–posterior (MVELOAP and MPFAP) and medial–lateral (MVELOML and MPFML) direction were assessed during a 35-s wobble board task at Weeks 0, 6, 12, 13, 16, and 20, with the latter three as retention tests. Piecewise linear growth models estimated treatment effects on individual growth trajectories of MVELOAP and ML and MPFAP and ML during intervention and retention periods. Regardless of condition, MVELOML significantly decreased (π = −.0019, p = .005) and MPFML increased (π = .025, p < .02) during the intervention period. In analyses including interaction terms, participants in the EF group who reported greater EFSR had superior progression of MPFAP during the intervention (π = .0013, p = .025). Verbal manipulation checks suggest a preference for and advantage of EF for facilitating postural control performance and automaticity.

Surface height effects on postural control: A hypothesis for a stiffness strategy for stance*

1999 ◽  
Vol 9 (4) ◽  
pp. 277-286 ◽  
Author(s):  
Mark G. Carpenter ◽  
James S. Frank ◽  
Cathy P. Silcher
Keyword(s):  
Postural Control ◽  
Center Of Pressure ◽  
High Surface ◽  
Quiet Standing ◽  
Vestibular Input ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Balance Confidence ◽  
Eyes Closed ◽  
Ankle Stiffness

One possible factor influencing the control of upright stance is the perceived threat to one's personal safety, i.e. balance confidence. We explored this factor by examining the control of stationary stance when standing on an elevated platform under various conditions of reduced visual and vestibular inputs. Twenty-eight adults (14 male and 14 female, mean age = 23.5 years) participated in the experiment. Postural control was examined by recording the amplitude variability (RMS) and mean power frequency (MPF) of center of pressure excursions (COP) over a 2-minute interval while participants stood in a normal stance on a low (0.19 m) and a high (0.81 m) platform with toes positioned either at or away from the edge of the platform. Vision was manipulated through eyes open and eyes closed trials. Vestibular input was reduced by tilting the head into extension [1]. Anterior-posterior RMS and MPF of COP were significantly influenced by an interaction between surface height and vision. When vision was available, a significant decrease in RMS was observed during quiet standing on a high surface compared to a low surface independent of step restriction. When vision was available MPF increased when subjects were raised from a low to a high surface. The mean position of the COP was significantly influenced by an interaction between height and step restriction. Differences in RMS and MPF responses to height manipulation were observed between genders in eyes closed conditions. Vestibular input influenced postural control at both low and high levels with significant increases in RMS when vestibular input was reduced. The reciprocal changes observed in RMS and MPF suggest modifications to postural control through changes in ankle stiffness. Vision appears to play a role in increasing ankle stiffness when balance confidence is compromised.

scholarly journals Attentional demands associated with augmented visual feedback during quiet standing

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5101 ◽  
Author(s):  
Krzysztof Kręcisz ◽  
Michał Kuczyński
Keyword(s):  
Postural Control ◽  
Visual Feedback ◽  
Center Of Pressure ◽  
Quiet Standing ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Postural Control System ◽  
Power Frequency ◽  
Auditory Reaction Time ◽  
Anterior Posterior

To investigate how additional visual feedback (VFB) affects postural stability we compared 20-sec center-of-pressure (COP) recordings in two conditions: without and with the VFB. Seven healthy adult subjects performed 10 trials lasting 20 seconds in each condition. Simultaneously, during all trials the simple auditory reaction time (RT) was measured. Based on the COP data, the following sway parameters were computed: standard deviation (SD), mean speed (MV), sample entropy (SE), and mean power frequency (MPF). The RT was higher in the VFB condition (p < 0.001) indicating that this condition was attention demanding. The VFB resulted in decreased SD and increased SE in both the medial-lateral (ML) and anterior-posterior (AP) planes (p < .001). These results account for the efficacy of the VFB in stabilizing posture and in producing more irregular COP signals which may be interpreted as higher automaticity and/or larger level of noise in postural control. The MPF was higher during VFB in both planes as was the MV in the AP plane only (p < 0.001). The latter data demonstrate higher activity of postural control system that was caused by the availability of the set-point on the screen and the resulting control error which facilitated and sped up postural control.

Intramuscular and surface electromyogram changes during muscle fatigue

1986 ◽  
Vol 60 (4) ◽  
pp. 1179-1185 ◽  
Author(s):  
T. Moritani ◽  
M. Muro ◽  
A. Nagata
Keyword(s):  
Muscle Fatigue ◽  
Biceps Brachii ◽  
Surface Emg ◽  
Firing Frequency ◽  
Voluntary Contraction ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Surface Electromyogram ◽  
Spike Amplitude ◽  
Frequency Power

Twelve male subjects were tested to determine the effects of motor unit (MU) recruitment and firing frequency on the surface electromyogram (EMG) frequency power spectra during sustained maximal voluntary contraction (MVC) and 50% MVC of the biceps brachii muscle. Both the intramuscular MU spikes and surface EMG were recorded simultaneously and analyzed by means of a computer-aided intramuscular spike amplitude-frequency histogram and frequency power spectral analysis, respectively. Results indicated that both mean power frequency (MPF) and amplitude (rmsEMG) of the surface EMG fell significantly (P less than 0.001) together with a progressive reduction in MU spike amplitude and firing frequency during sustained MVC. During 50% MVC there was a significant decline in MPF (P less than 0.001), but this decline was accompanied by a significant increase in rmsEMG (P less than 0.001) and a progressive MU recruitment as evidenced by an increased number of MUs with relatively large spike amplitude. Our data suggest that the surface EMG amplitude could better represent the underlying MU activity during muscle fatigue and the frequency powers spectral shift may or may not reflect changes in MU recruitment and rate-coding patterns.

scholarly journals Habitual Physical Activity as a Determinant of the Effect of Moderate Physical Exercise on Postural Control in Older Men

2012 ◽  
Vol 7 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Rafał Stemplewski ◽  
Janusz Maciaszek ◽  
Maciej Tomczak ◽  
Robert Szeklicki ◽  
Dorota Sadowska ◽  
...  
Keyword(s):  
Physical Activity ◽  
Postural Control ◽  
Sagittal Plane ◽  
Center Of Pressure ◽  
Force Plate ◽  
Frontal Plane ◽  
Habitual Physical Activity ◽  
Similar Reaction ◽  
Mean Velocity ◽  
Ergometer Exercise

The aim of the study was to compare the effect of exercise on postural control (PC) among the elderly with lower or higher level of habitual physical activity (HPA). The study involved 17 elderly men (mean age 72.9 ± 4.79 years). Mean velocity of the center of pressure (COP) displacements was measured using a force plate both before and after cycle ergometer exercise. A significantly higher increase in mean velocity of COP displacements and its component in the sagittal plane were observed in the group with lower level of HPA in comparison with the group with higher HPA level. Simultaneously, a relatively similar reaction to the exercise in the frontal plane was observed in both groups, possibly connected to the specific type of used exercise, which mainly activated the sagittal muscles.

scholarly journals Comparison of growth models to describe growth from birth to 6 years in a Beninese cohort of children with repeated measurements

BMJ Open ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. e035785
Author(s):  
Shukrullah Ahmadi ◽  
Florence Bodeau-Livinec ◽  
Roméo Zoumenou ◽  
André Garcia ◽  
David Courtin ◽  
...  
Keyword(s):  
Growth Model ◽  
Goodness Of Fit ◽  
Growth Models ◽  
Information Criterion ◽  
Height Growth ◽  
Sub Saharan Africa ◽  
Individual Growth ◽  
Secondary Outcome ◽  
Growth Trajectories ◽  
Best Fitting

ObjectiveTo select a growth model that best describes individual growth trajectories of children and to present some growth characteristics of this population.SettingsParticipants were selected from a prospective cohort conducted in three health centres (Allada, Sekou and Attogon) in a semirural region of Benin, sub-Saharan Africa.ParticipantsChildren aged 0 to 6 years were recruited in a cohort study with at least two valid height and weight measurements included (n=961).Primary and secondary outcome measuresThis study compared the goodness-of-fit of three structural growth models (Jenss-Bayley, Reed and a newly adapted version of the Gompertz growth model) on longitudinal weight and height growth data of boys and girls. The goodness-of-fit of the models was assessed using residual distribution over age and compared with the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The best-fitting model allowed estimating mean weight and height growth trajectories, individual growth and growth velocities. Underweight, stunting and wasting were also estimated at age 6 years.ResultsThe three models were able to fit well both weight and height data. The Jenss-Bayley model presented the best fit for weight and height, both in boys and girls. Mean height growth trajectories were identical in shape and direction for boys and girls while the mean weight growth curve of girls fell slightly below the curve of boys after neonatal life. Finally, 35%, 27.7% and 8% of boys; and 34%, 38.4% and 4% of girls were estimated to be underweight, wasted and stunted at age 6 years, respectively.ConclusionThe growth parameters of the best-fitting Jenss-Bayley model can be used to describe growth trajectories and study their determinants.

Postural control using a vibratory feedback system for balance training in the elderly

2008 ◽  
pp. 263-270
Author(s):  
T Ifukube ◽  
Y Oyama ◽  
S Shirogane ◽  
T Izumi ◽  
Y Maeda ◽  
...  
Keyword(s):  
Postural Control ◽  
Balance Training ◽  
Feedback System ◽  
The Elderly

scholarly journals Enhancement of Countermovement Jump Performance Using a Heavy Load with Velocity-Loss Repetition Control in Female Volleyball Players

2021 ◽  
Vol 18 (21) ◽  
pp. 11530
Author(s):  
Michal Krzysztofik ◽  
Rafal Kalinowski ◽  
Robert Trybulski ◽  
Aleksandra Filip-Stachnik ◽  
Petr Stastny
Keyword(s):  
Body Mass ◽  
Repeated Measures ◽  
Performance Enhancement ◽  
Countermovement Jump ◽  
Mean Power ◽  
Mean Velocity ◽  
Heavy Load ◽  
Jump Performance ◽  
Volleyball Players ◽  
Post Hoc

Although velocity control in resistance training is widely studied, its utilization in eliciting post-activation performance enhancement (PAPE) responses receives little attention. Therefore, this study aimed to evaluate the effectiveness of heavy-loaded barbell squats (BS) with velocity loss control conditioning activity (CA) on PAPE in subsequent countermovement jump (CMJ) performance. Sixteen resistance-trained female volleyball players participated in this study (age: 24 ± 5 yrs.; body mass: 63.5 ± 5.2 kg; height: 170 ± 6 cm; relative BS one-repetition maximum (1RM): 1.45 ± 0.19 kg/body mass). Each participant performed two different conditions: a set of the BS at 80% 1 RM with repetitions performed until a mean velocity loss of 10% as the CA or a control condition without CA (CNTRL). To assess changes in jump height (JH) and relative mean power output (MP), the CMJ was performed 5 min before and throughout the 10 min after the CA. The two-way analysis of variance with repeated measures showed a significant main effect of condition (p = 0.008; η2 = 0.387) and time (p < 0.0001; η2 = 0.257) for JH. The post hoc test showed a significant decrease in the 10th min in comparison to the value from baseline (p < 0.006) for the CNTRL condition. For the MP, a significant interaction (p = 0.045; η2 = 0.138) was found. The post hoc test showed a significant decrease in the 10th min in comparison to the values from baseline (p < 0.006) for the CNTRL condition. No significant differences were found between all of the time points and the baseline value for the CA condition. The CA used in the current study fails to enhance subsequent countermovement jump performance in female volleyball players. However, the individual analysis showed that 9 out of the 16 participants (56%) responded positively to the applied CA, suggesting that the PAPE effect may be individually dependent and should be carefully verified before implementation in a training program.

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