Search results for "post"
showing 10 items of 6213 documents
Postural Sway During Standing and Unexpected Disturbance of Balance in Random Samples of Men of Different Ages
1985
Postural sway behavior while standing and during and after an unexpected disturbance of balance was examined in men aged 31 to 35, 51 to 55, and 71 to 75 years. The groups studied were random samples of men living in the town of Jyväskylä in 1981. Postural sway while standing was more pronounced in the older age groups, whereas after a disturbance of balance postural sway was nearly the same in all age groups. The functioning of the postural control system was correlated with the vibratory threshold on the ankles, grip strength, as well as with aerobic and anaerobic capacity within the age groups. Further, in the youngest age group the functioning of the postural control system was poorer a…
Reaction and Movement Times in Men of Different Ages: A Population Study
1986
Tests of psychomotor and motor speed at different levels of complexity were studied in random samples of men aged 31 to 35, 51 to 55, and 71 to 75 yr. The study was performed as a part of a larger research project on health and functional aging. Analyses indicated significantly slower responses among older men at all levels of test complexity (maximal knee extension velocity, tapping rate, simple and choice reaction and movement times). There were marked differences both between the youngest and the middle-aged groups and between the middle-aged and the oldest groups. Within the age groups high psychomotor and motor speed were associated with a favourable functioning of certain senses (vib…
Application of intermittent galvanic vestibular stimulation reveals age-related constraints in the multisensory reweighting of posture
2014
In this study we examined the effects of intermittent short-duration Galvanic Vestibular Stimulation (GVS) during a multisensory perturbation of posture in young and elderly adults. Twelve young (24.91 +/- 6.44 years) and eleven elderly (74.8 +/- 6.42 years) participants stood upright under two task conditions: (a) quiet standing and (b) standing while receiving pseudo-randomly presented bipolar 2 s GVS pulses. In both conditions, sensory reweighting was evoked by visual surround oscillations (20 cm, 0.3 Hz) and Achilles tendon vibration (3 mm, 80 Hz), concurrently delivered during the middle 60 s of standing. Intermittent GVS decreased the excessive postural sway induced by the concurrent …
Maximal and explosive force production capacity and balance performance in men of different ages
1999
A group of 32 healthy men (M) divided into three different age groups, i.e. M20 years [mean 21 (SD 1); n = 12], M40 [mean 40 (SD 2); n = 10] and M70 [mean 71 (SD 5); n = 10] volunteered as subjects for examination of maximal and explosive force production of leg extensor muscles in both isometric and dynamic actions (squat jump, SJ and counter movement jump, CMJ, and standing long-jump, SLJ). The balance test was performed on a force platform in both isometric and dynamic actions. Maximal bilateral isometric force value in M70 was lower (P < 0.001) than in M40 and as much as 46% lower (P < 0.001) than that recorded in M20 (P < 0.001). The maximal rate of force development (RFD) on the force…
Factors associated with maximal walking speed among older community-living adults.
2011
Background and aims: The relative contribution of different domains on walking speed is largely unknown. This study investigated the central factors associated with maximal walking speed among older people. Methods: Cross-sectional analyses of baseline data from the SCAMOB study (ISRCTN 07330512) involving 605 community-living ambulatory adults aged 75–81 years. Maximal walking speed, leg extensor power, standing balance and body mass index were measured at the research center. Physical activity, smoking, use of alcohol, chronic diseases and depressive symptoms were self-reported by standard questionnaires. Results: The mean maximal walking speed was 1.4 m/s (range 0.3–2.9). In linear regre…
Balance control interferes with the tracing performance of a pattern with mirror-reversed vision in older persons
2014
When tracing a template with mirror-reversed vision (or distorted vision), the sensory information arising from the movement does not match the expected sensory consequences. In such situations, participants have to learn a new visuomotor mapping in order to trace the template with an accuracy and speed approaching that observed when tracing with direct vision. There are several suggestions that such visuomotor learning requires lowering the gain of the proprioceptive inputs. Generally, subjects learn this task in a seated condition offering a stable postural platform. Adapting to the new visuomotor relationship in a standing condition could add complexity and even hinder sensorimotor adapt…
Technical determinants of biathlon standing shooting performance before and after race simulation
2018
The aim of this study was to identify performance- determining factors in biathlon standing shooting in rest and after intense exercise. Eight Finnish national- and nine junior- team biathletes participated in the study. Participants fired 40 resting shots (REST) and 2 × 5 competition simulation shots (LOAD) after 5 minutes of roller skiing at 95% of peak heart rate. Hit percentage, aiming point trajectory and postural balance were measured from each shot. Cleanness of triggering (ATV, movement of the aiming point 0- 0.2 second before the shot) and vertical stability of hold (DevY) were the most important components affecting shooting performance both in REST (DevY, R = −0.61, P < .01; ATV,…
Longterm Risk of Solid Organ De Novo Malignancies After Liver Transplantation: A French National Study on 11,226 Patients
2018
IF 3.756; International audience; De novo malignancies are one of the major late complications and causes of death after liver transplantation (LT). Using extensive data from the French national Agence de la Biomédecine database, the present study aimed to quantify the risk of solid organ de novo malignancies (excluding nonmelanoma skin cancers) after LT. The incidence of de novo malignancies among all LT patients between 1993 and 2012 was compared with that of the French population, standardized on age, sex, and calendar period (standardized incidence ratio; SIR). Among the 11,226 LT patients included in the study, 1200 de novo malignancies were diagnosed (10.7%). The risk of death was app…
The difficulty of the postural control task affects multi-muscle control during quiet standing
2016
The aim of this study was to compare the electromyographic (EMG) coherence between the lower limb and the core muscles when carrying out two postural tasks at different difficulty levels. EMG was recorded in 20 healthy male subjects while performing two independent quiet standing tasks. The first one involved a bipedal stance with the eyes open, while the second consisted of a dominant unipedal stance also with the eyes open. The obtained EMG signals were analysed by computing estimations of EMG–EMG coherence between muscle pairs, both singly (single-pair estimations) and combined (pooled estimations). Pooled and single coherence of anterior, posterior, core, antagonist and mixed pairs of m…
Instability training, assessing the impact of level of difficulty on balance: A randomized clinical trial
2018
Background: Most human movements are executed while in a state of postural instability. For this reason, instability training is a highly-specific method that is intended to improve balance and postural control. This research aimed to determine the effect of instability training on the balance of individuals with similar baseline abilities, who initiated training within different stability conditions. Research question: Does the level of difficulty with which instability training is performed determine improvements in balance? Method: A two-arm randomized trial was undertaken, for which 22 and 21 participants were included in the experimental and control groups, respectively. The experiment…