Search results for "voluntary movement"
showing 9 items of 9 documents
Visually produced locomotion in an autokinetic setup.
1987
On individual ttials, 15 subjects stood G m before a minicomputer screen displaying a colon in a completely darkened room Subjects were aware that the light source wzs stationary. They were instructed to fixate the colon and to perform nonlocomotive jogging in place for 2 min. and continuously to report their sensations. Room lights were turned on after 30 sec., and subjects' deviations from their starting places were measured. All subjects had moved toward the light source (M = 4.42 m, SD = .43) although they were convinced that they had not moved. Instead, they had reported either the light source approached them or the light source became larger and/or more intense. On a second trial, su…
Gabapentin in the treatment of hemifacial spasm
2001
Objectives To evaluate the efficacy of gabapentin in the treatment of hemifacial spasm. Material and methods Twenty-three patients with hemifacial spasm not suitable for surgery or therapy with botulinum toxin were treated with gabapentin. The main efficacy parameter was the percentage of spasm reduction. Results A clinically significant reduction of spasms was obtained by 16 patients. Conclusion Gabapentin was effective and safe in reducing hemifacial spasm in 16 out 23 (69.6%) patients.
Acoustic rhinometry in pre-school children.
1993
Acoustic rhinometry was performed in 35 normal nose-breathing children between 3 and 6 years. The average cross-sectional areas at the nasal valve, at the anterior end of the turbinates, and in the nasopharynx were 0.34 +/- 0.06 cm2, 0.35 +/- 0.08 cm2 and 1.37 +/- 0.48 cm2 respectively. The average minimal cross-sectional area was 0.29 +/- 0.06 cm2. The minimal cross-sectional area was located at the nasal valve in 14 and at the anterior end of nasal turbinates in 21 of the 35 children. As would be expected, the cross-sectional areas at different sites of the nasal cavity increased with increasing age of the children. But, whereas the minimal cross-sectional area increased by 0.024 cm2 per …
Anticipatory Postural Adjustments and kinematic arm features when postural stability is manipulated
2018
International audience; Beyond the classical paradigm that presents the Anticipatory Postural Adjustments (APAs) as a manner to create forces that counteract disturbances arising from the moving segment during a pointing task, there is a controversial discussion about the role APAs to facilitate the movement and perform a task accurately. In addition, arm kinematics features are classically used to infer the content of motor planning for the execution and the control of arm movements, The present study aimed to disentangle the conflicting role of APAs during an arm-pointing task in which the subjects reach a central diode that suddenly turns on, while their postural stability was manipulate…
''Modulation of Anticipatory Postural Activity For Multiple Conditions of A Whole-body Pointing Task''
2012
Tolambiya, A. | Chiovetto, E. | Pozzo, T. | Thomas, E.; International audience; ''This is a study on associated postural activities during the anticipatory segments of a multijoint movement. Several previous studies have shown that they are task dependant. The previous studies, however, have mostly been limited in demonstrating the presence of modulation for one task condition, that is, one aspect such as the distance of the target or the direction of reaching. Real-life activities like whole-body pointing, however, can vary in several ways. How specific is the adaptation of the postural activities for the diverse possibilities of a whole-body pointing task? We used a classification paradig…
Interhemispheric inhibition is dynamically regulated during action observation
2016
International audience; It is now well established that the motor system plays a pivotal role in action observation and that the neurophysiological processes underlying perception and action overlaps. However, while various experiments have shown a specific facilitation of the contralateral motor cortex during action observation, no information is available concerning the dynamics of interhemispheric interactions. The aim of the present study was, therefore, to assess interhemispheric inhibition during the observation of others' actions. We designed a transcranial magnetic stimulation (TMS) experiment in which we measured both corticospinal excitability and interhemispheric inhibition, this…
Posterior variant of alien limb syndrome with sudden clinical onset as self-hitting associated with thalamic stroke
2020
We present a case of sudden postischaemic onset of alien limb syndrome, with unintentional self-injury. Alien limb syndrome is an uncommon neurological disorder featured by uncontrolled and involuntary movements of a limb. Three variants of alien limb syndrome have been described: the anterior, featured by grasping of surrounding objects, the callosal, presenting with intermanual conflict, and the posterior, associated with involuntary levitation of the limb. Our patient suffered from an acute presentation of the posterior variant of the alien limb syndrome, resulting from an isolated thalamic stroke which was documented using 24-h computed tomography brain scan. Only one previous case of a…
Motor action execution in reaction-time movements : Magnetoencephalographic study
2019
OBJECTIVE: Reaction-time movements are internally planned in the brain. Presumably, proactive control in reaction-time movements appears as an inhibitory phase preceding movement execution. We identified the brain activity of reaction-time movements in close proximity to movement onset and compared it with similar self-paced voluntary movements without external command. DESIGN: We recorded 18 healthy participants performing reaction-time and self-paced fast index finger abductions with 306-sensor magnetoencephalography and electromyography. Reaction-time movements were performed as responses to cutaneous electrical stimulation delivered on the hand radial nerve area. Motor field and movemen…
Plantar flexor activation capacity and H reflex in older adults: adaptations to strength training.
2002
The purpose of this study was to investigate whether the voluntary neural drive and the excitability of the reflex arc could be modulated by training, even in old age. To this aim, the effects of a 16-wk strengthening program on plantar flexor voluntary activation (VA) and on the maximum Hoffman reflex (Hmax)-to-maximum M wave (Mmax) ratio were investigated in 14 elderly men (65–80 yr). After training, isometric maximum voluntary contraction (MVC) increased by 18% ( P < 0.05) and weight-lifting ability by 24% ( P < 0.001). Twitch contraction time decreased by 8% ( P < 0.01), but no changes in half relaxation time and in peak twitch torque were observed. The VA, assessed by twitch …