scholarly journals Losing touch: age-related changes in plantar skin sensitivity, lower limb cutaneous reflex strength, and postural stability in older adults

2016 ◽  
Vol 116 (4) ◽  
pp. 1848-1858 ◽  
Author(s):  
Ryan M. Peters ◽  
Monica D. McKeown ◽  
Mark G. Carpenter ◽  
J. Timothy Inglis

Age-related changes in the density, morphology, and physiology of plantar cutaneous receptors negatively impact the quality and quantity of balance-relevant information arising from the foot soles. Plantar perceptual sensitivity declines with age and may predict postural instability; however, alteration in lower limb cutaneous reflex strength may also explain greater instability in older adults and has yet to be investigated. We replicated the age-related decline in sensitivity by assessing monofilament and vibrotactile (30 and 250 Hz) detection thresholds near the first metatarsal head bilaterally in healthy young and older adults. We additionally applied continuous 30- and 250-Hz vibration to drive mechanically evoked reflex responses in the tibialis anterior muscle, measured via surface electromyography. To investigate potential relationships between plantar sensitivity, cutaneous reflex strength, and postural stability, we performed posturography in subjects during quiet standing without vision. Anteroposterior and mediolateral postural stability decreased with age, and increases in postural sway amplitude and frequency were significantly correlated with increases in plantar detection thresholds. With 30-Hz vibration, cutaneous reflexes were observed in 95% of young adults but in only 53% of older adults, and reflex gain, coherence, and cumulant density at 30 Hz were lower in older adults. Reflexes were not observed with 250-Hz vibration, suggesting this high-frequency cutaneous input is filtered out by motoneurons innervating tibialis anterior. Our findings have important implications for assessing the risk of balance impairment in older adults.

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 141-141
Author(s):  
Joseph Gordon III ◽  
Nicholas Remillard ◽  
Chad Straight ◽  
Rajakumar Nagarajan ◽  
Bruce Damon ◽  
...  

Abstract Decreases in muscle size and function are a general consequence of old age; the precise mechanisms of these changes remain unclear. Recent studies suggest that fat deposition in muscle may also contribute to dysfunction in older adults. Fat content was quantified in the quadriceps, and its effects on function in healthy young (21-45 y) and older (65-75 y) men and women (n=44) of comparable physical activity were compared. A subset of the young matched with the older group for muscle fat content were also examined. Peak fat-free whole muscle cross-sectional area (mCSA; cm2), volume (MV; cm3), fat content (fat fraction, FF; %), specific torque (Nm/mCSA) and peak contraction velocity (Nm∙s-1) were determined using fat-water magnetic resonance imaging and dynamometry (0-300□∙s-1). To examine potential molecular mechanisms of muscle weakness, vastus lateralis biopsies were obtained (n=31) and cross-bridge kinetics of type I and II fibers were determined. FF was higher in older adults than young (8.4±1.2% (SE), 7.6±1.4; p=0.03), while mCSA (48.9±10.4 vs. 64.2±17.3), MV (1536±532 vs. 2112±708), specific torque (2.6±0.4 vs. 3.2±0.4), and peak voluntary contraction velocity (422±20 vs. 441±23) were lower in older than young (p<0.01). Type II fiber myosin attachment rate was slower and attachment time longer in older muscle (p<0.017), providing a potential mechanism for the slowing of peak contraction velocity with age. Notably, differences at the whole muscle and molecular levels remained for the subset of young and older groups matched for FF, suggesting that fat deposition in muscle does not exacerbate age-related changes in function.


BMJ Open ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. e049829
Author(s):  
Elizabeth Tyler ◽  
Fiona Lobban ◽  
Rita Long ◽  
Steven H Jones

ObjectivesAs awareness of bipolar disorder (BD) increases and the world experiences a rapid ageing of the population, the number of people living with BD in later life is expected to rise substantially. There is no current evidence base for the effectiveness of psychological interventions for older adults with BD. This focus group study explored a number of topics to inform the development and delivery of a recovery-focused therapy (RfT) for older adults with BD.DesignA qualitative focus group study.SettingThree focus groups were conducted at a university in the North West of England.ParticipantsEight people took part in the focus groups; six older adults with BD, one carer and one friend.ResultsParticipant’s responses clustered into six themes: (1) health-related and age-related changes in later life, (2) the experience of BD in later life, (3) managing and coping with BD in later life, (4) recovery in later life, (5) seeking helping in the future and (6) adapting RfT for older people.ConclusionsParticipants reported a range of health-related and age-related changes and strategies to manage their BD. Participants held mixed views about using the term ‘recovery’ in later life. Participants were in agreement that certain adaptations were needed for delivering RfT for older adults, based on their experience of living with BD in later life. The data collected as part of the focus groups have led to a number of recommendations for delivering RfT for older adults with BD in a randomised controlled trial (Clinical Trial Registration: ISRCTN13875321).


2016 ◽  
Vol 6 (1-2) ◽  
pp. 119-146 ◽  
Author(s):  
Henrike K. Blumenfeld ◽  
Scott R. Schroeder ◽  
Susan C. Bobb ◽  
Max R. Freeman ◽  
Viorica Marian

Abstract Recent research suggests that bilingual experience reconfigures linguistic and nonlinguistic cognitive processes. We examined the relationship between linguistic competition resolution and nonlinguistic cognitive control in younger and older adults who were either bilingual or monolingual. Participants heard words in English and identified the referent among four pictures while eye-movements were recorded. Target pictures (e.g., cab) appeared with a phonological competitor picture (e.g., cat) and two filler pictures. After each eye-tracking trial, priming probes assessed residual activation and inhibition of target and competitor words. When accounting for processing speed, results revealed that age-related changes in activation and inhibition are smaller in bilinguals than in monolinguals. Moreover, younger and older bilinguals, but not monolinguals, recruited similar inhibition mechanisms during word identification and during a nonlinguistic Stroop task. Results suggest that, during lexical access, bilinguals show more consistent competition resolution and recruitment of cognitive control across the lifespan than monolinguals.


2016 ◽  
Vol 5 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Jennifer J. Heisz ◽  
Ana Kovacevic

Age-related changes in the brain can compromise cognitive function. However, in some cases, the brain is able to functionally reorganize to compensate for some of this loss. The present paper reviews the benefits of exercise on executive functions in older adults and discusses a potential mechanism through which exercise may change the way the brain processes information for better cognitive outcomes. Specifically, older adults who are more physically active demonstrate a shift toward local neural processing that is associated with better executive functions. We discuss the use of neural complexity as a sensitive measure of the neural network plasticity that is enhanced through exercise. We conclude by highlighting the future work needed to improve exercise prescriptions that help older adults maintain their cognitive and physical functions for longer into their lifespan.


Author(s):  
Ernest K. Ofori ◽  
Savitha Subramaniam ◽  
Shuaijie Wang ◽  
Tanvi Bhatt

Background: Recent studies demonstrate improvements in both postural stability and mobility among aging populations and those with stroke who are exposed to dance-based exergaming (DBExG). However, age-related deficits and aging with cortical pathology may lead to distinct movement adaptation patterns during DBExG, which could impact therapeutic outcomes.Aim: The aim of this study was to examine the movement kinematics (postural stability and mobility) of healthy older adults, older adults with stroke, and young adults for different paces of dance during DBExG. Method: The study included 33 particpants (11 participant from each group of healthy older adults, older adults with chronic stroke, and healthy young adults) who performed the DBExG using slow- (SP), medium- (MP), and fast-paced (FP) songs with movements in the anteroposterior (AP) and mediolateral (ML) directions. Center of mass (CoM) sway area, excursion (Ex), and peaks as well as hip, knee, and ankle joint excursions were computed. Results: Results of the study revealed that CoM sway areas and Exs were greater for healthy young adults than for older adults with stroke for the SP dance (p < 0.05) and that there were significantly more AP CoM peaks for young adults than for healthy older adults and those with stroke for the FP dance (p < 0.05). Young adults also exhibited greater hip and ankle Exs than older adults with stroke (p < 0.05) for all song paces. Similarly, knee and ankle Exs were greater for healthy older adults than for older adults with stroke for all song paces (p < 0.05). Conclusion: The quantitative evaluation and comparison of the movement patterns presented for the three groups could provide a foundation for both assessing and designing therapeutic DBExG protocols for these populations.


Author(s):  
Christopher Neville ◽  
Hung Nguyen ◽  
Kim Ross ◽  
Mariana Wingood ◽  
Elizabeth Walker Peterson ◽  
...  

Background Despite sufficient evidence to suggest that lower-limb–related factors may contribute to fall risk in older adults, lower-limb and footwear influences on fall risk have not been systematically summarized for readers and clinicians. The purpose of this study was to systematically review and synethesize the literature related to lower-limb, foot, and footwear factors that may increase the risk of falling among community-dwelling older adults. Methods We searched PubMed, Embase, PsycINFO, CINAHL, Web of Science, Cochrane Library, and AgeLine. To describe the trajectory toward increasing risk of falls, we examined those articles that linked age-related changes in the lower limb or footwear to prospective falls or linked them to evidenced-based fall risk factors, such as gait and balance impairment. Results This systematic review consisted of 81 articles that met the review criteria, and the results reflect a narrative review of the appraised literature for eight pathways of lower-limb–related influences on fall risk in older adults. Six of the eight pathways support a direct link to fall risk. Two other pathways link to the intermediate factors but lack studies that provide evidence of a direct link. Conclusions This review provides strong guidance to advance understanding and assist with managing the link between lower-limb factors and falls in older adults. Due to the lack of literature in specific areas, some recommendations were based on observational studies and should be applied with caution until further research can be completed.


Sign in / Sign up

Export Citation Format

Share Document