Cortical contributions to control of posture during unrestricted and restricted stance

2014 ◽  
Vol 111 (9) ◽  
pp. 1920-1926 ◽  
Author(s):  
Chantelle D. Murnaghan ◽  
Jordan W. Squair ◽  
Romeo Chua ◽  
J. Timothy Inglis ◽  
Mark G. Carpenter
Keyword(s):  
Muscle Activity ◽  
Critical Level ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Sensory Information ◽  
Upright Stance ◽  
Subcortical Structures ◽  
The Central Nervous System ◽  
The Relationship

There is very little consensus regarding the mechanisms underlying postural control. Whereas some theories suggest that posture is controlled at lower levels (i.e., brain stem and spinal cord), other theories have proposed that upright stance is controlled using higher centers, including the motor cortex. In the current investigation, we used corticomuscular coherence (CMC) to investigate the relationship between cortical and shank muscle activity during conditions of unrestricted and restricted postural sway. Participants were instructed to stand as still as possible in an apparatus that allowed the center of mass to move freely (“Unlocked”) or to be stabilized (“Locked”) without subject awareness. EEG (Cz) and electromyography (soleus and lateral/medial gastrocnemii) were collected and used to estimate CMC over the Unlocked and Locked periods. Confirming our previous results, increases in center of pressure (COP) displacements were observed in 9 of 12 participants in the Locked compared with Unlocked condition. Across these 9 participants, CMC was low or absent in both the Unlocked and Locked conditions. The results from the current study suggest that this increase is not associated with an increase in the relationship between cortical and shank muscle activities. Rather, it may be that increases in COP displacement with locking are mediated by subcortical structures as a means of increasing sway to provide the central nervous system with a critical level of sensory information.

Postural sway with earth-fixed and body-referenced finger contact in young and older adults

1999 ◽  
Vol 9 (2) ◽  
pp. 103-109
Author(s):  
Reginald L. Reginella ◽  
Mark S. Redfern ◽  
Joseph M. Furman
Keyword(s):  
Older Adults ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Sensory Information ◽  
Body Sway ◽  
Support Surface ◽  
Proprioceptive Information ◽  
Postural Control System ◽  
Fixed Reference ◽  
Older Subjects

Sensory information from lightly touching a reference with the hand is known to influence postural sway in young adults. The primary aim of this study was to compare the influence of finger contact (FC) with an earth-fixed reference to the influence of FC with a body-fixed reference. A second goal of this study was to determine if FC is used differently by older adults compared to younger adults. Using a force plate, center of pressure at the feet was recorded from blindfolded young and older subjects during several conditions. Subjects either did or did not lightly touch a force-sensitive plate that was either earth-fixed or moved forward and backward in synchrony with body sway (that is, sway-referenced). In addition, support surface conditions were also varied, including a fixed floor and a sway-referenced floor using an EquitestTM. Results showed that the type of FC, floor condition, and age each had an effect on postural sway. Touching an earth-fixed plate decreased postural sway as compared to no touching, while touching a sway-referenced plate incresased sway. This influence of FC was enhanced when the floor was sway-referenced. Although older subjects swayed more than young subjects overall, no age-FC interactions occurred, indicating that FC was not utilized differently between the age groups. This study suggests that FC cannot be disregarded as erroneous, especially when proprioceptive information from the legs is distorted. Further, FC is integrated with other sensory information by the postural control system similarly in young and older persons.

Position and Velocity Coupling of Postural Sway to Somatosensory Drive

1998 ◽  
Vol 79 (4) ◽  
pp. 1661-1674 ◽  
Author(s):  
John Jeka ◽  
Kelvin Oie ◽  
Gregor Schöner ◽  
Tjeerd Dijkstra ◽  
Elaine Henson
Keyword(s):  
Contact Surface ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Somatosensory System ◽  
Moving Frame ◽  
Body Sway ◽  
Driving Frequency ◽  
Moving Contact ◽  
Spatial Reference Frame

Jeka, John, Kelvin Oie, Gregor Schöner, Tjeerd Dijkstra, and Elaine Henson. Position and velocity coupling of postural sway to somatosensory drive. J. Neurophysiol. 79: 1661–1674, 1998. Light touch contact of a fingertip to a stationary surface provides orientation information that enhances control of upright stance. Slight changes in contact force at the fingertip lead to sensory cues about the direction of body sway, allowing attenuation of sway. In the present study, the coupling of postural sway to a moving contact surface was investigated in detail. Head, center of mass, and center of pressure displacement were measured as the contact surface moved rhythmically at 0.1, 0.2, 0.4, 0.6, and 0.8 Hz. Stimulus amplitude decreased with frequency to maintain peak velocity constant across frequency. Head and body sway were highly coherent with contact surface motion at all frequencies except 0.8 Hz, where a drop-off in coherence was observed. Mean frequency of head and body sway matched the driving frequency ≤0.4 Hz. At higher frequencies, non-1:1 coupling was evident. The phase of body sway relative to the touch plate averaged 20–30° at 0.1-Hz drive and decreased approximately linearly to −130° at 0.8-Hz drive. System gain was ∼1 across frequency. The large phase lags observed cannot be accounted for with velocity coupling alone but indicate that body sway also was coupled to the position of the touch plate. Fitting of a linear second-order model to the data suggests that postural control parameters are not fixed but adapt to the moving frame of reference. Moreover, coupling to both position and velocity suggest that a spatial reference frame is defined by the somatosensory system.

scholarly journals Increased static postural sway after energy drink consumption: A randomized trial

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2036
Author(s):  
Martin G. Rosario ◽  
Henry Collazo ◽  
Milagros Mateo ◽  
Maryví Gonzalez-Sola ◽  
Flavia Bayron
Keyword(s):  
Postural Control ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Energy Drinks ◽  
Energy Drink ◽  
The United States ◽  
General Tendency ◽  
Postural Perturbation ◽  
Eyes Closed ◽  
The Central Nervous System

Background: Energy drinks consumption continues to grow since its appearance in the United States in 1997. Available evidence indicates that caffeine, their main ingredient, can alter the central nervous system (CNS). However, it is unknown how energy drinks alter the CNS postural control mechanism. The purpose of this study was to investigate how energy drinks can affect postural control after sensory perturbations during stance. Methods: 20 healthy adults, (11 males; 9 females) averaging 26.1 years of age, stood on a MatScan™ pressure mat, which measured center of pressure (CoP), anteroposterior (AP) and mediolateral (ML) postural sways during eight different balance tests (BALT’s). BALT's were designed to alter or cancel the systems involved in postural control: visual, vestibular and somatosensory. Subjects were randomly assigned to a caffeine group and an energy drink group. MANOVA analysis was performed for all variables of interest. Results: In the caffeine group, the AP sway of the Eyes Closed test on a stable surface was statistically significant. In the energy drinks group, we observed a general tendency of participants to increase CoP slightly, AP and ML sway in most of the BALT’s after the consumption of an energy drink. However, this increase was not statistically significant. These results suggest that in healthy young adults, the sensory re-weighting mechanism can overcome postural perturbation and maintain overall postural control. Conclusions: We observed an overall tendency to increase postural instability after the ingestion of energy drinks.

Effect of a Forefoot Off-loading Postoperative Shoe on Muscle Activity, Posture, and Static Balance

2013 ◽  
Vol 103 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Joanne S. Paton ◽  
Katherine Thomason ◽  
Karl Trimble ◽  
James E. Metcalfe ◽  
Jonathan Marsden
Keyword(s):  
Muscle Activity ◽  
Tibialis Anterior ◽  
Peak Pressure ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Ankle Instability ◽  
Tibialis Anterior Muscle ◽  
Contralateral Side ◽  
Support Surface ◽  
Ankle Muscle

Background: We investigated whether a forefoot off-loading postoperative shoe (FOPS) alters standing posture, ankle muscle activity, and static postural sway and whether any effects are altered by wearing a shoe raise on the contralateral side. Methods: Posture, ankle muscle activity, and postural sway were compared in 14 healthy participants wearing either a FOPS or a control shoe with or without a contralateral shoe raise. Participants were tested under different sensory and support surface conditions. Additionally, reductions in peak pressure under the forefoot while walking were assessed with and without a contralateral shoe raise to determine whether the FOPS continued to achieve its primary off-loading function. Results: Compared with the control condition, wearing a FOPS moved the center of pressure posteriorly, increased tibialis anterior muscle activity, and reduced ankle plantarflexor activity. These changes decreased when a contralateral shoe raise was added. No difference in postural sway was found between footwear conditions. Forefoot peak pressure was always reduced when wearing the FOPS. Conclusions: The posterior shift in center of pressure toward and behind the ankle joint axis is believed to result in the increase in tibialis anterior muscle activity that now acts as the primary stabilizer around the ankle. Instability may, therefore, increase in patients with weak tibialis anterior muscles (eg, diabetic neuropathy) who need to wear offloading devices for ulcer management. We suggest that the addition of a contralateral shoe raise fitted with a FOPS may potentially be beneficial in maintaining stability while off-loading the forefoot in this patient group. (J Am Podiatr Med Assoc 103(1): 36–42, 2013)

scholarly journals Assessment of Visual Reliance in Balance Control: An Inexpensive Extension of the Static Posturography

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jozef Púčik ◽  
Marián Šaling ◽  
Tomáš Lukáč ◽  
Oldřich Ondráček ◽  
Martin Kucharík
Keyword(s):  
Center Of Pressure ◽  
Balance Control ◽  
Low Cost ◽  
Force Plate ◽  
Sensory Information ◽  
Health Concern ◽  
Elderly Subjects ◽  
Upright Stance ◽  
Discrimination Power ◽  
Age Related

Ability of humans to maintain balance in an upright stance and during movement activities is one of the most natural skills affecting everyday life. This ability progressively deteriorates with increasing age, and balance impairment, often aggravated by age-related diseases, can result in falls that adversely impact the quality of life. Falls represent serious problems of health concern associated with aging. Many investigators, involved in different science disciplines such as medicine, engineering, psychology, and sport, have been attracted by a research of the human upright stance. In a clinical practice, stabilometry based on the force plate is the most widely available procedure used to evaluate the balance. In this paper, we have proposed a low-cost extension of the conventional stabilometry by the multimedia technology that allows identifying potentially disturbing effects of visual sensory information. Due to the proposed extension, a stabilometric assessment in terms of line integral of center of pressure (COP) during moving scene stimuli shows higher discrimination power between young healthy and elderly subjects with supposed stronger visual reliance.

scholarly journals A Systematic Review of the Relationship between Physical Activities in Sports or Daily Life and Postural Sway in Upright Stance

2013 ◽  
Vol 43 (11) ◽  
pp. 1171-1189 ◽  
Author(s):  
Henri Kiers ◽  
Jaap van Dieën ◽  
Henk Dekkers ◽  
Harriët Wittink ◽  
Luc Vanhees
Keyword(s):  
Systematic Review ◽  
Postural Sway ◽  
Daily Life ◽  
Physical Activities ◽  
Upright Stance ◽  
The Relationship

scholarly journals Effect of local somatosensory stimulus on postural sway during sit-to-stand movement in the elderly

2021 ◽  
Vol 22 (S1) ◽  
Author(s):  
Peter Annor ◽  
Kiyoung Kwak ◽  
Huigyun Kim ◽  
Dongwook Kim
Keyword(s):  
Young Adults ◽  
Postural Control ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Human Life ◽  
Center Of Mass ◽  
The Elderly ◽  
Individual Response ◽  
Sit To Stand ◽  
Somatosensory Stimulus

Abstract Background Sit-to-stand (STS) is a complex movement that requires successful postural control. Aging is a normal part of human life that leads to weakness of sensory capabilities, resulting in diminished postural control. Therefore, STS movement is a challenging task for the elderly. Local tendon vibration (LTV) can be utilized to assist STS of the elderly by improving postural control. Many studies have revealed that the LTV has various physiological positive effect. However, previous studies did not consider subjects’ individual difference for properties of applied LTV. Also, there are almost no studies to assist and to improve elder’s STS movement. Thus, the purpose of this study was to examine the influence of lower limb LTV on postural sway during STS in the elderly, and to examine whether a specific vibration frequency can increase postural control in the elderly. Results The common characteristic differences between the elderly and younger population during STS movement were analyzed. In addition, the effect of vibration on the center of mass (COM) and the center of pressure (COP) variable responses in young adults and the elderly were investigated. As a result, the elderly exhibit larger COP sway area and higher COP mediolateral (ML) displacement than the young adults. In addition, the elderly generally have lower COM velocities in all directions compared to the young adults. It was found that COP and COM related to postural stability are affected when LTV of the 180 Hz, 190 Hz and 250 Hz is applied to the elderly. Particularly, the 190 Hz vibration induced significant reduction in COP sway area and COP ML displacement. Conclusions These results mean that the LTV contributes to stability of elders’ STS movement by reducing postural sway. Furthermore, a reduction of postural sway depends on frequency of the LTV. These findings suggest that individual response to characteristics of vibration must be considered, and imply that the LTV can be used as rehabilitation therapy to improve postural control in the elderly, and utilized in motion assistive devices to deliver apt vibration frequencies. Trial registration CRIS, KCT0005434, Registered 25 September 2020, Retrospectively registered, https://cris.nih.go.kr/cris/index/index.do

scholarly journals Postural responses of galvanic vestibular stimulation: comparison between groups of older adults and young people

2019 ◽  
Vol 22 (5) ◽  
Author(s):  
Regiane Luz Carvalho ◽  
Matheus Machado Gomes ◽  
Laura Ferreira de Rezende Franco ◽  
Daniela Cristina Carvalho de Abreu
Keyword(s):  
Older Adults ◽  
Muscle Activity ◽  
Muscle Activation ◽  
Center Of Pressure ◽  
Sensory Information ◽  
Vestibular Stimulation ◽  
Galvanic Vestibular Stimulation ◽  
Intensity Level ◽  
Motor Strategy ◽  
Postural Responses

Abstract Objective: To evaluate the effect of vestibular manipulation on the postural sway and muscle activation of younger and older adults. Methods: The study analyzed the effects of three intensity levels of galvanic vestibular stimulation (GVS) (0.3; 0.6 and 1m) on the pattern of muscle activity and center of pressure (CP) displacements of 12 older adults (EG) and 12 young adults (CG) while maintaining their balance on a stable surface, with no vision. Results: The EG showed a positive correlation between CP displacement and muscle activity and GVS intensity. On the other hand, the magnitude of postural response in the EG was not modulated in accordance with GVS intensities. Additionally, during the highest GVS intensity level (1 mA) greater muscle activity was used to increase stiffness, decrease the amplitude of oscillation and ensure stability. This unusual response characterizes a pattern of co-activation and is perhaps a safety mechanism to ensure stability. Conclusion: The EG individuals were not able to select the appropriate motor strategy to efficiently compensate the effects of GVS. This unusual strategy reflects deficits in the vestibular system of older adults, a fact which negatively interferes with their ability to reevaluate sensory information.

scholarly journals Effects of External Perturbations on Anticipatory and Compensatory Postural Adjustments in Patients with Multiple Sclerosis and a Fall History

2018 ◽  
Vol 20 (4) ◽  
pp. 164-172 ◽  
Author(s):  
Shirin Tajali ◽  
Mina Rouhani ◽  
Mohammad Mehravar ◽  
Hossein Negahban ◽  
Elham Sadati ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Fall Prevention ◽  
Muscle Activity ◽  
Center Of Pressure ◽  
Trunk Muscles ◽  
Postural Adjustment ◽  
Postural Adjustments ◽  
External Perturbations ◽  
The Relationship ◽  
Adjustment Mechanisms

Abstract Background: Although previous studies have investigated postural adjustment mechanisms in patients with multiple sclerosis (MS), it seems that no study has yet investigated the relationship between anticipatory and compensatory postural adjustments (APAs and CPAs, respectively) and falls. Methods: Seventeen MS fallers, 17 MS nonfallers, and 15 controls were exposed to a series of expected and unexpected backward pull perturbations applied at the trunk level. The electrical activity of 12 leg and trunk muscles as well as center of pressure displacement were recorded. Results: The MS fallers had delayed muscle activity onsets compared with MS nonfallers and controls. In addition, a significantly lower level of muscle activity during APAs was detected in MS fallers compared with controls. Moreover, in the unexpected condition of perturbation, significantly smaller CPA was observed in MS fallers compared with controls. Both groups of patients with MS required more time to stabilize their center of pressure after both types of perturbations compared with controls. Conclusions: The inability to produce efficient APAs and CPAs during perturbations may explain the high rates of postural instability and falls in patients with MS. Findings from this study provide a background for the development of perturbation-based training programs aimed at balance improvement and fall prevention by restoring mechanisms underlying balance impairments.

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