The accuracy of perception of a pinch grip force in older adults

2004 ◽  
Vol 82 (8-9) ◽  
pp. 693-701 ◽  
Author(s):  
Sophie J De Serres ◽  
Nathan Z Fang
Keyword(s):  
Older Adults ◽  
Visual Feedback ◽  
Isometric Force ◽  
Hand Function ◽  
The Elderly ◽  
Tactile Feedback ◽  
Elderly Subjects ◽  
Pinch Force ◽  
Pinch Grip ◽  
Effects Of Aging

The fact that humans can execute accurate movements and generate precise muscle forces is very important for hand function. Target-tracking tasks or target-matching tasks are often executed under combined visual and somatosensory feedback. When visual feedback is removed, subjects have to depend on their perception of force. The objective of the present study was to estimate the effects of aging on the perception of a pinch force produced by the thumb and index finger. In a first set of trials, young (n = 12, age = 25.3 ± 2.4 years) and elderly (n = 12, age = 71.5 ± 3.3 years) healthy individuals were asked to reproduce pinch forces which were equivalent to 5%, 20%, and 40% of their maximal pinch force (MPF). Prior to the execution of these trials, the subjects were familiarized with the force levels by matching targets displayed on a screen. They were then asked to reproduce each of these forces without any visual or verbal feedback. The results showed a larger error in the reproduced force for the elderly subjects when compared with the young adults. However, this larger error was mainly due to an initial overshoot in the force to be reproduced, followed by a gradual decrease towards the appropriate force. This transient overshoot was rarely seen in the performance of the younger subjects. In a second set of trials, the same subjects were asked to produce a pinch force of 5%, 20%, and 40% of MPF with 1 hand using visual feedback. They were also instructed to simultaneously apply a comparable pinch force with the other hand (without any feedback). For both young and older adults, the pinch forces produced by the 2 hands were the same. In addition, in both blocks of trials, hand dominance had no effects on the performance for all subjects. These results suggest that normal aging affects the production of force based on sensorimotor memory rather more than it affects comparative outputs from central descending commands.Key words: prehension, isometric force, aging, tactile feedback.

scholarly journals Arterial-cardiac baroreflex function: insights from repeated squat-stand maneuvers

2009 ◽  
Vol 297 (1) ◽  
pp. R116-R123 ◽  
Author(s):  
Rong Zhang ◽  
Jurgen A. H. R. Claassen ◽  
Shigeki Shibata ◽  
Sinem Kilic ◽  
Kristin Martin-Cook ◽  
...  
Keyword(s):  
Transfer Function ◽  
Arterial Pressure ◽  
Body Position ◽  
The Elderly ◽  
Elderly Subjects ◽  
Pulley System ◽  
New Approach ◽  
Baroreflex Function ◽  
Effects Of Aging ◽  
Transfer Function Gain

To assess baroreflex function under closed-loop conditions, a new approach was used to generate large and physiological perturbations in arterial pressure. Blood pressure (BP) and R-R interval were recorded continuously in 20 healthy young (33 ± 8 yr) and eight elderly subjects (66 ± 6 yr). Repeated squat-stand maneuvers at the frequencies of 0.05 and 0.1 Hz were performed to produce periodic oscillations in BP to provoke the baroreflex. To assess the effects of the muscle reflex and/or central command on the baroreflex, passive squat-stand maneuvers were conducted using a pulley system to assist changes in body position. Transfer function between changes in BP and R-R interval was estimated to assess the arterial-cardiac baroreflex. Relative to resting conditions, large and coherent oscillations in BP and R-R interval were produced during both active and passive squat-stand maneuvers. However, changes in BP were smaller during passive than during active maneuvers. Changes in R-R interval were reduced commensurately. Therefore, transfer function gain did not change between the two maneuvers. Compared with the young, transfer function gain was reduced and the phase became more negative in the elderly, demonstrating the well-known effects of aging on reducing baroreflex sensitivity. Collectively, these findings suggest that the changes in R-R interval elicited by BP perturbations during squat-stand maneuvers are mediated primarily by a baroreflex mechanism. Furthermore, baroreflex function can be assessed using the transfer function method during large perturbations in arterial pressure.

scholarly journals Effects of aging on motor control strategies during bimanual isometric force control

2019 ◽  
Vol 27 (4) ◽  
pp. 267-275
Author(s):  
Yan Jin ◽  
JiWon Seong ◽  
YoungChae Cho ◽  
BumChul Yoon
Keyword(s):  
Older Adults ◽  
Motor Control ◽  
Control Strategy ◽  
Force Control ◽  
Isometric Force ◽  
Control Strategies ◽  
Force Variability ◽  
Dual Tasking ◽  
Effects Of Aging ◽  
Force Accuracy

Aging-induced degeneration of the neuromuscular system would result in deteriorated complex muscle force coordination and difficulty in executing daily activities that require both hands. The aim of this study was to provide a basic description of how aging and dual-task activity would affect the motor control strategy during bimanual isometric force control in healthy adults. In total, 17 young adults (aged 25.1 ± 2.4 years) and 14 older adults (aged 72.6 ± 3.4 years) participated in the study. The subjects were instructed to press both hands simultaneously to match the 1 Hz sine curve force under two conditions (with or without calculation) with continuous visual feedback. Differences in bimanual motor synergy, bimanual coordination, force accuracy, force variability, and calculation speed were compared. This study found that the specific motor control strategy of older adults involved a decreased bimanual force control ability with both increased VUCM and VORT, and was not influenced by dual tasking. These findings might have implications for establishing interventions for aging-induced hand force control deficits.

Neuroendocrine rhythms and sleep in aging men

1991 ◽  
Vol 260 (4) ◽  
pp. E651-E661 ◽  
Author(s):  
A. van Coevorden ◽  
J. Mockel ◽  
E. Laurent ◽  
M. Kerkhofs ◽  
M. L'Hermite-Baleriaux ◽  
...  
Keyword(s):  
Young Male ◽  
Extended Period ◽  
The Elderly ◽  
Thyroid Stimulating Hormone ◽  
Temporal Organization ◽  
Elderly Subjects ◽  
Elderly Men ◽  
Age Related ◽  
Aging Men ◽  
Effects Of Aging

To delineate the physiological effects of aging on basal levels and temporal patterns of neuroendocrine secretions, the 24-h profiles of cortisol, thyroid-stimulating hormone (TSH), melatonin, prolactin, and growth hormone (GH) levels were simultaneously obtained at frequent intervals in eight healthy, active elderly men, age 67-84 yr and in eight young male adults, age 20-27 yr. The study was preceded by an extended period of habituation to laboratory conditions, and sleep was polygraphically recorded. Mean cortisol levels in the elderly were normal, but the amplitude of the circadian rhythm was reduced. Circulating levels of daytime and nighttime levels of both TSH and GH were greatly diminished in old age. In contrast, prolactin and melatonin concentrations were decreased during the nighttime only. The circadian rises of cortisol, TSH, and melatonin occurred 1-1.5 h earlier in elderly subjects, and the distribution of rapid-eye-movement stages during sleep was similarly advanced, suggesting that circadian timekeeping is modified during normal senescence. Despite perturbations of sleep, sleep-related release of GH and prolactin occurred in all elderly men. Age-related decreases in hormonal levels were associated with a decrease in the amplitude, but not the frequency, of secretory pulses. These findings demonstrate that the normal process of aging involves alterations in the central mechanisms controlling the temporal organization of endocrine release in addition to a reduction of secretory outputs.

scholarly journals Age-related changes in multifinger synergies in accurate moment of force production tasks

2007 ◽  
Vol 102 (4) ◽  
pp. 1490-1501 ◽  
Author(s):  
Halla Olafsdottir ◽  
Wei Zhang ◽  
Vladimir M. Zatsiorsky ◽  
Mark L. Latash
Keyword(s):  
Hand Function ◽  
The Elderly ◽  
Time Profile ◽  
Uncontrolled Manifold ◽  
Elderly Subjects ◽  
Total Force ◽  
Dominant Hand ◽  
Total Moment ◽  
Age Related ◽  
Young Subjects

The purpose of this investigation was to document and quantify age-related differences in the coordination of fingers during a task that required production of an accurate time profile of the total moment of force by the four fingers of a hand. We hypothesized that elderly subjects would show a decreased ability to stabilize a time profile of the total moment of force, leading to larger indexes of moment variability compared with young subjects. The subjects followed a trapezoidal template on a computer screen by producing a time profile of the total moment of force while pressing down on force sensors with the four fingers of the right (dominant) hand. To quantify synergies, we used the framework of the uncontrolled manifold hypothesis. The elderly subjects produced larger total force, larger variance of both total force and total moment of force, and larger involvement of fingers that produced moment of force against the required moment direction (antagonist moment). This was particularly prominent during supination efforts. Young subjects showed covariation of commands to fingers across trials that stabilized the moment of total force (moment-stabilizing synergy), while elderly subjects failed to do so. Both subject groups showed similar indexes of covariation of commands to the fingers that stabilized the time profile of the total force. The lack of moment-stabilizing synergies may be causally related to the documented impairment of hand function with age.

scholarly journals Determining Whether Tai Chi Chuan is Related to the Updating Function in Older Adults: Differences Between Experts and Novices

2021 ◽  
Author(s):  
Yuan Yang ◽  
Tingting Chen ◽  
Xiaoxia Yuan ◽  
Xiaoke Zhong ◽  
Shoufu Yan ◽  
...  
Keyword(s):  
Older Adults ◽  
Tai Chi ◽  
The Elderly ◽  
Elderly Subjects ◽  
Cross Sectional ◽  
Tai Chi Chuan ◽  
Novice Group ◽  
Healthy Elderly ◽  
Back Task

Abstract Background: Tai Chi Chuan (TCC) is one effective method used to delay cognitive decline in older adults. However, the relationship between the long-term practice of TCC and the crucial working memory updating function of the brain in the elderly has not been comprehensively researched.Objective: This cross-sectional study explores how behavioral performance in a laboratory setting is related to long term practice of TCC on the updating function in older people using reaction times (RTs) of N-back tasks. Methods: 26 healthy elderly people participated in this experiment. According to the length of time TCC was practiced, 13 subjects in the TCC group had more than 5 years’ experience of TCC exercise, and 13 elderly subjects who had not been systematically exposed to mind-body exercise were assigned to the novice group. The N-back task was administered to every participant to evaluate the updating function. Results: The TCC group had faster RTs compared to the novice group (p<0.05); For the 1-back task, the TCC group showed faster RTs than the novice group. For the 2-back task, the novice group exhibited faster RTs than the TCC group. Conclusions: TCC experts exhibit greater updating function as compared to TCC novices. Long-term TCC appears to be positive associated with the updating function of older adults, making it an effective exercise to maintain cognitive function in the elderly.

Older adults can maximally activate the biceps brachii muscle by voluntary command

1998 ◽  
Vol 84 (1) ◽  
pp. 284-291 ◽  
Author(s):  
Sophie J. De Serres ◽  
Roger M. Enoka
Keyword(s):  
Older Adults ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Maximum Voluntary Contraction ◽  
The Elderly ◽  
Voluntary Contraction ◽  
Elderly Subjects ◽  
Biceps Brachii Muscle ◽  
Activation Level ◽  
Voluntary Command

De Serres, Sophie J., and Roger M. Enoka. Older adults can maximally activate the biceps brachii muscle by voluntary command. J. Appl. Physiol. 84(1): 284–291, 1998.—Because some of the decline in strength with age may be explained by an impairment of muscle activation, the purpose of this study was to determine the activation level achieved in biceps brachii by older adults during a maximum voluntary contraction (MVC). This capability was assessed with two superimposition techniques: one calculated the activation level that was achieved during an MVC, and the other provided an estimate of the expected MVC force based on extrapolation with submaximal forces. The activation level in biceps brachii was incomplete (<100%) for the young ( n = 16) and elderly ( n = 16) subjects, with the elderly subjects exhibiting the greater deficit. In contrast, there was no difference between the measured and expected MVC forces for either group of subjects, whether the extrapolation involved a third-order polynomial or linearization of the data. Because of the lower signal-to-noise ratio associated with the measurement of activation level and the greater number of measurements that contributed to the estimate of the expected MVC force, we conclude that the older adults were able to achieve complete activation of the biceps brachii muscle during an MVC.

Age-related Changes in Object Processing and Contextual Binding Revealed Using fMR Adaptation

2006 ◽  
Vol 18 (4) ◽  
pp. 495-507 ◽  
Author(s):  
Michael W. L. Chee ◽  
Joshua O. S. Goh ◽  
Vinod Venkatraman ◽  
Jiat Chow Tan ◽  
Angela Gutchess ◽  
...  
Keyword(s):  
The Elderly ◽  
Elderly Subjects ◽  
Object Processing ◽  
Lateral Occipital Complex ◽  
Simultaneous Processing ◽  
Age Related ◽  
Contextual Integration ◽  
Effects Of Aging ◽  
Contextual Binding ◽  
Naturalistic Pictures

Using fMR adaptation, we studied the effects of aging on the neural processing of passively viewed naturalistic pictures composed of a prominent object against a background scene. Spatially distinct neural regions showing specific patterns of adaptation to objects, background scenes, and contextual integration (binding) were identified in young adults. Older adults did not show adaptation responses corresponding to binding in the medial-temporal areas. They also showed an adaptation deficit for objects whereby their lateral occipital complex (LOC) did not adapt to repeated objects in the context of a changing background. The LOC could be activated, however, when objects were presented without a background. Moreover, the adaptation deficit for objects viewed against backgrounds was reversed when elderly subjects were asked to attend to objects while viewing these complex pictures. These findings suggest that the elderly have difficulty with simultaneous processing of objects and backgrounds that, in turn, could contribute to deficient contextual binding.

Effect of aging on ventilatory response to exercise and CO2

1984 ◽  
Vol 56 (5) ◽  
pp. 1143-1150 ◽  
Author(s):  
M. J. Brischetto ◽  
R. P. Millman ◽  
D. D. Peterson ◽  
D. A. Silage ◽  
A. I. Pack
Keyword(s):  
Ventilatory Response ◽  
Minute Ventilation ◽  
Work Load ◽  
The Elderly ◽  
Co2 Production ◽  
Elderly Subjects ◽  
Control Group ◽  
Effects Of Aging ◽  
Response To Exercise ◽  
The Relationship

Studies were performed to determine the effects of aging on the ventilatory responsiveness to two known respiratory stimulants, inhaled CO2 and exercise. Although explanation of the physiological mechanisms underlying development of exercise hyperpnea remains elusive, there is much circumstantial evidence that during exercise, however mediated, ventilation is coupled to CO2 production. Thus matched groups of young and elderly subjects were studied to determine the relationship between increasing ventilation and increasing CO2 production (VCO2) during steady-state exercise and the change in their minute ventilation in response to progressive hypercapnia during CO2 rebreathing. We found that the slope of the ventilatory response to hypercapnia was depressed in elderly subjects when compared with the younger control group (delta VE/delta PCO2 = 1.64 +/- 0.21 vs. 2.44 +/- 0.40 l X min-1 X mmHg-1, means +/- SE, respectively). In contrast, the slope of the relationship between ventilation and CO2 production during exercise in the elderly was greater than that of younger subjects (delta VE/delta VCO2 = 29.7 +/- 1.19 vs. 25.3 +/- 1.54, means +/- SE, respectively), as was minute ventilation at a single work load (50 W) (32.4 +/- 2.3 vs. 25.7 +/- 1.54 l/min, means +/- SE, respectively). This increased ventilation during exercise in the elderly was not produced by arterial O2 desaturation, and increased anaerobiasis did not play a role. Instead, the increased ventilation during exercise seems to compensate for increased inefficiency of gas exchange such that exercise remains essentially isocapnic. In conclusion, in the elderly the ventilatory response to hypercapnia is less than in young subjects, whereas the ventilatory response to exercise is greater.

Effects of aging on human plasma renin: simultaneous multiple assays of enzyme activity and immunoactivity of plasma renin

1989 ◽  
Vol 120 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Jitsuo Higaki ◽  
Ryuichi Morishita ◽  
Toshio Ogihara ◽  
Masaru Nishiura
Keyword(s):  
Plasma Renin Activity ◽  
Plasma Renin ◽  
Normal Subjects ◽  
The Elderly ◽  
Renin Activity ◽  
Elderly Subjects ◽  
Plasma Renin Concentration ◽  
Active Renin ◽  
Effects Of Aging ◽  
Renin Content

Abstract. The effects of aging on plasma renin in normotensive volunteers were evaluated by conventional indirect RIA of angiotensin I and a newly developed direct RIA. Plasma renin activity and the plasma concentration of active renin measured by radiometric assay with monoclonal antibody were significantly lower in 14 subjects over 60 years than in 15 subjects under 60 years (plasma renin activity: 0.5 ± 0.1 vs 1.7 ± 0.4 nmol · 1−1 · h−1, P< 0.01; plasma active renin: 0.50 ± 0.05 vs 0.87 ± 0.13 pmol/l, P< 0.01, means ± sem), wheres neither the total renin activity nor the total plasma renin concentration measured by the newly developed immunometric assay were different in the two groups. In another study, the plasma renin concentration, total renin concentration and immunoreactive total renin concentration measured by direct RIA with polyclonal antibody were determined in 17 young (<60 years) and 12 elderly (≧60 years) subjects. Plasma renin concentration was significantly lower in the elderly subjects (1.7 ± 0.2 nmol · 1−1 · h−1) than in young subjects (3.4 ± 0.7 nmol · 1−1 · h−1, P< 0.05), but the total renin concentration and immunoreactive total renin concentrations in the two groups were not significantly different. These results indicate that the total renin content of the plasma does not change, whereas the active renin content decreases with age in normal subjects, and suggest that activation of prorenin to active renin may be impaired in elderly subjects.

Temporal Characteristics of the Speech of Normal Elderly Adults

1987 ◽  
Vol 30 (4) ◽  
pp. 522-529 ◽  
Author(s):  
Bruce L. Smith ◽  
Jan Wasowicz ◽  
Judy Preston
Keyword(s):  
Young Adults ◽  
Aging Process ◽  
The Elderly ◽  
Normal Aging ◽  
Elderly Subjects ◽  
Elderly Adults ◽  
Temporal Characteristics ◽  
Acoustic Analyses ◽  
Effects Of Aging ◽  
Fast Rates

A number of physical and psychological changes occur as a result of the normal aging process. These changes often result in an increase in the time subjects require to perform various motor (and sensory) tasks. Although the effects of aging upon a variety of behaviors have been quite well documented, considerably less information is available concerning how normal aging may affect speech production. The present study examined temporal characteristics of the speech of 10 normal, elderly adults and 10 young adults who produced a variety of words and sentences at both normal and fast speaking rates. Acoustic analyses indicated that the elderly adults' segment, syllable, and sentence durations were 20 to 25% longer than those of the young adults at both the normal and the fast rates of speech. In addition to comparisons that were made between these two groups of subjects, comparisons were also made with durations of the speech of young children studied in previous research. It was observed that the elderly subjects tended to produce durations comparable to those of 6- and 7-year-old children.

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