The study investigated whether anticipatory postural adjustments (APAs) of gait initiation and kinematics of the first step are modified with absence of vision in relation to age. Twenty-two young and twenty-two older subjects initiated a self-paced gait with the vision available and deprived. APAs were measured by: (1) force platform and evaluated by maximal amplitude of the center of pressure (CoP) displacements; (2) two inertial sensors attached to the trunk and evaluated by maximal accelerations. Step kinematics was recorded using a motion capture system and evaluated by duration, length and maximal velocity of the first step. Visual deprivation led to a significant reduction of forward trunk accelerations during the anticipatory phase of stepping in older adults. Moreover, they significantly reduced first step length and maximal velocity and prolonged duration of the first step. Contrary, young adults did not respond to absence of vision by significant changes of neither APAs, nor first step kinematics. These findings suggest that gait initiation is strongly associated with increased reliance on vision in older adults. We further indicate that trunk accelerations during the anticipatory phase of stepping may be a more sensitive measure to detect age-related changes of APAs due to absent visual information compared to CoP.
- MeSH
- analýza chůze MeSH
- biomechanika MeSH
- časové faktory MeSH
- chůze (způsob) * MeSH
- dospělí MeSH
- fyziologická adaptace MeSH
- lidé MeSH
- podněty MeSH
- postura těla * MeSH
- posturální rovnováha * MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- stárnutí MeSH
- věkové faktory MeSH
- zrak * MeSH
- zraková percepce * MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The study is aimed to examine balance control of slightly obese young adults during quiet stance and during gait initiation with and without crossing an obstacle. Forty-four young subjects were divided in two groups: control (BMI<25 kg/m(2)) and slightly obese (BMI from 25 to 35 kg/m(2)). Center of foot pressure (CoP) and kinematics of fifth lumbar vertebra (L5) were evaluated using a force plate and a motion capture system. During quiet stance with eyes open slightly obese group showed increased mean amplitude and velocity of CoP in anterior-posterior direction compared to normal weight subjects. During unloading phase of gait initiation significantly greater and faster lateral CoP shift was observed in slightly obese group compared to normal weight peers. Presence of an obstacle increased amplitude and velocity of the lateral CoP shift similarly in both groups. No BMI-related differences were found on L5 segment during gait initiation, which may indicate that postural control was already successfully performed in feet (CoP). We have shown that increased CoP parameters values and thus increased postural instability during quiet stance and during unloading phase of gait initiation is present not only in morbidly obese, but already in slightly obese subjects.
The aim of this study was to determine whether respiration would be altered during visual biofeedback condition while standing on a foam surface. Fifty young, healthy subjects (24 men, 26 women) were divided into a spirometry group, in which additional spirometry analysis was performed, and a control group. All subjects were tested in two conditions: 1) standing on a foam surface and 2) standing on a foam surface with visual biofeedback (VF) based on the centre of pressure (CoP). CoP amplitude and velocity in anterior-posterior (Aap, Vap) and medial-lateral (Aml, Vml) directions were measured by the force platform. Breathing movements were recorded by two pairs of 3D accelerometers attached on the upper chest (upper chest breathing - UCB) and the lower chest (lower chest breathing - LCB). Results showed that significant decreases of CoP amplitude and velocity in both directions were accompanied by a significant decrease of lower chest breathing, and an increase of LCB frequency was seen during VF condition compared to control condition in both groups. Moreover, a significant decrease in tidal volume and increased breathing frequency during VF condition were confirmed by spirometric analysis. Reduced breathing movements and volumes as well as increased breathing frequency are probably part of an involuntary strategy activated to maximize balance improvement during VF condition.
- MeSH
- akcelerometrie MeSH
- dospělí MeSH
- dýchání * MeSH
- lidé MeSH
- mechanika dýchání MeSH
- mladý dospělý MeSH
- posturální rovnováha * MeSH
- senzorická zpětná vazba * MeSH
- spirometrie MeSH
- světelná stimulace MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
