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Trunk isometric force production parameters during erector spinae muscle vibration at different frequencies.

Boucher JA, Normand MC, Descarreaux M - J Neuroeng Rehabil (2013)

Bottom Line: The control of force and its variability are often considered determinants of motor performance and neuromuscular control.The main finding suggests that erector spinae muscle vibration significantly decreases the accuracy in a trunk extension isometric force reproduction task.The results suggest that acute erector spinae muscle vibration interferes with torque generation sequence of the trunk by distorting proprioceptive information in healthy participants.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: Vibration is known to alter proprioceptive afferents and create a tonic vibration reflex. The control of force and its variability are often considered determinants of motor performance and neuromuscular control. However, the effect of vibration on paraspinal muscle control and force production remains to be determined.

Methods: Twenty-one healthy adults were asked to perform isometric trunk flexion and extension torque at 60% of their maximal voluntary isometric contraction, under three different vibration conditions: no vibration, vibration frequencies of 30 Hz and 80 Hz. Eighteen isometric contractions were performed under each condition without any feedback. Mechanical vibrations were applied bilaterally over the lumbar erector spinae muscles while participants were in neutral standing position. Time to peak torque (TPT), variable error (VE) as well as constant error (CE) and absolute error (AE) in peak torque were calculated and compared between conditions.

Results: The main finding suggests that erector spinae muscle vibration significantly decreases the accuracy in a trunk extension isometric force reproduction task. There was no difference between both vibration frequencies with regard to force production parameters. Antagonist muscles do not seem to be directly affected by vibration stimulation when performing a trunk isometric task.

Conclusions: The results suggest that acute erector spinae muscle vibration interferes with torque generation sequence of the trunk by distorting proprioceptive information in healthy participants.

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Testing position in neutral standing posture with and without mechanical vibration.
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Figure 1: Testing position in neutral standing posture with and without mechanical vibration.

Mentions: Testing was performed in a neutral standing posture (no trunk flexion or extension) with the set-up shown in Figure 1. Force data (torque) was obtained from an isokinetic device (The LIDO Active, Loredan Biomedical, West Sacramento, USA) used only in the isometric testing mode. First, maximal isometric flexion and extension torques of trunk muscles were collected while participants received personal encouragements from the experimenters. The higher torque value obtained in two consecutive 4-seconds trials was used as the reference for maximal voluntary contraction (MVC). After establishing the MVC, participants were instructed to produce a sub-maximal trunk isometric force as quickly as possible as a warm-up procedure for each condition (flexion and extension). For the learning phase, they were told to produce a single impulse ("shoot and release") and to make no attempt at correcting the force once the contraction was initiated. During this phase, participants were given visual accuracy feedback through an oscilloscope located in front of them. They were able to evaluate their performance and correct it for the next trial, if necessary. Participants were specifically asked to produce peak torques that were within 10% of the target goal set at 60% of their MVC, while keeping their eyes open for the entire session. The learning phase, completed without any form of vibration, was stopped when ten contractions were performed. This procedure was used to ensure that all participants understood and adequately performed the experimental task. For every trial, torque data were recorded at a sampling frequency of 100 Hz. They were digitally filtered with an eighth-order Butterworth filter (10 Hz low-pass cut-off frequency).


Trunk isometric force production parameters during erector spinae muscle vibration at different frequencies.

Boucher JA, Normand MC, Descarreaux M - J Neuroeng Rehabil (2013)

Testing position in neutral standing posture with and without mechanical vibration.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750832&req=5

Figure 1: Testing position in neutral standing posture with and without mechanical vibration.
Mentions: Testing was performed in a neutral standing posture (no trunk flexion or extension) with the set-up shown in Figure 1. Force data (torque) was obtained from an isokinetic device (The LIDO Active, Loredan Biomedical, West Sacramento, USA) used only in the isometric testing mode. First, maximal isometric flexion and extension torques of trunk muscles were collected while participants received personal encouragements from the experimenters. The higher torque value obtained in two consecutive 4-seconds trials was used as the reference for maximal voluntary contraction (MVC). After establishing the MVC, participants were instructed to produce a sub-maximal trunk isometric force as quickly as possible as a warm-up procedure for each condition (flexion and extension). For the learning phase, they were told to produce a single impulse ("shoot and release") and to make no attempt at correcting the force once the contraction was initiated. During this phase, participants were given visual accuracy feedback through an oscilloscope located in front of them. They were able to evaluate their performance and correct it for the next trial, if necessary. Participants were specifically asked to produce peak torques that were within 10% of the target goal set at 60% of their MVC, while keeping their eyes open for the entire session. The learning phase, completed without any form of vibration, was stopped when ten contractions were performed. This procedure was used to ensure that all participants understood and adequately performed the experimental task. For every trial, torque data were recorded at a sampling frequency of 100 Hz. They were digitally filtered with an eighth-order Butterworth filter (10 Hz low-pass cut-off frequency).

Bottom Line: The control of force and its variability are often considered determinants of motor performance and neuromuscular control.The main finding suggests that erector spinae muscle vibration significantly decreases the accuracy in a trunk extension isometric force reproduction task.The results suggest that acute erector spinae muscle vibration interferes with torque generation sequence of the trunk by distorting proprioceptive information in healthy participants.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: Vibration is known to alter proprioceptive afferents and create a tonic vibration reflex. The control of force and its variability are often considered determinants of motor performance and neuromuscular control. However, the effect of vibration on paraspinal muscle control and force production remains to be determined.

Methods: Twenty-one healthy adults were asked to perform isometric trunk flexion and extension torque at 60% of their maximal voluntary isometric contraction, under three different vibration conditions: no vibration, vibration frequencies of 30 Hz and 80 Hz. Eighteen isometric contractions were performed under each condition without any feedback. Mechanical vibrations were applied bilaterally over the lumbar erector spinae muscles while participants were in neutral standing position. Time to peak torque (TPT), variable error (VE) as well as constant error (CE) and absolute error (AE) in peak torque were calculated and compared between conditions.

Results: The main finding suggests that erector spinae muscle vibration significantly decreases the accuracy in a trunk extension isometric force reproduction task. There was no difference between both vibration frequencies with regard to force production parameters. Antagonist muscles do not seem to be directly affected by vibration stimulation when performing a trunk isometric task.

Conclusions: The results suggest that acute erector spinae muscle vibration interferes with torque generation sequence of the trunk by distorting proprioceptive information in healthy participants.

Show MeSH
Related in: MedlinePlus