scholarly journals Effects of the availability of accurate proprioceptive information on older adults' postural sway and muscle co-contraction

2017 ◽  
Vol 46 (10) ◽  
pp. 2548-2556 ◽  
Author(s):  
Chesney E. Craig ◽  
Glenn H. M. Calvert ◽  
Michail Doumas
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.


2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Hamid Bateni

BACKGROUND: Falls can be detrimental to overall health and quality of life for lower extremity amputees. Most previous studies of postural steadiness focus on quantification of time series variables extracted from postural sway signals. While it has been suggested that frequency domain variables can provide more valuable information, few current studies have evaluated postural sway in amputees using frequency domain variables. OBJECTIVE: To determine time and frequency domain variables of postural sway among lower extremity amputees vs. healthy young and older adult controls. METHODOLOGY: Participants were assigned to 3 groups:  lower extremity amputation (n=6), healthy young adults (n=10), and healthy older adults (n=10). Standing barefoot on a force platform, each individual completed 3 trials of each of 3 standing conditions: eyes open, eyes closed, and standing on a foam balance pad. Time and frequency domain variables of postural sway were computed and analyzed. RESULTS: Comparison of older adults, younger adults, and amputees on the three conditions of standing eyes open, eyes closed, and on foam revealed significant differences between groups. Mean mediolateral (ML) sway distance from the center of pressure (COP), total excursions and sway velocity was significantly higher for amputees and older adults when compared to young adults (p<0.05). Furthermore, power of sway signal was substantially lower for both amputees and older adults. When compared to that of older adults, postural steadiness of amputees was more affected by the eyes closed condition, whereas older adults’ was more affected when sensory and proprioceptive information was perturbed by standing on foam.  CONCLUSION: Our findings showed that fall risk is greater in amputees than in young adults without amputation. Additionally, amputees may rely more heavily on visual information than proprioceptive information for balance, in contrast to older and young adults without amputation.  Layman's Abstract Falls can be detrimental to overall health and quality of life for lower extremity amputees. We evaluated postural sway and concluded that amputees have an increased fall risk and may rely more heavily on visual information for balance than do individuals without amputation. Article PDF Link:https://jps.library.utoronto.ca/index.php/cpoj/article/view/33804/26600 How To Cite: Bateni H. Postural sway in lower extremity amputees and older adults may suggest increased fall risk in amputees. Canadian Prosthetics & Orthotics Journal. 2020;Volume 3, Issue 2, No.4. https://doi.org/10.33137/cpoj.v3i2.33804 Corresponding Author: Hamid Bateni, PhD Physical Therapy Program, School of Allied Health and Communicative Disorders, Northern Illinois University, DeKalb, Illinois, USA.E-mail: [email protected]: https://orcid.org/0000-0001-9083-1817


Author(s):  
Niklas Sörlén ◽  
Andreas Hult ◽  
Peter Nordström ◽  
Anna Nordström ◽  
Jonas Johansson

Abstract Background We aimed to determine the effectiveness of 4 weeks of balance exercise compared with no intervention on objectively measured postural sway. Methods This was a single-center parallel randomized controlled, open label, trial. A six-sided dice was used for allocation at a 1:1-ratio between exercise and control. The trial was performed at a university hospital clinic in Sweden and recruited community-dwelling older adults with documented postural instability. The intervention consisted of progressively challenging balance exercise three times per week, during 4 weeks, with follow-up at week five. Main outcome measures were objective postural sway length during eyes open and eyes closed conditions. Results Sixty-five participants aged 70 years (balance exercise n = 32; no intervention n = 33) were randomized. 14 participants were excluded from analysis because of early dropout before follow-up at week five, leaving 51 (n = 22; n = 29) participants for analysis. No significant differences were detected between the groups in any of the postural sway outcomes. Within-group analyses showed significant improvements in hand grip strength for the intervention group, while Timed Up & Go improvements were comparable between groups but only statistically significant in the control group. Conclusions Performing balance exercise over a four-week intervention period did not acutely improve postural sway in balance-deficient older adults. The lower limit in duration and frequency to achieve positive effects remains unclear. Trial registration Clinical trials NCT03227666, July 24, 2017, retrospectively registered.


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.


2019 ◽  
Vol 121 (2) ◽  
pp. 690-700 ◽  
Author(s):  
Chesney E. Craig ◽  
Michail Doumas

We investigated whether postural aftereffects witnessed during transitions from a moving to a stable support are accompanied by a delayed perception of platform stabilization in older adults, in two experiments. In experiment 1, postural sway and muscle cocontraction were assessed in 11 healthy young, 11 healthy older, and 11 fall-prone older adults during blindfolded stance on a fixed platform, followed by a sway-referenced platform and then by a fixed platform again. The sway-referenced platform was more compliant for young adults, to induce similar levels of postural sway in both age groups. Participants were asked to press a button whenever they perceived that the platform had stopped moving. Both older groups showed significantly larger and longer postural sway aftereffects during platform stabilization compared with young adults, which were pronounced in fall-prone older adults. In both older groups elevated muscle cocontraction aftereffect was also witnessed. Importantly, these aftereffects were accompanied by an illusory perception of prolonged platform movement. After this, experiment 2 examined whether this illusory perception was a robust age effect or an experimental confound due to greater surface compliance in young adults, which could create a larger perceptual discrepancy between moving and stable conditions. Despite exposure to the same surface compliance levels during sway-reference, the perceptual illusion was maintained in experiment 2 in a new group of 14 healthy older adults compared with 11 young adults. In both studies, older adults took five times longer than young adults to perceive platform stabilization. This supports that sensory reweighting is inefficient in older adults. NEW & NOTEWORTHY This is the first paper to show that postural sway aftereffects witnessed in older adults after platform stabilization may be due to a perceptual illusion of platform movement. Surprisingly, in both experiments presented it took older adults five times longer than young adults to perceive platform stabilization. This supports a hypothesis of less efficient sensory reintegration in this age group, which may delay the formation of an accurate postural percept.


Author(s):  
Satoshi Matsuno ◽  
Takuya Yoshiike ◽  
Atsushi Yoshimura ◽  
Sachiyo Morita ◽  
Yusuke Fujii ◽  
...  

Although standing plantar perception training (SPPT) may improve standing postural stability, the underlying neural mechanisms remain unclear. The authors investigated the relationship between regional cortical responses to SPPT using a balance pad and training outcomes in 32 older participants (mean ± SD:72.2 ± 6.0, range:60–87). Regional cortical activity was measured in the bilateral supplementary motor area, primary sensorimotor area, and parietal association area using near-infrared spectroscopy. Postural sway changes were compared before and after SPPT. Changes in two-point plantar discrimination and regional cortical activity during SPPT, associated with standing postural stability improvements, were examined using multiple regression and indicated improved standing postural stability after SPPT (p < .0001). Changes in right parietal association area activity were associated with standing postural stability improvements while barefoot. Overall, the results suggest that right parietal association area activation during SPPT plays a crucial role in regulating standing postural stability and may help develop strategies to prevent older adults from falling.


2019 ◽  
Vol 121 (1) ◽  
pp. 74-84 ◽  
Author(s):  
T. P. Knellwolf ◽  
A. R. Burton ◽  
E. Hammam ◽  
V. G. Macefield

We recently developed an approach for recording from muscle spindles in the intrinsic muscles of the foot in freestanding humans by inserting a tungsten microelectrode into the posterior tibial nerve behind the medial malleolus of the ankle. Here we characterize the behavior of muscle spindles in the small muscles of the foot in 1) seated subjects with the leg horizontal and the foot naturally plantarflexed and 2) standing subjects. In the first study, recordings were made from 26 muscle spindle afferents located within flexor digiti minimi brevis ( n = 4), abductor digiti minimi ( n = 3), quadratus plantae ( n = 3), plantar interossei ( n = 4), flexor digitorum brevis ( n = 3), dorsal interossei ( n = 2), and lumbricals ( n = 2), with one each supplying abductor hallucis, adductor hallucis, and flexor hallucis brevis. The identity of another two muscle afferents was unknown. The majority of the units were silent at rest, only seven (27%) being spontaneously active. Because of the anatomic constraints of the foot, some spindles supplying muscles acting on the toes responded to movements of one or more digits. In the second study, 12 muscle spindle afferents were examined during standing. The ongoing discharge of eight spindle afferents covaried with changes in the center of pressure during postural sway. We conclude that the majority of spindle endings in the small muscles of the foot are silent at rest, which may allow them to encode changes in conformation of the foot when it is loaded during standing. Moreover, these muscle spindle afferents can provide useful proprioceptive information during standing and postural sway. NEW & NOTEWORTHY We have characterized the firing properties of muscle spindles in the intrinsic muscles of the human foot for the first time. The majority of the spindle endings are silent in seated subjects, and most fire tonically during standing, their discharge covarying with center of pressure during postural sway. We conclude that spindle endings in the intrinsic muscles of the foot provide useful proprioceptive information during free standing.


2017 ◽  
Vol 80 (9) ◽  
pp. 539-548
Author(s):  
Anna Rossiter ◽  
Matthew J Allsop ◽  
Rachael K Raw ◽  
Lindsay Howard ◽  
Raymond J Holt ◽  
...  

Introduction Older adults show increased postural sway and a greater risk of falls when completing activities with high cognitive demands. While dual-task approaches have clarified an association between cognitive processes and postural control, it is unclear how manual ability, which is also required for the successful completion of cognitively demanding tasks (such as putting a key into a lock), affects this relationship. Method Kinematic technology was used to explore the relationship between postural sway and manual control in healthy younger and older adults. Participants ( n = 82) remained standing to complete a visual-motor tracking task on a tablet computer. Root mean square tracking error measured manual performance, and a balance board measured deviations in centre of pressure as a marker of postural sway. Results Older adults displayed poorer manual accuracy and increased postural sway across all testing conditions. Conclusions Cognitive capacity can interact with multiple task demands, and in turn affect postural sway in older adults. Improving our understanding of factors that influence postural control will assist falls-prevention efforts and inform clinical practice.


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