scholarly journals The Effect of Balance Task Difficulty and Visual Feedback on EMG Activity of Selected Muscles in Elderly Women

2019 ◽  
Vol 4 (2) ◽  
pp. 61-76
Author(s):  
حدیث کاویانی پور ◽  
علیرضا فارسی
Keyword(s):  
Visual Feedback ◽  
Task Difficulty ◽  
Elderly Women ◽  
Emg Activity ◽  
Balance Task

scholarly journals Effects of balance training on balance performance in youth: role of training difficulty

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Simon Schedler ◽  
Florian Tenelsen ◽  
Laura Wich ◽  
Thomas Muehlbauer
Keyword(s):  
Task Difficulty ◽  
Balance Training ◽  
Gait Velocity ◽  
Balance Performance ◽  
Timed Up And Go ◽  
Balance Test ◽  
Cross Sectional ◽  
Time Dynamic ◽  
Balance Task ◽  
Functional Reach Test

Abstract Background Cross-sectional studies have shown that balance performance can be challenged by the level of task difficulty (e.g., varying stance conditions, sensory manipulations). However, it remains unclear whether the application of different levels of task difficulty during balance training (BT) leads to altered adaptations in balance performance. Thus, we examined the effects of BT conducted under a high versus a low level of task difficulty on balance performance. Methods Forty male adolescents were randomly assigned to a BT program using a low (BT-low: n = 20; age: 12.4 ± 2.0 yrs) or a high (BT-high: n = 20; age: 12.5 ± 2.5 yrs) level of balance task difficulty. Both groups trained for 7 weeks (2 sessions/week, 30–35 min each). Pre- and post-training assessments included measures of static (one-legged stance [OLS] time), dynamic (10-m gait velocity), and proactive (Y-Balance Test [YBT] reach distance, Functional Reach Test [FRT]; Timed-Up-and-Go Test [TUG]) balance. Results Significant main effects of Test (i.e., pre- to post-test improvements) were observed for all but one balance measure (i.e., 10-m gait velocity). Additionally, a Test x Group interaction was detected for the FRT in favor of the BT-high group (Δ + 8%, p < 0.001, d = 0.35). Further, tendencies toward significant Test x Group interactions were found for the YBT anterior reach (in favor of BT-high: Δ + 9%, p < 0.001, d = 0.60) and for the OLS with eyes opened and on firm surface (in favor of BT-low: Δ + 31%, p = 0.003, d = 0.67). Conclusions Following 7 weeks of BT, enhancements in measures of static, dynamic, and proactive balance were observed in the BT-high and BT-low groups. However, BT-high appears to be more effective for increasing measures of proactive balance, whereas BT-low seems to be more effective for improving proxies of static balance. Trial registration Current Controlled Trials ISRCTN83638708 (Retrospectively registered 19th June, 2020).

Balance Performance under Varied Conditions of Sensory Cues

1982 ◽  
Vol 54 (3) ◽  
pp. 951-954 ◽  
Author(s):  
Jacqueline Shick
Keyword(s):  
High School ◽  
Visual Feedback ◽  
Junior High School ◽  
Junior High ◽  
Sensory Cues ◽  
Balance Performance ◽  
High School Girls ◽  
Balance Task ◽  
Partial Feedback ◽  
School Girls

43 junior-high-school girls performed three trials on a dynabilometer on each of seven days. After learning the balance task with all sensory cues available, subjects were tested under three conditions of partial feedback occlusion, i.e., with earphones, blindfold, and combination of earphone and blindfold. When visual feedback was absent, performance deteriorated significantly. Such deterioration did not occur when hearing was occluded.

scholarly journals Effects of Concurrent and Terminal Visual Feedback on Ankle Co-Contraction in Older Adults during Standing Balance

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7305
Author(s):  
Rachel V. Vitali ◽  
Vincent J. Barone ◽  
Jamie Ferris ◽  
Leia A. Stirling ◽  
Kathleen H. Sienko
Keyword(s):  
Older Adults ◽  
Visual Feedback ◽  
Surface Electromyography ◽  
Preliminary Investigation ◽  
Balance Training ◽  
Standing Balance ◽  
Medial Gastrocnemius ◽  
Feedback Type ◽  
Balance Task ◽  
Muscle Pair

This preliminary investigation studied the effects of concurrent and terminal visual feedback during a standing balance task on ankle co-contraction, which was accomplished via surface electromyography of an agonist–antagonist muscle pair (medial gastrocnemius and tibialis anterior muscles). Two complementary mathematical definitions of co-contraction indices captured changes in ankle muscle recruitment and modulation strategies. Nineteen healthy older adults received both feedback types in a randomized order. Following an analysis of co-contraction index reliability as a function of surface electromyography normalization technique, linear mixed-effects regression analyses revealed participants learned or utilized different ankle co-contraction recruitment (i.e., relative muscle pair activity magnitudes) and modulation (i.e., absolute muscle pair activity magnitudes) strategies depending on feedback type and following the cessation of feedback use. Ankle co-contraction modulation increased when concurrent feedback was used and significantly decreased when concurrent feedback was removed. Ankle co-contraction recruitment and modulation did not significantly change when terminal feedback was used or when it was removed. Neither ankle co-contraction recruitment nor modulation was significantly different when concurrent feedback was used compared to when terminal feedback was used. The changes in ankle co-contraction recruitment and modulation were significantly different when concurrent feedback was removed as compared to when terminal feedback was removed. Finally, this study found a significant interaction between feedback type, removal of feedback, and order of use of feedback type. These results have implications for the design of balance training technologies using visual feedback.

Evidence that a disordered servo-like mechanism contributes to tremor in movements during cerebellar dysfunction

1986 ◽  
Vol 56 (1) ◽  
pp. 123-136 ◽  
Author(s):  
J. Hore ◽  
D. Flament
Keyword(s):  
Visual Feedback ◽  
Initial Velocity ◽  
Cerebellar Nuclei ◽  
Emg Activity ◽  
Constant Force ◽  
Inverse Relation ◽  
Cerebellar Dysfunction ◽  
Antagonist Activity ◽  
Initial Decrease ◽  
Cebus Monkeys

The characteristics of discontinuities and tremor that occurred in elbow flexions during cooling of the lateral cerebellar nuclei were investigated in five Cebus monkeys. Discontinuities in movements appeared as rhythmical oscillations (kinetic tremor) when movements were slow or when movements were made with a constant force that loaded the antagonist. These oscillations had similar properties to cerebellar terminal tremor following movements; e.g., their amplitude and frequency were decreased by addition of mass to the handle and they occurred in the absence of visual feedback. The abnormal initial decrease in velocity that initiated oscillations in flexion movements was associated with abnormally early or large antagonist (triceps) electromyogram (EMG) activity. This abnormal EMG activity did not follow the normal inverse relation between initial velocity and antagonist latency from onset of movement. The initial deflection from the expected trajectory was opposed by a second burst of EMG activity in the agonist (biceps). This second burst was not the continuation of a step of EMG activity because its amplitude was often larger than the amplitude of the first agonist burst. The second agonist burst had the properties of a servo-like response: it occurred when biceps shortening was slowed (but biceps was not stretched), its magnitude was proportional to the magnitude or the deflection in velocity, its latency was 50-80 ms from onset of the abnormal decrease in velocity, and it occurred in the absence of visual feedback. However, this servo-like response was disordered because it did not return the limb accurately to the expected trajectory. The servo-like mechanism was studied further by applying torque pulse perturbations during elbow flexions. When the cerebellar nuclei were cooled, agonist responses to the perturbation were proportional to the size of the velocity deflection, but they were prolonged and onset of antagonist activity was delayed. It is suggested that discontinuities and tremor in movements during cerebellar dysfunction result from the same mechanism: alternation between disordered stretch reflexes and disordered servo-assistance mechanisms, both partly involving transcortical pathways.

scholarly journals Balance task difficulty affects postural sway and cortical activity in healthy adolescents

2020 ◽  
Vol 238 (5) ◽  
pp. 1323-1333 ◽  
Author(s):  
Arnd Gebel ◽  
Tim Lehmann ◽  
Urs Granacher
Keyword(s):  
Power Spectrum ◽  
Task Difficulty ◽  
Postural Sway ◽  
Cortical Activity ◽  
Theta Band ◽  
Brain Areas ◽  
Frequency Bands ◽  
Band Power ◽  
Balance Task ◽  
Theta Band Power

Abstract Electroencephalographic (EEG) research indicates changes in adults’ low frequency bands of frontoparietal brain areas executing different balance tasks with increasing postural demands. However, this issue is unsolved for adolescents when performing the same balance task with increasing difficulty. Therefore, we examined the effects of a progressively increasing balance task difficulty on balance performance and brain activity in adolescents. Thirteen healthy adolescents aged 16–17 year performed tests in bipedal upright stance on a balance board with six progressively increasing levels of task difficulty. Postural sway and cortical activity were recorded simultaneously using a pressure sensitive measuring system and EEG. The power spectrum was analyzed for theta (4–7 Hz) and alpha-2 (10–12 Hz) frequency bands in pre-defined frontal, central, and parietal clusters of electrocortical sources. Repeated measures analysis of variance (rmANOVA) showed a significant main effect of task difficulty for postural sway (p < 0.001; d = 6.36). Concomitantly, the power spectrum changed in frontal, bilateral central, and bilateral parietal clusters. RmANOVAs revealed significant main effects of task difficulty for theta band power in the frontal (p < 0.001, d = 1.80) and both central clusters (left: p < 0.001, d = 1.49; right: p < 0.001, d = 1.42) as well as for alpha-2 band power in both parietal clusters (left: p < 0.001, d = 1.39; right: p < 0.001, d = 1.05) and in the central right cluster (p = 0.005, d = 0.92). Increases in theta band power (frontal, central) and decreases in alpha-2 power (central, parietal) with increasing balance task difficulty may reflect increased attentional processes and/or error monitoring as well as increased sensory information processing due to increasing postural demands. In general, our findings are mostly in agreement with studies conducted in adults. Similar to adult studies, our data with adolescents indicated the involvement of frontoparietal brain areas in the regulation of postural control. In addition, we detected that activity of selected brain areas (e.g., bilateral central) changed with increasing postural demands.

An Older Adult Study of Concurrent Visual Feedback in Learning Continuous Balance

2018 ◽  
Vol 125 (6) ◽  
pp. 1160-1172 ◽  
Author(s):  
Jeff E. Goodwin ◽  
Noreen L. Goggin
Keyword(s):  
Older Adults ◽  
Older Adult ◽  
Visual Feedback ◽  
Knowledge Of Results ◽  
Adult Study ◽  
Retention Testing ◽  
Balance Task ◽  
Guidance Theory ◽  
Circular Platform ◽  
Anterior Posterior

This investigation manipulated concurrent visual feedback for older adults learning to perform a continuous balance task. We randomly assigned 21 older adults to one of three knowledge of results (KR) groups with varying concurrent but always 100% terminal feedback percentages during acquisition: 100% Concurrent and Terminal (100% C&T), 50% Concurrent and 100% Terminal (50% C & 100% T), and 0% Concurrent and 100% Terminal (0% C & 100% T). The continuous balance task involved learning to maintain balance on a circular platform that moved simultaneously on both anterior/posterior and medial/lateral axes. We tested participants before acquisition phase learning and two days afterwards (retention test). At retention testing, participants in the 50% C & 100% T and those in the 0% C & 100% T conditions demonstrated significantly greater accuracy and stability than did participants in the 100% C&T condition. These findings extend previous research with young adults in supporting the guidance theory that too frequent a provision of concurrent knowledge of results negatively affects learning.

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