Immediate and remote postactivation effects in the human motor system

Gurfinkel, V. S.; Levik, Yu. S.; Lebedev, Mikhail

doi:10.1007/bf01058224

Cited by 28 publications

(53 citation statements)

References 6 publications

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“…According to a theory proposed by Gurfinkel et al, this light feeling is explained by the absence of voluntary effort, converse to the feeling of a heavy arm when the muscles are curarized [30]. In general, the experiences of voluntary action differ strongly from those of similar passive body movements.…”

Section: Discussionmentioning

confidence: 99%

“…In summary, the Kohnstamm generator is either a 'tonogenic' central network triggered by the peripheral inputs and/or effort signals, or it is a collection of central neurons that drive the involuntary movement based on persistent peripheral inputs [30]. What is important for this report is that long-lasting central motor outputs (cortical and/or spinal) undoubtedly drive the Kohnstamm movement and this permits new theoretical questions on how voluntary inhibitory commands interact with ongoing involuntary motor outputs.…”

Section: Introductionmentioning

confidence: 99%

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Using voluntary motor commands to inhibit involuntary arm movements

2014

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A hallmark of voluntary motor control is the ability to stop an ongoing movement. Is voluntary motor inhibition a general neural mechanism that can be focused on any movement, including involuntary movements, or is it mere termination of a positive voluntary motor command? The involuntary arm lift, or 'floating arm trick', is a distinctive long-lasting reflex of the deltoid muscle. We investigated how a voluntary motor network inhibits this form of involuntary motor control. Transcranial magnetic stimulation of the motor cortex during the floating arm trick produced a silent period in the reflexively contracting deltoid muscle, followed by a rebound of muscle activity. This pattern suggests a persistent generator of involuntary motor commands. Instructions to bring the arm down voluntarily reduced activity of deltoid muscle. When this voluntary effort was withdrawn, the involuntary arm lift resumed. Further, voluntary motor inhibition produced a strange illusion of physical resistance to bringing the arm down, as if ongoing involuntarily generated commands were located in a 'sensory blind-spot', inaccessible to conscious perception. Our results suggest that voluntary motor inhibition may be a specific neural function, distinct from absence of positive voluntary motor commands.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Using voluntary motor commands to inhibit involuntary arm movements

2014

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“…the brain stem. According to Gurfinkel et al (7), the brain stem is the site of PAE generation (the so-called "tonogenic" center). The excitability of spinal gamma-motoneurons can be modulated by thermal stimulation of the hypothalamus through brain stem-spinal connections [6].…”

Section: Discussionmentioning

confidence: 99%

“…To evoke muscle tonus related to PAE the subjects were required to maintain prolonged steady voluntary isometric contraction (VIC), 70% of the maximal voluntary contraction, in the investigated muscle [7]. To obtain PAE in the brachial biceps muscles (BBs) subjects were instructed to conduct simultaneous flexion of both elbow joints against a fixed horizontal plate (desk) by the The analogue electromyographical (EMG) activity was bilaterally recorded with ME3000P device (MEGA Electronics Ltd, Kuopio, Finland) both in BBs and TBs.…”

Section: Evoking Pae and Electromyographic Parameters Of Paementioning

confidence: 99%

“…Meigal 1 1, 18]. Gurfinkel et al [7] regard the PALE as a result o f accumulation o f excitation, which comes with sensory inflow from the contracting muscle to a special so-called " t o n o g e n i c " centre. This centre, located in the brain stem and cerebellum, maintains partial contraction in the muscle for several minutes after termination of the v o l u n t a r y activity in the muscle.…”

Section: Introductionmentioning

confidence: 98%

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Influence of cold and hot conditions on postactivation in human skeletal muscles

Meigal

Lupandin

Hänninen

1996

Pflugers Arch - Eur J Physiol

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The influence of cold (+5 degrees C), room temperature (+22 degrees C) and hot (+75 degrees C) air exposures on postactivation effects (PAE) in brachial biceps (BBs) and triceps (TBs) muscles were investigated bilaterally in six male subjects. PAE were evoked by 1 min volitional isometric contraction (VIC) at submaximal level in BBs by holding an inertial weight by palms, with right-angled elbows. At room temperature, average EMG during PAE (PAEav) usually was 2-4% and the integral of EMG (PAEint) was 3-7% of that of VIC respectively. PEA duration was 1-6 min. Cold exposure evoked an approximately two-fold increase of PAEint (P < 0.01). Hot exposure decreased PAEint (P < 0.01) and shortened PAE duration by approximately 50% (P < 0.01). In two subjects, long- term modulation of EMG intensity during PAE was observed. Cold increased the frequency and amplitude of these waves, while heat decreased them. In two subjects, alternation of BBs and TBs in EMG activity during PAE was observed. The data obtained suggest that postactivation of muscles strongly depends on the environmental temperature.

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Long-lasting body leanings following neck muscle isometric contractions

et al. 2004

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Our objective was to investigate the neural mechanisms and the functional relevance of motor effects that develop involuntarily following the release of a sustained isometric muscle contraction. The few data available in the literature deal only with post-contractions occurring in a body segment. Although these data emphasise the role of proprioceptive input, the question as to whether this phenomenon is of central or peripheral origin remains unclear. Given the leading role of neck muscle proprioceptive input in body orientation and posture regulation, we designed two experiments to test for postural posteffects after voluntary and involuntary neck muscle contraction. The spatiotemporal characteristics of the posteffects were analysed by means of stabilometric recordings following 30-s isometric contraction of splenius, trapezius and levator muscle groups, and 30-s electrically-induced contraction of the levator muscle group. Results show that a postural response occurred after voluntary contraction of each muscle group tested, which was oriented in the plane of action of the muscle, and lasted 14 min at least. In contrast, no clearly oriented body leanings were found after electrical stimulation of the levator muscle, except for a slight increase in natural postural instability. Data are interpreted as a change in the postural reference resulting from an increase in proprioceptive inflow accompanying mainly the voluntary muscle contraction.

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Immediate and remote postactivation effects in the human motor system

Cited by 28 publications

References 6 publications

Using voluntary motor commands to inhibit involuntary arm movements

Using voluntary motor commands to inhibit involuntary arm movements

Influence of cold and hot conditions on postactivation in human skeletal muscles

Long-lasting body leanings following neck muscle isometric contractions

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