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"Voluntary stepping"

Marco Schieppati, S Sozzi, O Crisafulli
OBJECTIVE: Turning around while stepping in place can be produced voluntarily. One way of producing involuntary turning around while stepping-in-place eyes closed is by training subjects onto a rotating platform while stepping-in-place and maintaining a fixed body orientation in space. This task produces a post-effect called "podokinetic after-rotation" (PKAR). Such training has been suggested for Parkinsonian patients. We tested the hypothesis that voluntary stepping-in-place and turning around also produces a post-effect similar to the PKAR...
September 2016: Annals of Physical and Rehabilitation Medicine
Yeshayahu Hutzler, Olga Korsensky, Yocheved Laufer
BACKGROUND: Rapid voluntary stepping has been recognized as an important measure of balance control. OBJECTIVE: The purpose of this study was to assess the feasibility and convergent validity of a Rapid Stepping Test protocol utilizing a virtual reality SeeMeTM system (VR-RST) in elderly ambulatory and independent individuals living in a community residential home. METHODS: Associations between step execution times determined by the system and the Activities-specific Balance Confidence (ABC) Questionnaire, and clinical measures of balance performance in the MiniBESTest and Timed Up and Go (TUG) test, were established in 60 participants (mean age 88...
August 29, 2016: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
Yury Gerasimenko, Parag Gad, Dimitry Sayenko, Zach McKinney, Ruslan Gorodnichev, Aleksandr Puhov, Tatiana Moshonkina, Aleksandr Savochin, Victor Selionov, Tatiana Shigueva, Elena Tomilovskaya, Inessa Kozlovskaya, V Reggie Edgerton
We reported previously that both transcutaneous electrical spinal cord stimulation and direct pressure stimulation of the plantar surfaces of the feet can elicit rhythmic involuntary step-like movements in noninjured subjects with their legs in a gravity-neutral apparatus. The present experiments investigated the convergence of spinal and plantar pressure stimulation and voluntary effort in the activation of locomotor movements in uninjured subjects under full body weight support in a vertical position. For all conditions, leg movements were analyzed using electromyographic (EMG) recordings and optical motion capture of joint kinematics...
July 1, 2016: Journal of Neurophysiology
Ilan Kurz, Yoav Gimmon, Amir Shapiro, Ronen Debi, Yoram Snir, Itshak Melzer
BACKGROUND: Falls are common among elderly, most of them occur while slipping or tripping during walking. We aimed to explore whether a training program that incorporates unexpected loss of balance during walking able to improve risk factors for falls. METHODS: In a double-blind randomized controlled trial 53 community dwelling older adults (age 80.1±5.6 years), were recruited and randomly allocated to an intervention group (n = 27) or a control group (n = 26)...
2016: BMC Geriatrics
Mark W Rogers, Marie-Laure Mille
Physiological and degenerative changes affecting human standing balance are major contributors to falls with ageing. During imbalance, stepping is a powerful protective action for preserving balance that may be voluntarily initiated in recognition of a balance threat, or be induced by an externally imposed mechanical or sensory perturbation. Paradoxically, with ageing and falls, initiation slowing of voluntary stepping is observed together with perturbation-induced steps that are triggered as fast as or faster than for younger adults...
August 15, 2016: Journal of Physiology
Ruopeng Sun, John B Shea
The present study investigated the attention allocation during reactive stepping using a continuous finger-tapping task. Ten healthy young subjects were recruited to participate in this study. Subjects were required to perform a rapid voluntary step with either left or right leg after hearing an auditory tone while tapping their right index finger on a handhold numeric keypad. Step initiation conditions included simple and choice reaction forward stepping with three variants of continuous tapping task that were: (1) single task--no concurrent finger-tapping task; (2) dual task easy--one-button tapping task; (3) dual task hard--four-button tapping task...
April 2016: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Daniel S Peterson, Laurie A King, Rajal G Cohen, Fay B Horak
People with Parkinson disease (PD) who show freezing of gait also have dysfunction in cognitive domains that interact with mobility. Specifically, freezing of gait is associated with executive dysfunction involving response inhibition, divided attention or switching attention, and visuospatial function. The neural control impairments leading to freezing of gait have recently been attributed to higher-level, executive and attentional cortical processes involved in coordinating posture and gait rather than to lower-level, sensorimotor impairments...
May 2016: Physical Therapy
Jonathan C Singer, William E McIlroy, Stephen D Prentice
Research examining age-related changes in dynamic stability during stepping has recognised the importance of the restabilisation phase, subsequent to foot-contact. While regulation of the net ground reaction force (GRFnet) line of action is believed to influence dynamic stability during steady-state locomotion, such control during restabilisation remains unknown. This work explored the origins of age-related decline in mediolateral dynamic stability by examining the line of action of GRFnet relative to the centre of mass (COM) during restabilisation following voluntary stepping...
November 7, 2014: Journal of Biomechanics
I A Solopova, V A Selionov, O V Kazennikov, Y P Ivanenko
Here, we compared motor evoked potentials (MEP) in response to transcranial magnetic stimulation of the motor cortex and the H-reflex during voluntary and vibration-induced air-stepping movements in humans. Both the MEPs (in mm biceps femoris, rectus femoris and tibialis anterior) and H-reflex (in m soleus) were significantly smaller during vibration-induced cyclic leg movements at matched amplitudes of angular motion and muscle activity. These findings highlight differences between voluntary and non-voluntary activation of the spinal pattern generator circuitry in humans, presumably due to an extra facilitatory effect of voluntary control/triggering of stepping on spinal motoneurons and interneurons...
September 5, 2014: Neuroscience Letters
Pei-Yun Lee, Kris Gadareh, Adolfo M Bronstein
OBJECTIVES: Protective steps are essential for fall avoidance. Most studies only examined forwards stepping despite considerable bio-mechanical and visual differences between the forwards and backwards directions. We assess forward-backward differences in protective steps in a young and elderly group. METHODS: Protective stepping responses were elicited by a platform moving unpredictably either forwards or backwards. For control purposes, voluntary steps, in response to vibration cues on the forehead or occiput were also recorded...
April 2014: Human Movement Science
Katherine M Martinez, Marie-Laure Mille, Yunhui Zhang, Mark W Rogers
OBJECTIVES: To examine the stepping performance during voluntary and waist-pull perturbation-induced step initiation in people with chronic stroke. DESIGN: Repeated-measures single-case design. SETTING: University-based research laboratory. PARTICIPANTS: Community-dwelling stroke survivors (N=10). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Ground reaction forces and kinematic data were recorded to assess anticipatory postural adjustments (APAs) and step characteristics for both voluntary and induced stepping conditions...
December 2013: Archives of Physical Medicine and Rehabilitation
Ilan Kurz, Elinor Berezowski, Itshak Melzer
BACKGROUND: Quick step execution may prevent falls when balance is lost. Lateral steps often emerge as a consequence of frontal plane instability arising after the first rapid step. In this study, we suggest a new analysis, focusing on the variability of the frontal plane fluctuations of center of pressure (CoP), that is, mediolateral instability, and their changes over time during and immediately following rapid voluntary stepping in older and younger adults in single- and dual-task conditions...
November 2013: Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
Anahid H Saradjian, Luc Tremblay, Joy Perrier, Jean Blouin, Laurence Mouchnino
Several studies have shown that the transmission of afferent inputs from the periphery to the somatosensory cortex is attenuated during the preparation of voluntary movements. In the present study, we tested whether sensory attenuation is also observed during the preparation of a voluntary step. It would appear dysfunctional to suppress somatosensory information, which is considered to be of the utmost importance for gait preparation. In this context, we predict that the somatosensory information is facilitated during gait preparation...
July 2013: Journal of Neurophysiology
V A Selionov, I A Solopova, D S Zhvansky, A V Karabanov, L A Chernikova, V S Gurfinkel, Y P Ivanenko
The majority of research and therapeutic actions in Parkinson's disease (PD) focus on the encephalic areas, however, the potential involvement of the spinal cord in its genesis has received little attention. Here we examined spinal locomotor circuitry activation in patients with PD using various types of central and peripheral tonic stimulation and compared results to those of age-matched controls. Subjects lay on their sides with both legs suspended, allowing low-friction horizontal rotation of the limb joints...
April 3, 2013: Neuroscience
Patrick J Sparto, Susan I Fuhrman, Mark S Redfern, J Richard Jennings, Subashan Perera, Robert D Nebes, Joseph M Furman
Postural dual-task studies have demonstrated effects of various executive function components on gait and postural control in older adults. The purpose of the study was to explore the role of inhibition during lateral step initiation. Forty older adults participated (range 70-94 yr). Subjects stepped to the left or right in response to congruous and incongruous visual cues that consisted of left and right arrows appearing on left or right sides of a monitor. The timing of postural adjustments was identified by inflection points in the vertical ground reaction forces (VGRF) measured separately under each foot...
January 2013: Journal of Neurophysiology
Laura Rocchi, Patricia Carlson-Kuhta, Lorenzo Chiari, Kim J Burchiel, Penelope Hogarth, Fay B Horak
OBJECT: Difficulty with step initiation, called "start hesitation," is related to gait bradykinesia and is an early hallmark of gait freezing in Parkinson disease (PD). Authors of this study investigated the effects of deep brain stimulation (DBS) and levodopa on step initiation before and 6 months after DBS surgery in 29 patients with PD who were randomized to either the bilateral subthalamic nucleus (STN) or globus pallidus internus (GPi) as the DBS site. METHODS: The authors measured the amplitude and duration of anticipatory postural adjustments (APAs), the feed-forward postural preparation that precedes the onset of voluntary step initiation, based on center-of-pressure displacements on a force plate...
December 2012: Journal of Neurosurgery
Ori Elbar, Irit Tzedek, Elisha Vered, Gali Shvarth, Michael Friger, Itshak Melzer
This study evaluated the effects of a water exercise training program that includes perturbation exercises (WEP) to improve the speed of voluntary stepping reaction in older adults. Speed of voluntary stepping considered as an important skill to prevent a fall when balance is lost. In a single-blinded randomized controlled trial with a crossover design thirty-six independent old adults (64-88 years old) were divided into two groups. Group A received WEP for the first 12 weeks, followed by no intervention for the second 12 weeks...
January 2013: Archives of Gerontology and Geriatrics
Giuseppe Pichierri, Amos Coppe, Silvio Lorenzetti, Kurt Murer, Eling D de Bruin
BACKGROUND: This randomized controlled pilot study aimed to explore whether a cognitive-motor exercise program that combines traditional physical exercise with dance video gaming can improve the voluntary stepping responses of older adults under attention demanding dual task conditions. METHODS: Elderly subjects received twice weekly cognitive-motor exercise that included progressive strength and balance training supplemented by dance video gaming for 12 weeks (intervention group)...
2012: Clinical Interventions in Aging
Itshak Melzer, Lars Ie Oddsson
OBJECTIVES: To evaluate the effect of a group-based functional and specific balance training programme that included dual-task exercises on balance function in healthy older adults. DESIGN: A single-blind randomized controlled trial. SETTING: General community. PARTICIPANTS: Sixty-six community-dwelling older adults (age 77.0 ± 6.5 years), without functional balance impairment were recruited and allocated at random to an intervention group (n = 33) or a reference group (n = 33)...
March 2013: Clinical Rehabilitation
I A Solopova, V A Selionov
In healthy human the excitability of spinal alpha-motoneurons under application of vibrostimulation (20-60 Hz) to different leg muscles was investigated both in stationary condition and during stepping movements caused by vibration in the condition of suspended leg. In 15 subjects the amplitude of H-reflex were compared under vibration of rectus femoris (RF) and biceps femoris (BF) muscles of left leg as well during vibration of rectus femoris of contralateral, motionless leg in three spatial positions: upright, supine and on right side of body with suspended left leg...
March 2012: Fiziologiia Cheloveka
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