Search results for "Move"
showing 10 items of 2153 documents
Neuromuscular performance and body mass as indices of bone loading in premenopausal and postmenopausal women.
2009
The strong association between body mass and skeletal robusticity has been attributed to increasing skeletal loading with increasing mass. However, it is unclear whether body mass is merely a coarse substitute for bone loading rather than a true independent predictor of bone strength. As indices of neuromuscular performance, impulse and peak power were determined from vertical ground reaction force during a maximal counter movement jump test in 221 premenopausal and 82 postmenopausal women. Bone compressive (BSI(d) g(2)/cm(4)) and bending (SSImax(mid) mm(3)) strength indices were measured with peripheral quantitative computed tomography (pQCT) at the distal ((d)) and midshaft ((mid)) sites …
Magnetic resonance imaging of postrepair-myelomeningocele — findings in 31 children and adolescents
1987
Magnetic resonance imaging has clearly demonstrated its efficacy in the diagnosis of pathological processes in the C.N.S. We examined 31 children who had undergone plastic closure of myelomeningocele a few days post partum. We could show that a high percentage of the patients (89%) presented the pathological anatomy of a tethered spinal cord; clinical symptoms of the tethered spinal cord syndrome, i.e. progressive neurological symptoms, however, are rarely observed. Possible revision of neurosurgical treatment of MMC is discussed.
Quantifying the contribution of arm postural tremor to the outcome of goal-directed pointing task by displacement measures.
2004
A method for quantifying the outcome of goal-directed postural pointing was presented and used for relating the tremor output to the oscillations of single arm landmarks. The displacement of reflective markers placed on shoulder, upper arm, forearm, and hand were measured by an optoelectronic motion capture system in nine subjects holding a laser penlight pointed at a target. The high signal-to-noise ratio of the measured displacement series (from 7:1 for shoulder marker to 30:1 for hand marker) demonstrated the feasibility of the proposed system to carry out tremor analysis. The track of the laser emission on the target, reconstructed from penlight displacements, was studied as the outcome…
Neuromuscular fatigue induced by a 90-minute soccer game modeling.
2012
This study aimed to quantify neuromuscular fatigue induced by a soccer game. Eight amateur soccer players (age 20.4 ± 1.3 years, mass 70.4 ± 6.9 kg, and height 174.9 ± 5.2 cm) reproduced a 90-minute soccer game modeling composed of two 45-minute periods separated by a 15-minute rest. Torque of quadriceps and hamstring muscle groups associated with electromyography, sprint speed, and vertical jump height was assessed before, at halftime, and immediately after the modeling. Most physical qualities decreased throughout the game with greater decays at match end than at halftime. Contrarily to quadriceps muscles, hamstring torque impairments were not accompanied by electromyographic activity red…
The effects of assisted and resisted plyometric training on jump height and sprint performance among physically active females
2021
The aim of the present study was to compare the effects of assisted and resisted plyometric jump training on jump height, sprint performance (acceleration (0-20m), maximum speed (30-40m) and 40m sprint time) among physically active females. Fifty-six participants (age: 21.1 ± 1.7 years; body mass: 64.2 ± 7.0 kg; height: 168.0 ± 5.6 cm) were randomly allocated to either an assisted (n = 16) or resisted training group (n = 17), or a control group (n = 14). Nine participants dropped out during the intervention. The training sessions consisted of three different plyometric jump exercises over an eight-week period, while the control group continued their normal training routine. The results reve…
Eye position tunes the contribution of allocentric and egocentric information to target localization in human goal-directed arm movements.
1997
Subjects were required to point to the distant vertex of the closed and the open configurations of the Muller-Lyer illusion using either their right hand (experiment 1) or their left hand (experiment 2). In both experiments the Muller-Lyer figures were horizontally presented either in the left or in the right hemispace and movements were executed using either foveal or peripheral vision of the target. According to the illusion effect, subjects undershot and overshot the vertex location of the closed and the open configuration, respectively. The illusion effect decreased when the target was fixated and when the stimulus was positioned in the right hemispace. These results confirm the hypothe…
Deafferentation and pointing with visual double-step perturbations
1999
The capability of reprogramming movement responses following changes in the visual goal has been studied through the double-step paradigm. These studies have shown that: (a) continuous internal feedback-loops correct unconsciously the dynamic errors throughout the movement; (b) proprioceptive information and/or the efference copy have a privileged status among central processes, insuring on-line regulation of the initial motor commands; and (c) generation of the motor program starts after target presentation, and is continuously updated in the direction of the current internal representation of the target, at least until the onset of hand movement. This main corrective process of the initia…
Age Differences in Learning from Instructional Animations
2015
Summary: The present study tests the effects of the decline of executive functions and spatial abilities with aging on the comprehension of a complex instructional animation. An animation of a piano mechanism was presented individually to 33 young adults and 31 elderly participants. Two presentation speeds of the animation (normal and slow) were compared in a 2×2 experimental design. Eye movements were recorded during the learning time. Then, four executive function tests (inhibition, shifting, updating, and processing speed) and a spatial ability test (differential aptitude test) were undertaken by each participant. Results showed that the comprehension of animations was significantly affe…
Postural balance and health-related factors in middle-aged and older women with injurious falls and non-fallers.
2004
Background and aims: Older jailers aged over 70 years have shown impaired balance abilities, but it is unclear if impairment in balance control can be detected among jallers who are in their 50’s and 60’s. The aim oj this study was to analyze possible differences in balance control and other health-related factors between female fallers and nonfallers aged 50–68 years. Methods: Women 50–68 years of age (N=40) who had fallen outside and needed medical attention were recruited through a larger fall accident study. Non-fallers (N=97) were women representing the same age group who had not fallen during the preceding 12 months. A battery of standing force platform balance tests were administered…
Genetic and environmental contribution to postural balance of older women in single and dual task situations
2005
Abstract The purpose of the present study was to examine the effect of a second task on postural balance and to determine the role of genetic influences on postural balance when dual tasking among 206 monozygotic and 227 dizygotic female twins, aged 63–76 years. Balance was measured as medio-lateral and antero-posterior velocity of the centre of pressure (COP) (mm/s) and velocity moment (mm2/s) while standing on a force platform. Doing an arithmetic task increased movement of the COP while the hand motor task had no effect on movement of the COP. The genetic contribution to balance in the single task situation was minor (14%, 95% confidence interval, CI: 11–35%) whereas in the dual task sit…