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Cohen, Steven L.; Richardson, Joseph V.; Klebez, J; Febbo, Stacy; Tucker, David I.

doi:10.1023/a:1011325519568

Cited by 12 publications

(1 citation statement)

References 17 publications

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“…That is, participants could evaluate the steepness of ascent for the torque-time curve. The constant sensorimotor integration of visual feedback would tend to drive progressive changes in the maximum rate of torque development as previously observed (Lai and Shea, 1999b;Cohen et al, 2001;Rosenkranz and Rothwell, 2012). In contrast, there was no feedback about variability of the torque-time profiles.…”

Section: Motor Learningmentioning

confidence: 54%

Effects of the Proprioceptive Neuromuscular Facilitation Contraction Sequence on Motor Skill Learning-Related Increases in the Maximal Rate of Wrist Flexion Torque Development

Green

McGuire

Gabriel

2021

Front. Hum. Neurosci.

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Background: The proprioceptive neuromuscular facilitation (PNF) reciprocal contraction pattern has the potential to increase the maximum rate of torque development. However, it is a more complex resistive exercise task and may interfere with improvements in the maximum rate of torque development due to motor skill learning, as observed for unidirectional contractions. The purpose of this study was to examine the cost-benefit of using the PNF exercise technique to increase the maximum rate of torque development.Methods: Twenty-six participants completed isometric maximal extension-to-flexion (experimental PNF group) or flexion-only (control group) contractions at the wrist. Ten of the assigned contractions were performed on each of three sessions separated by 48-h for skill acquisition. Retention was assessed with 5 contractions performed 2-weeks after acquisition. Torque and surface electromyographic (sEMG) activity were analyzed for evidence of facilitated contractions between groups, as well as alterations in muscle coordination assessed across test sessions. The criterion measures were: mean maximal isometric wrist flexion toque; the maximal rate of torque development (dτ/dtmax); root-mean-square error (RMSE) variability of the rate of torque versus torque phase-plane; the rate of wrist flexion muscle activation (Q30); a coactivation ratio for wrist flexor and extensor sEMG activity; and wrist flexor electromechanical delay (EMD).Results: There were no significant differences between groups with respect to maximal wrist flexion torque, dτ/dtmax or RMSE variability of torque trajectories. Both groups exhibited a progressive increase in maximal strength (+23.35% p < 0.01, η2 = 0.655) and in dτ/dtmax (+19.84% p = 0.08, η2 = 0.150) from the start of acquisition to retention. RMSE was lowest after a 2-week rest interval (−18.2% p = 0.04, η2 = 0.198). There were no significant differences between groups in the rate of muscle activation or the coactivation ratio. There was a reduction in coactivation that was retained after a 2-week rest interval (−32.60%, p = 0.02, η2 = 0.266). Alternatively, EMD was significantly greater in the experimental group (Δ 77.43%, p < 0.01, η2 = 0.809) across all sessions. However, both groups had a similar pattern of improvement to the third consecutive day of testing (−16.82%, p = 0.049, η2 = 0.189), but returned close to baseline value after the 2-week rest interval.Discussion: The wrist extension-to-flexion contraction pattern did not result in a greater maximal rate of torque development than simple contractions of the wrist flexors. There was no difference between groups with respect to motor skill learning. The main adaptation in neuromotor control was a decrease in coactivation, not the maximal rate of muscle activation.

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Section: Motor Learningmentioning

confidence: 54%

Effects of the Proprioceptive Neuromuscular Facilitation Contraction Sequence on Motor Skill Learning-Related Increases in the Maximal Rate of Wrist Flexion Torque Development

Green

McGuire

Gabriel

2021

Front. Hum. Neurosci.

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Surface EMG Biofeedback

Gallina

Gazzoni

Falla

et al. 2016

Surface Electromyography : Physiology, Engineering, and Applications

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The effects of massed versus distributed contractions on the variability of maximal isometric force

et al. 2014

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This study evaluated the effect of a massed versus distributed repetition schedule on the variability of force and surface electromyographic (sEMG) activity during maximal voluntary isometric elbow flexion contractions. The massed group (N = 13) performed 15 contractions on 1 day, while the distributed group (N = 13) performed 15 contractions across three consecutive days (five per day). Two retention tests (five contractions each) occurred 2 weeks and 3 months after the final trial of the initial test sessions. Force and sEMG of the biceps and triceps brachii muscles were recorded concurrently. Both groups had comparable increases in force and biceps brachii sEMG that continued over short- and longer-term retention tests (p < 0.05). Triceps brachii sEMG exhibited a more complicated pattern of successive decreases and increases (p < 0.05). The massed repetition schedule resulted in significantly (p < 0.05) less variability in maintaining a constant force [root mean square (RMS) error]. There was a significant decrease in the variability of the force-time and sEMG-time curves as assessed by the variance ratio (VR) (p < 0.05). Only biceps sEMG and VR correlated highly with force VR for the distributed group. Total (biceps + triceps) sEMG magnitude and variability correlated highly with both RMS error and force VR for the massed group. It was concluded that the massed contraction pattern allowed participants to learn how to regulate joint stiffness in addition to the variability of muscle activity. This allowed for greater decreases in RMS error than could be obtained by regulating the variability of muscle activity alone.

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Cited by 12 publications

References 17 publications

Effects of the Proprioceptive Neuromuscular Facilitation Contraction Sequence on Motor Skill Learning-Related Increases in the Maximal Rate of Wrist Flexion Torque Development

Effects of the Proprioceptive Neuromuscular Facilitation Contraction Sequence on Motor Skill Learning-Related Increases in the Maximal Rate of Wrist Flexion Torque Development

Surface EMG Biofeedback

The effects of massed versus distributed contractions on the variability of maximal isometric force

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