首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Physical activity has been shown to benefit brain and cognition in late adulthood. However, this effect is still unexplored in terms of brain signal complexity, which reflects the level of neural adaptability and efficiency during cognitive processing that cannot be acquired via averaged neuroelectric signals. Here we employed multiscale entropy analysis (MSE) of electroencephalography (EEG), a new approach that conveys important information related to the temporal dynamics of brain signal complexity across multiple time scales, to reveal the association of physical activity with neural adaptability and efficiency in elderly adults. A between-subjects design that included 24 participants (aged 66.63 ± 1.31 years; female = 12) with high physical activity and 24 age- and gender-matched low physical activity participants (aged 67.29 ± 1.20 years) was conducted to examine differences related to physical activity in performance and MSE of EEG signals during a visuo-spatial cognition task. We observed that physically active elderly adults had better accuracy on both visuo-spatial attention and working memory conditions relative to their sedentary counterparts. Additionally, these physically active elderly adults displayed greater MSE values at larger time scales at the Fz electrode in both attention and memory conditions. The results suggest that physical activity may be beneficial for adaptability of brain systems in tasks involving visuo-spatial information. MSE thus might be a promising approach to test the effects of the benefits of exercise on cognition.  相似文献   

2.
Children with Developmental Coordination Disorder (DCD) are physically less active, preferring more sedentary behavior and are at risk of developing health problems or becoming overweight. 18 children (age 6–10 years) with lower levels of motor coordination attending a primary school in a low-income community in South Africa (score on Movement Assessment Battery for Children Second edition equal to or below the 5th percentile) were selected to participate in the study and were age-matched with typically developing peers (TD). Both groups of children engaged in 20 min of active Nintendo Wii Fit gaming on the balance board, twice a week for a period of five weeks. All children were tested before and after the intervention using the lower limb items of the Functional Strength Measurement, the 5 × 10 meter sprint test, the 5 × 10 meter slalom sprint test, and the Balance, Running speed and Agility subtest of the Bruininks Oseretsky Test of Motor Proficiency 2nd edition (BOT-2).After intervention, both groups of children improved in functional strength and anaerobic fitness. The magnitude of these changes was not related to participant’s motor coordination level. However, differences in change between the TD and DCD group were apparent on the motor performance tests; children with DCD seemed to benefit more in balance skills of the BOT-2, while the TD children improved more in the Running speed and Agility component of the BOT-2. Compliance to the study protocol over 5 weeks was high and the effect on physical functioning was shown on standardized measures of physical performance validated for children with and without DCD.  相似文献   

3.
Psychological processes may influence balance and contribute to the risk of falls in older people. While a self-reported fear of falling is associated with increased postural sway, inducing fear using an elevated platform can lead to reduced sway, suggesting different underlying mechanisms whereby fear may influence balance control. This study examined changes in postural sway, muscle activity and physiological measures of arousal while standing on a 65 cm elevated platform, compared to floor level, in young and older adults. The older adults were classified as fall concerned or not fall concerned based on the Falls Efficacy Scale-International and anxious or not anxious based on the Goldberg Anxiety Scale. Fall concern did not affect the physiological and sway response to the elevated platform. In response to the postural threat, the anxious participants increased their sway frequency (p = 0.001) but did not reduce sway range (p = 0.674). Conversely, non-anxious participants showed an adaptive tightening of balance control, effectively reducing sway range in the elevated condition (p < 0.001). Generalised anxiety in older adults appears to differentially affect postural control strategies under threatening conditions.  相似文献   

4.
We implemented a virtual reality system to quantify differences in the use of visual feedback to maintain balance during walking between healthy young (n = 12, mean age: 24 years) and healthy old (n = 11, 71 years) adults. Subjects walked on a treadmill while watching a speed-matched, virtual hallway with and without mediolateral visual perturbations. A motion capture system tracked center of mass (CoM) motion and foot kinematics. Spectral analysis, detrended fluctuation analysis, and local divergence exponents quantified old and young adults’ dynamic response to visual perturbations. Old and young adults walked normally with comparable CoM spectral characteristics, lateral step placement temporal persistence, and local divergence exponents. Perturbed visual flow induced significantly larger changes in mediolateral CoM motion in old vs. young adults. Moreover, visual perturbations disrupted the control of lateral step placement and compromised local dynamic stability more significantly in old than young adults. Advanced age induces a greater reliance on visual feedback to maintain balance during waking, an effect that may compensate for degradations in somatosensation. Our findings are relevant to the early diagnosis of sensory-induced balance impairments and also point to the potential use of virtual reality to evaluate sensory rehabilitation and balance training programs for old adults.  相似文献   

5.
Human stability control is a complex process comprising contributions from several partly independent mechanisms such as coordination, feedback and feed-forward control, and adaptation. Acute alcohol intoxication impairs these functions and is recognized as a major contributor to fall traumas. The study aimed to investigate how alcohol intoxication at .06% and .10% blood alcohol concentration (BAC) affected the movement spans and control of posture alignment. The angular positions of the head, shoulder, hip and knees relative to the ankles were measured with a 3D motion analysis system in 25 healthy adults during standing with eyes open or closed and with or without vibratory balance perturbations.Alcohol intoxication significantly increased the movement spans of the head, shoulders, hip and knees in anteroposterior and lateral directions during quiet stance (p  .047 and p  .003) and balance perturbations (p < .001, both directions). Alcohol intoxication also decreased the ability to reduce the movement spans through adaptation in both anteroposterior (p  .011) and lateral (p  .004) directions. When sober and submitted to balance perturbations, the subjects aligned the head, shoulders, hip and knees more forward relative to the ankle joint (p < .001), hence adopting a more resilient posture increasing the safety margin for backward falls. Alcohol intoxication significantly delayed this forward realignment (p  .022). Alcohol intoxication did not cause any significant posture realignment in the lateral direction. Thus, initiation of adaptive posture realignments to alcohol or other disruptions might be context dependent and associated with reaching a certain level of stability threats.  相似文献   

6.
The authors investigate the ways in which varied postural responses to translating platform perturbations are associated with the variables of strength and power. Twenty-four physically active and 27 sedentary young adults were exposed to a set of postural perturbations at varied velocities (10 and 20 cm/s) and the respective accelerations (6.4 and 6.9 m/s2), constant distance (6 cm), and 4 directions of platform motion (forward, backward, left-lateral, and right-lateral). They also performed maximum voluntary isometric contraction (MVC) and chair rising/chair jumping tests. The analysis of variance revealed significant interaction effect for peak center of pressure displacement, direction by velocity: F3,129 = 24.43, p = .002; and direction by acceleration: F3,129 = 34.18, p = .001. There were no significant correlations between peak center of pressure displacements and peak force and peak rate of force development measured during MVC in either standing (r = .27–57) or sitting positions (r = .12–51) and peak power during chair jumping (r = .47–.59) in all participants. As such, only a small proportion of variance was explained (9–39%, 3–23%, and 23–41%, respectively). In conclusion, interaction effects indicate that the composition of stimuli strongly influences compensatory responses and this effect is more pronounced in sedentary than in physically active young adults. Nevertheless, the dynamic balance is not associated with muscle strength and power in either group.  相似文献   

7.
ObjectivesTo assess the effects of voluntarily reducing postural sway on postural control and to determine the attention level needed to do so in healthy adults (n = 16, 65.9 ± 9.7) and persons with PD (n = 25, 65.8 ± 9.5 years). Tasks: quiet and still standing conditions with and without a category task. Cognitive performance, center of pressure (CoP) displacement variability (RMSCoP) and velocity (VCoP) were assessed in the anterior-posterior (AP) and medial-lateral (ML) directions.Controls showed larger RMSCoP (AP) and VCoP (AP and ML) during still versus quiet standing (p < 0.01), while the PD group demonstrated no changes. In the PD group, RMSCoP and VCoP (ML) increased in still standing when performed with the cognitive task (p < 0.05). In both groups, cognitive responses decreased in still standing (p < 0.05).In PD, attempting to reduce postural sway did not affect postural control under single task conditions, however ML CoP variability and velocity did increase as a dual task. In older adults, increased displacement and velocity in both AP and ML directions was observed during single, but not dual task conditions. Therefore standing still might not be an adequate postural strategy as it increases the attentional demand and affects motor performance, putting persons with PD at greater risk for falls.  相似文献   

8.
ObjectiveTo study the influence of prolonged wearing of unstable shoes on standing postural control in prolonged standing workers.MethodsThe participants were divided into two groups: one wore unstable shoes while the other wore conventional shoes for 8 weeks. Stabilometry parameters related to centre of pressure (CoP), rambling (RM) and trembling (TR) as well as the total agonist/antagonist muscle activity, antagonist co-activation and reciprocal activation were evaluated during upright standing, before and after the 8 weeks period. In both moments, the subjects were evaluated wearing the unstable shoes and in barefoot.ResultsThe unstable shoe condition presented increased CoP displacement related variables and decreased co-activation command compared to barefoot before and after the intervention. The prolonged wearing of unstable shoes led to: (1) reduction of medial–lateral CoP root mean square and area; (2) decreased anteroposterior RM displacement; (3) increased anteroposterior RM mean velocity and mediolateral RM displacement; (4) decreased anteroposterior TR RMS; and (5) increased thigh antagonist co-activation in the unstable shoe condition.ConclusionThe unstable shoe condition is associated to a higher destabilising effect that leads to a selection of more efficient and accurate postural commands compared to barefoot. Prolonged wearing of unstable shoes provides increased effectiveness and performance of the postural control system, while wearing of unstable shoes in upright standing, that are reflected by changes in CoP related variables and by a reorganisation of postural control commands.  相似文献   

9.
It is often suggested that early onset of disorders leads to higher severity and greater treatment refractoriness. Previous research has investigated whether there are clinical and demographic differences between groups of individuals who have experienced onset of obsessive-compulsive disorder (OCD) at an early or later age. Results suggest that individuals who report an early onset (EO) of the disorder report greater severity and persistence of symptoms. However, few studies have investigated whether there are differences in treatment response. The present study represents a preliminary investigation in the setting of a specialist OCD clinic. Analysis was undertaken using clinical records to investigate whether there were clinical differences and in response to cognitive-behavioural treatment (CBT) between individuals who developed OCD at an early (n = 22) or late (n = 23) age. No differences in treatment response between the groups were found. However, the EO group were rated as being more severe across a range of measures at start of treatment, and hence at end of treatment they remained more severe than the LO group. This has clinical implications, suggesting that more treatment sessions may be required for individuals who report an EO of symptoms.  相似文献   

10.
The purpose of this study was to examine the role of foot sole somatosensory information during reactive postural control. Twenty young adults (22.0 ± 1.4 y) participated in this study. Baseline skin sensitivity from the foot sole was assessed using Semmes-Weinstein monofilaments. Postural muscle responses, in the form of electromyographic (EMG) onset latencies and amplitudes, were then obtained while participants recovered their balance while standing on a moveable platform that could translate in either the forward or backward direction. Following these baseline measures, the participant’s foot soles were immersed in a 0–2 °C ice-water bath for 12 min followed by a 3 min re-immersion period. At the completion of foot cooling, foot sole sensitivity and postural muscle responses to the balance perturbations were re-assessed. Results indicated that the foot cooling protocol reduced foot sole sensitivity and remained reduced throughout the duration of the experiment (p < 0.001). The reduction in foot sole somatosensation resulted in the soleus EMG onset latency being delayed by 3 ms (p = 0.041) and the soleus and medial gastrocnemius EMG amplitudes increasing by 14–23% (p = 0.002–0.036) during the balance perturbation trials. While the magnitude of these results may suggest that foot cooling has a minor functional consequence on reactive postural control, it is likely that the results also reflect the ability of the central nervous system to rapidly adapt to situations with altered somatosensory feedback.  相似文献   

11.
ObjectiveExamine whether implementing an active lumbopelvic control strategy during high load prone lumbar extension exercises affects posterior extensor chain recruitment and lumbopelvic kinematics.MethodsThirteen healthy adults acquired an optimal active lumbopelvic control strategy during guided/home-based training sessions. During the experimental session electromyography was used to evaluate the activity of the posterior extensor chain muscles during high load trunk/bilateral leg extension exercises with/without application of the strategy. Video-analysis was used to evaluate thoracic/lumbar/hip angles.ResultsImplementing the active lumbopelvic control strategy decreased the lordotic angle during trunk (p = 0.045; −3.2°) and leg extension exercises (p = 0.019; −10°). The hip angle was solely affected during trunk extension (p < 0.001; +9.2°). The posterior extensor chain (i.e. mean of the relative activity of all muscles (%MVIC) was recruited to a higher extent (p = 0.026; +9%) during trunk extension exercises performed with active lumbopelvic control. Applying the strategy during leg extension exercises lead to less activity of longissimus thoracic (p = 0.015; −10.2%) and latissimus dorsi (p = 0.010; −4.4%), and increased gluteus maximus activity (p  0.001; +16.8%).ConclusionsWhen healthy people are taught/instructed to apply an active lumbopelvic control strategy, this will decrease the degree of lumbar (hyper)lordosis and this influences the recruitment patterns of trunk and hip extensors. Hence, the possible impact on predetermined training goals should be taken into account by trainers.  相似文献   

12.
ObjectiveThe aim of this study was to compare adherence to physical activity and sedentary behaviour recommendations within the 2011 Institute of Medicine Early Childhood Obesity Prevention Policies as well as screen time recommendations from the 2013 American Academy of Pediatrics for samples of infants in child care centres in Australia, Canada, and the United States (US).MethodsThis cross-sectional study used data from: the Australian 2013 Standing Preschools (N = 9) and the 2014–2017 Early Start Baseline (N = 22) studies; the 2011 Canadian Healthy Living Habits in Pre-School Children study (N = 14); and the American 2008 (N = 31) and 2013–2017 (N = 31) Baby Nutrition and Physical Activity Self-Assessment for Child Care (NAP SACC) trials. Data were compared on the above infant recommendations. Percentages were used to describe compliance to the recommendations and chi-square tests to determine whether compliance differed by country.ResultsChild care centres were most compliant (74%–95%) with recommendations to: provide daily indoor opportunities for infants to move freely under adult supervision, daily tummy time for infants less than 6 months of age, indoor and outdoor recreation areas that encourage infants to be physically active, and discourage screen time. Centres were least compliant (38%-41%) with adhering to recommendations to: limit the use of equipment that restricts an infant’s movement and provide education about physical activity to families. Compared with Canadian and US centres, Australian centres were less compliant (46%) with the recommendation to engage with infants on the ground each day, to optimize adult-infant interactions and to limit the use of equipment that restricts the infant’s movement. Canadian centres were less compliant (39%) with the recommendation to provide training to staff and education to parents about children’s physical activity. US centres were less compliant (25%–41%) with the recommendations to provide daily opportunities for infants to explore their outdoor environment, limit the use of equipment that restricts the infant’s movement and provide education to families about children’s physical activity.ConclusionsAssisting child care centres on limiting the use of equipment that restricts an infant’s movement, and providing education about children’s physical activity to families may be important targets for future interventions.  相似文献   

13.
The experiment was conducted to determine the influence of mirror movements in bimanual coordination during life span. Children, young adults, and older adults were instructed to perform a continuous 1:2 bimanual coordination task by performing flexion–extension wrist movements over 30 s where symmetrical and non-symmetrical coordination patterns alternate throughout the trial. The vision of the wrists was covered and Lissajous-feedback was provided online. All age groups had to perform 10 trials under three different load conditions (0 kg, .5 kg, 1.0 kg: order counterbalanced). Load was manipulated to determine if increased load increases the likelihood of mirror movements. The data indicated that the performance of the young adults was superior compared to the children and older adults. Children and older adults showed a stronger tendency to develop mirror movements and had particular difficulty in performing the non-symmetrical mode. This type of influence may be attributed to neural crosstalk.  相似文献   

14.
PurposeThis study evaluates the psychometric performance of the Japanese version of the Overall Assessment of the Speaker’s Experience of Stuttering for Adults (OASES-A), a comprehensive assessment tool of individuals who stutter.MethodsThe OASES-A-J was administered to 200 adults who stutter in Japan. All respondents also evaluated their own speech (SA scale), satisfaction of their own speech (SS scale) and the Japanese translation version of the Modified Erickson Communication Attitude scale (S-24). The test-retest reliability and internal consistency of the OASES-A-J were assessed. To examine the concurrent validity of the questionnaire, Pearson correlation was conducted between the OASES-A-J Impact score and the S-24 scale, SA scale and SS scale. In addition, Pearson correlation among the impact scores of each section and total were calculated to examine the construct validity.ResultsThe OASES-A-J showed a good test-retest reliability (r = 0.81–0.95) and high internal consistency (α > 0.80). Concurrent validity was moderate to high (0.55–0.75). Construct validity was confirmed by the relation between internal consistency in each section and correlation among sections’ impact scores. Japanese adults showed higher negative impact for ‘General Information’, ‘Reactions to Stuttering’ and ‘Quality of Life’ sections.ConclusionThese results suggest that the OASES-A-J is a reliable and valid instrument to measure the impact of stuttering on Japanese adults who stutter. The OASES-A-J could be used as a clinical tool in Japanese stuttering field.  相似文献   

15.
Association studies between the NEO five factor personality inventory and COMT rs4680 have focused on young adults and the results have been inconsistent. However, personality and cortical changes with age may put older adults in a more sensitive range for detecting a relationship. The present study examined associations of COMT rs4680 and personality in older adults.Genetic association analyses were carried out between the NEO and the targeted COMT rs4680 in a large, well-characterized sample of healthy, cognitively normal older adults (N = 616, mean age = 69.26 years).Three significant associations were found: participants with GG genotype showed lower mean scores on Neuroticism (p = 0.039) and higher scores on Agreeableness (p = 0.020) and Conscientiousness (p = 0.006) than participants with AA or AG genotypes.These results suggest that older adults with higher COMT enzymatic activity (GG), therefore lower dopamine level, have lower Neuroticism scores, and higher Agreeableness and Conscientiousness scores. This is consistent with a recent model of phasic and tonic dopamine release suggesting that even though GG genotype is associated with lower tonic dopamine release, the phasic release of dopamine might be optimal for a more adaptive personality profile.  相似文献   

16.
Feedback delays in balance are often assessed using muscle activity onset latencies in response to discrete perturbations. The purpose of the study was to calculate EMG latencies in perturbed handstand, and determine if delays are different to unperturbed handstand. Twelve national level gymnasts completed 12 perturbed and 10 unperturbed (five eyes open and five closed) handstands. Forearm EMG latencies during perturbed handstands were assessed against delay estimates calculated via: cross correlations of wrist torque and COM displacement, a proportional and derivative model of wrist torque and COM displacement and velocity (PD model), and a PD model incorporating a passive stiffness component (PS-PD model). Delays from the PD model (161 ± 14 ms) and PS-PD model (188 ± 14 ms) were in agreement with EMG latencies (165 ± 14 ms). Cross correlations of COM displacement and wrist torque provided unrealistically low estimates (5 ± 9 ms). Delays were significantly lower during perturbed (188 ± 14 ms) compared to unperturbed handstand (eyes open: 207 ± 12 ms; eyes closed: 220 ± 19 ms). Significant differences in delays and model parameters between perturbed and unperturbed handstand support the view that balance measures in perturbed testing should not be generalised to unperturbed balance.  相似文献   

17.
To assess test-retest reliability scores on 16 balance tests of 21 individuals with Down syndrome whose ages ranged from 5 to 31 yr., participants performed a standing test on firm and soft surfaces with the eyes open and closed, the balance subset of the Bruininks-Oseretsky test, full turn, timed-up-and-go test, forward reach, and sit-to-stand. Each participant completed all 16 tests twice in one day and then again on a subsequent day for a total of 4 sessions. The interclass reliability correlation coefficients (ICC) value for each measure of balance varied considerably by age and sex. Based on having an ICC > .50, only 3 tests were reliable in young males and young females, whereas 5 tests could reliably be used in adult females and 9 tests could reliably be used in adult males. The results of this study raise suspicions as to the reliability of tests commonly used to assess balance and differences in reliability due to age and sex. Results of balance tests should be interpreted with caution in males and females with Down syndrome across the age span.  相似文献   

18.
The present study investigates the relationships between hippocampal corticosterone concentrations and memory retrieval performance in stress and non-stress conditions, in both young (6 month-old) and middle-aged (16 month-old) mice. For this purpose, the time-course evolution of stress-induced corticosterone rise in the dorsal hippocampus (dHPC) was investigated in both young and middle-aged mice. In parallel, the evolution of memory retrieval patterns was assessed using a contextual serial discrimination task (CSD). Finally, metyrapone (corticosterone synthesis inhibitor) was administered in order to evaluate the stress-induced impact of corticosterone rise on contextual memory retrieval in middle-aged animals.Results showed that: (i) non-stressed middle-aged mice exhibited a memory retrieval pattern opposite to that of non-stressed young animals, but similar to that of stressed young mice; (ii) the impact of stress on memory performance was transient (90 min) in young, as compared to middle-aged mice (120 min); (iii) dHPC basal (non-stress) corticosterone level was significantly increased by ageing; (iv) acute stress induced a rapid (15 min) and transient (90 min) dHPC corticosterone rise in young mice, while exhibiting greater magnitude and duration (120 min) in middle-aged animals; and (v) both the stress-induced endocrinal and memory effects were blocked by metyrapone in young and middle-aged mice.Finally, to our knowledge, the present work is the first study to directly measure the corticosterone rise in the hippocampus following exposure to stress and to directly correlate the corticosterone changes in the hippocampus with memory performance in both young and middle-aged mice.  相似文献   

19.
Currently, only two motor tests have norms extending into young adulthood – the McCarron Assessment of Neuromuscular Development (MAND, McCarron 1997) and the Bruininks Oseretsky Test of Motor Proficiency-2 (BOT-2, Bruininks & Bruininks, 2005). Research into the motor difficulties in early adulthood and health outcomes has been impeded because there is no agreed gold standard motor test for this group. The purposes of this study were to compare the discrimination accuracy, classification agreement, and predictive values, and gender distribution and prevalence of each test in identifying motor impairment (MI) in relation to DSM-V diagnostic criteria for DCD. Ninety-one young, healthy adults (M = 21.4 years, SD = 3.3) were recruited. Those classified as MI by each test scored at one standard deviation or more below the overall mean standard score. Small, statistically significant correlations were found between the MAND and BOT-2 SF tests for score rank (r = 0.370, p = 0.01) and standard score values (r = 0.404; p = 0.01). The overall decision agreement for non-MI cases was relatively high at 85% but very low for MI cases (4.4%). Unexpectedly, gender was balanced in MI cases. BOT-2 SF identified twice as many MI cases than MAND (13.2% vs 6.6%), yet overall comparative test specificity was high (89%). Predictive values for MAND, compared against BOT-2 SF as the standard, indicated broad independence between these tests and overall, the decision statistics indicated that the two tests identified different adult cohorts with MI. Objective classification of adult motor proficiency using a gold standard assessment tool including complex and ecologically valid tasks is still elusive.  相似文献   

20.
This study assessed the effects of vision and cognitive load on anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) in response to an externally triggered postural perturbation. A ball-hitting test was repeated under different visual conditions (eyes open, EO; eyes closed, EC) and cognitive loads (no load, 3-subtraction task, time-limited 3-subtraction task). Data were collected separately for I) surface electromyography from the right side of the biceps brachii (BIC) and erector spinae (ES) to detect the latency and response intensity (RI); and II) displacement of the centre of pressure (ΔCOP) to detect the standard deviation (ΔCOPSD) and maximum value (ΔCOPmax) in the anterior-posterior direction. Compared with the results under the EC condition, the ES latency was shorter and the RI of the BIC was lower under the EO condition. Accordingly, the ΔCOPSD and ΔCOPmax were increased in the APAs phase and decreased in the CPAs phase. Cognitive load had no effect on APAs and CPAs or on ΔCOP in the APAs phase. However, ΔCOPmax was decreased in the CPAs phase during the EC condition. In conclusion, vision played an important role in APAs and CPAs for muscle activation and ΔCOP. Cognitive load had no effect on neuromuscular APAs or CPAs except when the postural perturbation occurred when visually unexpected.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号