13 research outputs found
Acute effects of static and dynamic stretching on jump performance after 15 min of reconditioning shooting phase in basketball players
No full text2016-09-15. Effects of long term stimulation of textured insoles on postural control in health elderly. In JOURNAL OF SPORTS MEDICINE AND PHYSICAL FITNESS - ISSN:0022-4707
Annino, G; Palazzo, F; Alwardat, M; Manzi, V; Lebone, P; Tancredi, V; Sinibaldi Salimei, P; Caronti...
Resp. del dato :
GIUSEPPE ANNINO
Identificativo :
hdl:2108/164271
01 - Articolo su rivista validato errore 10/11/2016 12:37 Sito docente: Success
Effects of stimulating surface during static upright posture in the elderly
No full textThis study aimed to investigate the influence of three stimulating surfaces based on center of pressure (CoP), anteroposterior sway velocity (VA/P), and medio-lateral sway velocity (VM/L) of 40 elderly subjects. CoP and VM/L showed a significant decrease in all visual conditions only in the stimulating surface whereas VA/P showed a significant decrease only on the same surface with eyes open. Results confirm the importance of multisensory stimulation in postural control in the elderly
Slopes And Speed Related Effects On Kinematic And Emg Patterns In Elite Race Walking.
No full textIntroduction. In human locomotion every external condition generates a strategy. The aim of this study is to analyze the kinematics parameters and to indentify the changes in movement pattern and muscle activity of race-walkers (RW). Methods. Twelve elite RW have race walking on a treadmill for 5 minutes each slope (0, 2 and 7%) in iso-efficiency speed (IES1) with heart rate and sEMG on leg muscles constantly monitored. Digital cameras (210 Hz) were used to record; Dartfish 5.5Pro was used to perform a 2D video analysis, while for statistical analysis was used Anova. (1) The IES (km/h) for each subject at 0% grade was the average speed during the best performance in the 10000 m race, minus 1 km/h, which corresponds to the ~50% Vo2MAX and requires an energy cost (Cw0) of 5.0 J/m/kg according to previous studies (Di Prampero 1986). Moreover, according to previous data (Minetti et al. 2002) the increase of Cw as a function of ground slope is: 0.15 * slope (%) + Cw0. We calculated for each ground slope the IES at which the Vo2 was equal to the oxygen consumption during level race walking using the following equation: Vo2= (Cw0/21(J/m) * (IES0/0.06 (m/min)) IES= (Vo2 * 21 * 0.06)/(0.15(Cw) * slope (%) + (Cw0)) Results IES, step length (SL) and frequency (SF) decrease as a function of the increasing slope: IES0 12.5 – IES2 11.8 – IES7 10.3; SL= (0-2%= -3.71%, n.s.; 0-7%= -12.23%, p<0.001); SF= (0-2%= -2.38%, n.s.; 0-7%= -6.07%, p<0.01). The contact time (CT) and heart rate (HR) increase at the increasing slope: CT= (0-2%= 2.46%, n.s.; 0-7%= 6.56%, p<0.01); HR= (0-2%= 0.62%, n.s.; 0-7%= 3.25%, p<0.05). The sEMG activity was reduced at the increasing slope in: tibialis anterior (0-2%= 22.49%, p<0.0001; 0-7%= 41.18%, p<0.0001); rectus femoris (0-2%= 15.35%, p<0.0001; 0-7%= 29.13%, p<0.0001). While the sEMG activity was increased in this muscles: vastus lateralis (0-2%= 22.95%, p<0.0001; 0-7%= 31.15%, p<0.0001); gastrocnemius medialis (0-2%= 21.40%, p<0.001; 0-7%= 48.37%, p<0.0001); biceps femoris (0-2%= 190.78%, p<0.0001; 0-7%= 201.37%, p<0.0001). Discussion. These results provide the resultant of the real mechanical work in different slopes without increasing energetic cost, validating the equation to calculate the speed in RW only at IES between zero and 2% gradient. While for higher gradient levels the procedure used in this study seems to overestimate the speed, probably due to the different biomechanics between walking (Minetti et al., 2002) and race walking. References Di Prampero PE. The energy cost of human locomotion on land and in water. (1986). Int J Sports Med, 7 (2), 55-72. Minetti AE, Moia C, Roi GS, Susta D, Ferretti G. Energy cost of walking and running at extreme uphill and downhill slopes. (2002). J Appl Physiol, 93(3),1039-1046
The efficacy of plantar stimulation on human balance control
No full textAim: The aim of this study was to evaluate the body sway using firm, foam, and firm textured
surfaces on 17 young adults. Method: Displacement of center of pressure (CoP), anteroposterior
velocity (VA/P), and mediolateral velocity (VM/L) were measured. Data: The data showed a
significant decrease of CoP, VA/P, and VM/L between support surfaces and vision. Results:
The results showed that, differently from the firm and foam, the textured surface is able to
increase the plantar feedback to maintaining postural control
Effects of long term stimulation of textured insoles on postural control in health elderly
No full textBackground: The aim of this study was to confirm the effects of long term (chronic) stimulating surface (textured insole) on body balance of elderly people.
Methods: Twenty-four healthy elderly individuals were randomly distributed in two groups: control and experimental (67.75 ± 6.04 yrs, 74.55±12.14 kg, 163.7 ± 8.55 cm, 27.75 ± 3.04 kg/m2). Over one month, Control Group (CG) used smooth insoles and the Experimental Group (ExG) used textured insoles every day.
Velocity net (Vnet), anteroposterior (VA/P), mediolateral (VM/L) and sway path of CoP were assessed in different eye conditions before and after the experimental procedure.
Results: A mixed between-within subject ANOVA was conducted to assess the impact of soft and textured insoles and two visual conditions (vision vs no vision) across two time periods (α ≤ 0.05). The results showed any statistical difference between groups in each parameter assessed in this study. CoP, Vnet and VM/L in the experimental group showed a statistically significant effect of textured insoles only without vision (CoP: P= 0.002; η2=0.35), Vnet P=0.02; η2=0.24, VM/L P=0.04; η2=0.177) whereas VA/P showed no statistically significant effect in the same group and condition. There was no significant effect in Vnet, VA/P, VM/L and COP in control group that used smooth insole for both eye conditions.
Conclusions: The results confirm that postural stability improved in healthy elderly individuals, increasing somatosensory information's from feet plantar mechanoreceptors. Long term stimulation with textured insoles decreased CoP, Vnet and VM/L with eyes closed
Effect of textured insoles on postural control during static upright posture following lower limb muscle fatigue
No full textThe purpose of this study was to assess the effects of textured insoles on static upright posture before and after lower limb muscle fatigue. Textured insoles used contained small and non-deformable pebbles of various sizes that are able to stimulate a major number of mechanoreceptors. It was inserted inside footwear
Water versus land-based exercises as physical training programs in elderly
No full textThe study aims to analyze and quantify the improvements of some physical skills in a group of subjects over 65 years old who practice regular activities in the gym and in a microgravity environment
Chemically derived ziconia toughened alumina via sol-gel processing, 1997
No full textSol-gel processing methods were used to prepare ZTA ceramic powders from high purity materials. The precursor systems used for this research were zirconium butoxide, zirconium isopropoxide, alumium tri-sec butoxide, and yttrium isopropoxide. Other reagents were also used. The emphasis was on mixing the precursor system, performing aging experiments, and heat treatment studies to prepare the final ZTA ceramics. The effects of processing conditions on the sol to gel transition were examined by varying the water ratios, the ZTA precursor composition and the molar ratio of TEA/alkoxide. It was observed that the TEA/alkoxide molar ratio played an important role in the time for gel formation. The presence of poorly hydrolyzable ligands slows down the hydrolysis condensation process. The total amount of water for hydrolysis had an effect on the time of gel-formation. Rheological measurements made during the aging process indicated an increase in viscosity with aging time, which was consistent with changing structure. XRD was used to determine the phase composition after heat treatment. From XRD diagram, alumina is transformed into the a phase after calcination at 1200�C, the tetragonal 7I02 phase was retained on cooling to room temperature in the mixture containing. TG/DTA was also used to deteramine optimum heating schedules. In the presene of zirconia, the alumina phase transformation takes place at a considerably higher temperature than in pure alumina, the more volume percent of Z1O2, the higher the transformation temperature
Oxide/oxide mijlltte composites derived via sol-gel processing, 1998
No full textSol-gel processing methods were used to prepare mullite ceramic powders from high purity materials. The mullite precursors used for this research were aluminum tri-sec butoxide as the alumina precursor and tetraethylorthosilicate as the silica precursor. The effects of processing conditions on the sol to gel transition were examined by varying i) the type of catalyst used and ii) the type of chelating agent used. Prehydrolysis of the Tetraethylorthosilicate (TEOS) was used since the aluminum tri-sec butoxide (ATSB) reacts faster than the TEOS. In addition to prehydrolyzing TEOS, ATSB was stabilized using the chelating agents, ethylacetoacetate (EAA) or triethanolamine (TEA) to slow the reaction rate of the ATSB with water. It was observed that the mullite precursors prepared with EAA all rendered white powders upon heat-treatment. Commercially available silica and alumina powders were also used to prepare mullite powder. Fourier transform infrared (FTIR) spectra of the acid and base catalyzed mullite powders showed no significant differences. FTIR spectra of the commercial alumina and silica powder used to prepare mullite indicate the presence of pure alumina which indicated phase separation at the micro-scale level. This result was verified by X-ray diffraction (XRD). Thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) curves for both the acid and base catalyzed mullite precursor dried gels showed that mullitization occurs at approximately 1000C. XRD diffractograms of the acid and base catalyzed powders correlated well with the mullite reference pattern. Mullite fiber reinforced mullite composites were fabricated using the hot-press technique. Nextel 720 mullite fibers were used as the reinforcing fibers. Scanning electron microscopy (SEM) was used to examine a) the grain sizes of the mullite powders and mullite fiber reinforced composites, b) pinpoint fibers present in the mullite composite and c) the interfacial bonding between the mullite and the mullite fiber. In all cases, fine grain mullite powders were obtained prior to hot-pressing. As the powders were embedded with fibers and hot-pressed at higher temperatures, some of the grains of the powders fused together. At lower magnifications it was very difficult to pinpoint fibers in the matrix. As the magnification increased, fibers were seen distributed throughout the matrix; indicating good fiber/ matrix interaction in some regions of the sample. Due to hot-pressing conditions and preparation, it was difficult to determine exact grain sizes and fiber locations in the composites
