Magnified visual feedback exacerbates positional variability in older adults due to altered modulation of the primary agonist muscle

Baweja, Harsimran S.; Kwon, Min-hyuk; Christou, Evangelos A.

doi:10.1007/s00221-012-3219-0

Cited by 18 publications

(5 citation statements)

References 34 publications

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“…However, this occurs with access to visual feedback during the experiments and/or when teeth within the arch are splinted together. Similar influence of visual feedback on muscle recruitment patterns has been demonstrated in spinal and appendicular muscles . In contrast, within muscle heterogeneity during jaw loading does not occur when subjects are without visual feedback and when teeth are not splinted together .…”

Section: Discussionsupporting

confidence: 62%

Modeling of muscle forces in humans with and without temporomandibular joint disorders

Iwasaki

Liu

Gonzalez

et al. 2015

Orthod Craniofacial Res

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Objectives Subjects with/without temporomandibular joint disorders (TMJD) were tested for differences in muscle forces. Setting and Sample Population School of Dental Medicine, University at Buffalo. Ninety-one subjects were classified in 4 groups based on presence/absence (+/-) of chronic myofascial and/or TMJ pain (P) and bilateral disc displacement (DD). Material & Methods Validated numerical models employed an organizational objective and subjects’ anatomy to calculate masticatory muscle forces during static biting. ANOVA and Holm step-down procedure post-hoc tests assessed group differences. Theoretical geometries, representing the range of subjects’ muscle orientations, were surveyed via numerical models to identify key combinations resulting in high muscle forces. Effect-size (Cohen’s d) and ANOVA/post-hoc tests assessed group differences in key muscle orientations. Results +P-DD subjects had significantly higher muscle forces, especially for lateral pterygoid muscles, compared to the other groups (P<0.01) for bite-forces that were directed posteromedially or posterolaterally on mandibular molars and posteriorly and slightly medially on mandibular incisors. Key muscle orientations for peak lateral pterygoid muscle forces were identified and group comparisons showed mean orientation in +P-DD compared to other diagnostic groups was ≥5° more upright for masseter and ≥3° more posteriorly-directed for temporalis muscles (all Cohen’s d ≥0.8). Conclusion Predicted lateral pterygoid muscle forces were significantly higher in +P-DD compared to other groups for specific biting conditions and were attributable, in part, to differences in masseter and temporalis muscle orientations.

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Section: Discussionsupporting

confidence: 62%

Modeling of muscle forces in humans with and without temporomandibular joint disorders

Iwasaki

Liu

Gonzalez

et al. 2015

Orthod Craniofacial Res

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“…Abduction force is produced almost exclusively by the contraction of the first dorsal interosseus (FDI) muscle [13] , [14] . We used the left hand in this study for two reasons: 1) it makes the task more novel to the subjects because the left hand is the non-dominant hand [10] , [15] ; 2) to compare the findings of this study with previous studies [16] , [17] , [18] , [19] .…”

Section: Methodsmentioning

confidence: 99%

“…The EMG signal was sampled at 1 kHz with a Power 1401 A/D board (Cambridge Electronic Design, UK) and a NI-DAQ card (Model USB6251, National Instruments, Austin, TX, USA). The EMG signal was amplified (×1,000) and [7] , [15] high-pass filtered at 4 Hz (Bagnoli-16 Main Amplifier Unit, Delsys, Boston, MA, USA) and low-pass filtered at 500 Hz. EMG data were stored on a personal computer.…”

Section: Methodsmentioning

confidence: 99%

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Force Control Is Related to Low-Frequency Oscillations in Force and Surface EMG

et al. 2014

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Force variability during constant force tasks is directly related to oscillations below 0.5 Hz in force. However, it is unknown whether such oscillations exist in muscle activity. The purpose of this paper, therefore, was to determine whether oscillations below 0.5 Hz in force are evident in the activation of muscle. Fourteen young adults (21.07±2.76 years, 7 women) performed constant isometric force tasks at 5% and 30% MVC by abducting the left index finger. We recorded the force output from the index finger and surface EMG from the first dorsal interosseous (FDI) muscle and quantified the following outcomes: 1) variability of force using the SD of force; 2) power spectrum of force below 2 Hz; 3) EMG bursts; 4) power spectrum of EMG bursts below 2 Hz; and 5) power spectrum of the interference EMG from 10–300 Hz. The SD of force increased significantly from 5 to 30% MVC and this increase was significantly related to the increase in force oscillations below 0.5 Hz (R 2 = 0.82). For both force levels, the power spectrum for force and EMG burst was similar and contained most of the power from 0–0.5 Hz. Force and EMG burst oscillations below 0.5 Hz were highly coherent (coherence = 0.68). The increase in force oscillations below 0.5 Hz from 5 to 30% MVC was related to an increase in EMG burst oscillations below 0.5 Hz (R 2 = 0.51). Finally, there was a strong association between the increase in EMG burst oscillations below 0.5 Hz and the interference EMG from 35–60 Hz (R 2 = 0.95). In conclusion, this finding demonstrates that bursting of the EMG signal contains low-frequency oscillations below 0.5 Hz, which are associated with oscillations in force below 0.5 Hz.

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“…In addition, there is evidence to suggest that magnification of visual feedback changes the neural activation of muscle in older adults. For example, the age-associated impairments in force control with magnification of visual feedback were associated with lesser EMG power from 12 to 30 Hz in older adults (Baweja et al 2012), termed beta band by Hans Berger (Tudor et al 2005). More power within the beta band is viewed as antikinetic and is associated with less force variability (steadier) when the goal is to maintain a constant contraction (Engel and Fries 2010;Kristeva et al 2007;Witte et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Visual information processing in older adults: reaction time and motor unit pool modulation

Kwon

Christou

2018

Journal of Neurophysiology

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Currently, there is no evidence that magnification of visual feedback has motor implications beyond impairments in force control during a visuomotor task. We hypothesized that magnification of visual feedback would increase visual information processing, alter the muscle activation, and exacerbate the response time in older adults. To test this hypothesis, we examined whether magnification of visual feedback during a reaction time task alters the pre-motor time and the motor unit pool activation of older adults. Participants responded as fast as possible to a visual stimulus while they maintained a steady ankle dorsiflexion force (15% maximum) either with low-gain or high-gain visual feedback of force. We quantified the following: 1) response time and its components (pre-motor and motor time); 2) force variability; 3) motor unit pool activity of the tibialis anterior muscle. Older adults exhibited longer pre-motor time and greater force variability than young adults. Only in older adults, magnification of visual feedback lengthened the pre-motor time and exacerbated force variability. The slower pre-motor time in older adults with high-gain visual feedback was associated with increased force variability and an altered modulation of the motor unit pool. In conclusion, our findings provide novel evidence that magnification of visual feedback also exacerbates pre-motor time during a reaction time task in older adults, which is correlated with force variability and an altered modulation of motor unit pool. Thus, these findings suggest that visual information processing deficiencies in older adults could result in force control and reaction time impairments.

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Magnified visual feedback exacerbates positional variability in older adults due to altered modulation of the primary agonist muscle

Cited by 18 publications

References 34 publications

Modeling of muscle forces in humans with and without temporomandibular joint disorders

Modeling of muscle forces in humans with and without temporomandibular joint disorders

Force Control Is Related to Low-Frequency Oscillations in Force and Surface EMG

Visual information processing in older adults: reaction time and motor unit pool modulation

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