Adaptation and Reintegration of Proprioceptive Information in Young and Older Adults' Postural Control

2010 ◽  
Vol 104 (4) ◽  
pp. 1969-1977 ◽  
Author(s):  
Michail Doumas ◽  
Ralf Th. Krampe

We investigated age-related changes in adaptation and sensory reintegration in postural control without vision. In two sessions, participants adapted their posture to sway reference and to reverse sway reference conditions, the former reducing (near eliminating) and the latter enhancing (near doubling) proprioceptive information for posture by means of support-surface rotations in proportion to body sway. Participants stood on a stable platform for 3 min (baseline) followed by 18 min of sway reference or reverse sway reference (adaptation) and finally again on a stable platform for 3 min (reintegration). Results showed that when inaccurate proprioception was introduced, anterior-posterior (AP) sway path length increased in comparable levels in the two age groups. During adaptation, young and older adults reduced postural sway at the same rate. On restoration of the stable platform in the reintegration phase, a sizeable aftereffect of increased AP path length was observed in both groups, which was greater in magnitude and duration for older adults. In line with linear feedback models of postural control, spectral analyses showed that this aftereffect differed between the two platform conditions. In the sway-referenced condition, a switch from low- to high-frequency COP sway marked the transition from reduced to normal proprioceptive information. The opposite switch was observed in the reverse sway referenced condition. Our findings illustrate age-related slowing in participants' postural control adjustments to sudden changes in environmental conditions. Over and above differences in postural control, our results implicate sensory reweighting as a specific mechanism highly sensitive to age-related decline.

1999 ◽  
Vol 9 (2) ◽  
pp. 103-109
Author(s):  
Reginald L. Reginella ◽  
Mark S. Redfern ◽  
Joseph M. Furman

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.


2019 ◽  
Author(s):  
Michail Doumas ◽  
Rebekah Knox ◽  
Cara O’Brien ◽  
Chesney E. Craig

AbstractWe investigated the presence of proprioceptive deficits in adults with Autism Spectrum Disorder (ASD), by assessing peripheral proprioceptive information (or proprioceptive acuity) as well as integration of proprioceptive information in the context of postural control. We hypothesized that proprioceptive acuity would be intact but that integration during a postural control task would be impaired. Sixteen adults with ASD and sixteen Neurotypical (NT) adults were screened using an IQ test and the adolescent-adult sensory profile. Proprioceptive acuity was assessed using an ankle Joint Position Sense (JPS) task and integration of proprioceptive information was assessed using a postural adaptation task. This task comprised standing upright, without vision in three phases: standing on a fixed surface for 2 minutes (baseline), followed by standing on a surface tilting in proportion to participants’ body sway, or support-surface sway reference for 3 minutes (adaptation) and finally standing on the restored fixed surface for 3 minutes (reintegration). Results showed no group differences in proprioceptive acuity and in the baseline phase, but greater postural sway during adaptation in individuals with ASD compared with NT controls. Specifically, group differences were not present in the first 30s of adaptation, but emerged after the second window suggesting a deficit in sensory integration of proprioception in adults with ASD. Our results suggest that peripheral proprioceptive information is intact in ASD but neural sensory integration of proprioception is impaired in this group.


2004 ◽  
Vol 91 (1) ◽  
pp. 410-423 ◽  
Author(s):  
Robert J. Peterka ◽  
Patrick J. Loughlin

Upright stance in humans is inherently unstable, requiring corrective action based on spatial-orientation information from sensory systems. One might logically predict that environments providing access to accurate orientation information from multiple sensory systems would facilitate postural stability. However, we show that, after a period in which access to accurate sensory information was reduced, the restoration of accurate information disrupted postural stability. In eyes-closed trials, proprioceptive information was altered by rotating the support surface in proportion to body sway (support surface “sway-referencing”). When the support surface returned to a level orientation, most subjects developed a transient 1-Hz body sway oscillation that differed significantly from the low-amplitude body sway typically observed during quiet stance. Additional experiments showed further enhancement of the 1-Hz oscillation when the surface transitioned from a sway-referenced to a reverse sway-referenced motion. Oscillatory behavior declined with repetition of trials, suggesting a learning effect. A simple negative feedback-control model of the postural control system predicted the occurrence of this 1-Hz oscillation in conditions where too much corrective torque is generated in proportion to body sway. Model simulations were used to distinguish between two alternative explanations for the excessive corrective torque generation. Simulation results favor an explanation based on the dynamic reweighting of sensory contributions to postural control rather than a load-compensation mechanism that scales torque in proportion to a fixed combination of sensory-orientation information.


Author(s):  
Koenraad Vandevoorde ◽  
Jean-Jacques Orban de Xivry

The ability to adjust movements to changes in the environment declines with aging. This age-related decline is caused by the decline of explicit adjustments. However, implicit adaptation remains intact and might even be increased with aging. Since proprioceptive information has been linked to implicit adaptation, it might well be that an age-related decline in proprioceptive acuity might be linked to the performance of older adults in implicit adaptation tasks. Indeed, age-related proprioceptive deficits could lead to altered sensory integration with an increased weighting of the visual sensory-prediction error. Another possibility is that reduced proprioceptive acuity results in an increased reliance on predicted sensory consequences of the movement. Both these explanations led to our preregistered hypothesis: we expected a relation between the decline of proprioception and the amount of implicit adaptation across ages. However, we failed to support this hypothesis. Our results question the existence of reliability-based integration of visual and proprioceptive signals during motor adaptation.


1999 ◽  
Vol 9 (6) ◽  
pp. 435-444
Author(s):  
Rosemary A. Speers ◽  
Neil T. Shepard ◽  
Arthur D. Kuo

The Sensory Organization Test protocol of the EquiTest system (NeuroCom International, Clackamas Oregon) tests utilization of visual, vestibular, and proprioceptive sensors by manipulating the accuracy of visual and/or somatosensory inputs during quiet stance. In the standard Sensory Organization Test, both manipulation of sensory input (sway-referencing) and assessment of postural sway are based on ground reaction forces measured from a forceplate. The purpose of our investigation was to examine the use of kinematic measurements to provide a more direct feedback signal for sway-referencing and for assessment of sway. We compared three methods of sway-referencing: the standard EquiTest method based on ground reaction torque, kinematic feedback based on servo-controlling to shank motion, and a more complex kinematic feedback based on servo-controlling to follow position of the center of mass (COM) as calculated from a two-link biomechanical model. Fifty-one normal subjects (ages 20–79) performed the randomized protocol. When using either shank or COM angle for sway-referencing feedback as compared to the standard EquiTest protocol, the Equilibrium Quotient and Strategy Score assessments were decreased for all age groups in the platform sway-referenced conditions (SOT 4, 5, 6). For all groups of subjects, there were significant differences in one or more of the kinematic sway measures of shank, hip, or COM angle when using either of the alternative sway-referencing parameters as compared to the standard EquiTest protocol. The increased sensitivities arising from use of kinematics had the effect of amplifying differences with age. For sway-referencing, the direct kinematic feedback may enhance ability to reduce proprioceptive information by servo-controlling more closely to actual ankle motion. For assessment, kinematics measurements can potentially increase sensitivity for detection of balance disorders, because it may be possible to discriminate between body sway and acceleration and to determine the phase relationship between ankle and hip motion.


2014 ◽  
Vol 30 (4) ◽  
pp. 542-546 ◽  
Author(s):  
Dennis E. Anderson ◽  
Christopher T. Franck ◽  
Michael L. Madigan

The effects of gait speed and step length on the required coefficient of friction (COF) confound the investigation of age-related differences in required COF. The goals of this study were to investigate whether age differences in required COF during self-selected gait persist when experimentally-controlling speed and step length, and to determine the independent effects of speed and step length on required COF. Ten young and 10 older healthy adults performed gait trials under five gait conditions: self-selected, slow and fast speeds without controlling step length, and slow and fast speeds while controlling step length. During self-selected gait, older adults walked with shorter step lengths and exhibited a lower required COF. Older adults also exhibited a lower required COF when walking at a controlled speed without controlling step length. When both age groups walked with the same speed and step length, no age difference in required COF was found. Thus, speed and step length can have a large influence on studies investigating age-related differences in required COF. It was also found that speed and step length have independent and opposite effects on required COF, with step length having a strong positive effect on required COF, and speed having a weaker negative effect.


Author(s):  
Lauren Werner ◽  
Gaojian Huang ◽  
Brandon J. Pitts

The number of older adults is growing significantly worldwide. At the same time, technological developments are rapidly evolving, and older populations are expected to interact more frequently with such sophisticated systems. Automated speech recognition (ASR) systems is an example of one technology that is increasingly present in daily life. However, age-related physical changes may alter speech production and limit the effectiveness of ASR systems for older individuals. The goal of this paper was to summarize the current knowledge on ASR systems and older adults. The PRISMA method was employed and 17 studies were compared on the basis of word error rate (WER). Overall, WER was found to be influenced by age, gender, and the number of speech samples used to train ASR systems. This work has implications for the development of future human-machine technologies that will be used by a wide range of age groups.


Author(s):  
Hyun Gu Kang ◽  
Jonathan B. Dingwell

Older adults commonly walk slower, which many believe helps improve their walking stability. However, they remain at increased risk of falls. We investigated how differences in age and walking speed independently affect dynamic stability during walking, and how age-related changes in leg strength and ROM affected this relationship. Eighteen active healthy older and 17 younger adults walked on a treadmill for 5 minutes each at each of 5 speeds (80–120% of preferred). Local divergence exponents and maximum Floquet multipliers (FM) were calculated to quantify each subject’s responses to small inherent perturbations during walking. These older adults exhibited the same preferred walking speeds as the younger subjects (p = 0.860). However, these older adults still exhibited greater local divergence exponents (p<0.0001) and higher maximum FM (p<0.007) than young adults at all walking speeds. These older adults remained more unstable (p<0.04) even after adjusting for declines in both strength and ROM. In both age groups, local divergence exponents decreased at slower speeds and increased at faster speeds (p<0.0001). Maximum FM showed similar changes with speed (p<0.02). The older adults in this study were healthy enough to walk at normal speeds. However, these adults were still more unstable than the young adults, independent of walking speed. This greater instability was not explained by loss of leg strength and ROM. Slower speeds led to decreased instability in both groups.


2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S841-S842
Author(s):  
Madeline J Nichols ◽  
Jennifer A Bellingtier ◽  
Frances Buttelmann

Abstract Every day we use emotion words to describe our experiences, but past research finds that the meanings of these words can vary. Furthermore, historical shifts in language use and experiential knowledge of the emotions may contribute to age-differences in what these emotion words convey. We examined age-related differences in the valence, arousal, and expression connoted by the words anger, love, and sadness. We predicted age-related differences in the semantic meanings of the words would emerge such that older adults would more clearly differentiate the positivity/negativity of the words, whereas younger adults would report higher endorsement for the conveyed arousal and expression. Participants included American and German older adults (N=61; mean age=68.98) and younger adults (N=77; mean age=20.77). Using the GRID instrument (Swiss Center for Affective Sciences, 2013), they rated each emotion word for its valence, arousal, and expression when used by a speaker of the participant’s native language. Across emotions and dimensions, older adults were generally more moderate in their understanding of emotion words. For example, German older adults rated anger and sadness as suggesting the speaker felt less bad and more good than the younger adults. American older adults rated love as connoting the speaker felt more bad and less good than younger adults. Arousal ratings were higher for German younger, as opposed to older, adults. Cultural differences were most pronounced for sadness such that German participants gave more moderate answers than American participants. Overall, our research suggests that there are age-related differences in the understanding of emotion words.


BMJ Open ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. e027728 ◽  
Author(s):  
Siobhan Leahy ◽  
Marica Cassarino ◽  
Matthew DL O' Connell ◽  
Liam Glynn ◽  
Rose Galvin

IntroductionTwo major global health challenges are the rapidly ageing population and the high prevalence of obesity in all age groups. Older adults are also susceptible to age-related loss of muscle strength, termed dynapaenia. The co-occurrence of both obesity and dynapaenia, termed dynapaenic obesity (DO), has been associated with poorer health outcomes and increased healthcare usage compared with either state alone. The purpose of this systematic review is to quantify the prevalence and incidence of DO in older adult populations, and to explore the association between DO and health outcomes, specifically chronic disease and multimorbidity, functional disability and healthcare usage.Methods and analysisUsing the Meta-analyses Of Observational Studies in Epidemiology guidelines, we will conduct a systematic review of cross-sectional and longitudinal observational studies of older adults, which include measures of DO and specified outcomes. Detailed literature searches of will be conducted using six electronic databases: Excerpta Medica dataBASE (EMBASE), PubMed, MEDLINE, SCOPUS, ScienceDirect and Cumulative Index of Nursing and Allied Health Complete (CINAHL), including articles published from database inception until Febuary 2019. The reference lists of included articles will also be searched. Two independent reviewers will undertake a three-step screening and review process using the Population, Risk Factor, Outcome framework to define eligibility. The Newcastle Ottawa Scale for non-randomised studies will be used to assess risk of bias and to rate study quality. The findings will be synthesised in a narrative summary, and a meta-analysis will be conducted where appropriate.Ethics and disseminationEthical approval is not required for this systematic review. Findings from this research will be submitted for peer-reviewed publication in academic journals, and presented at relevant academic conferences.PROSPERO registration numberCRD42018112471.


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