1,720,969 research outputs found
Tradizione versus innovazione. Analisi comparata del dispendio energetico tra una sequenza di passi eseguita su piattaforma stabile e su superficie instabile
No full textLocal stability and kinematic variability in walking and pole walking at different speeds
No full textThis study investigated the kinematic variability and the local stability of walking and pole walking using two tri-axial accelerometers placed on the seventh cervical (C7) and the second sacral (S2) vertebrae of twenty-one adults. Each participant performed three 1-min trials of walking and pole walking on a motorized treadmill (60, 80, 100% of the preferred walk-to-run transition speed). Forty strides per trial were used to calculate, in all directions of C7 and S2, the median of the stride-to-stride median absolute deviation (medMAD) and the local divergence exponent (λ). Generalised estimating equations and pairwise contrasts revealed, during pole walking, a higher medMAD (all directions, most speeds, C7 level only), and a lower λ (all directions, all speeds, both C7 and S2 level). As speed increased, so did medMAD (all directions, both walking with or without poles), with higher values at C7 compared to S2 level. A similar effect was observed for λ in the vertical direction (walking and pole walking), and in the anterior-posterior direction (only pole walking). An increase in speed brought about a λ reduction in the medial-lateral direction (C7 level only), especially during walking. Finally, both medMAD and λ were higher at C7 than S2 level (all directions, both walking and pole walking) except for λ in the anterior-posterior direction, which resulted higher in walking (C7 level only). In conclusion, despite a higher kinematic variability, pole walking appears to be more locally stable than walking at any speed, especially at C7 level
Walking vs. Nordic walking exercise: differences in trunk muscle activity and impact acceleration
No full textAttività motoria per il miglioramento dello stato di salute in carcere
No full textLa detenzione è stata associata ad una ridotta attività fisica. I detenuti sedentari hanno un sostanziale aumento del rischio di sviluppare diabete mellito, malattie cardiache e una serie di altre condizioni croniche invalidanti. Lo scopo del presente studio è stato quindi di valutare gli effetti di un programma di allenamento aerobico e di stretching su peso, IMC, circonferenza vita, circonferenza fianchi, rapporto vita-fianchi, fitness cardiorespiratorio (distanza al 6MWT), flessibilità ed equilibrio in 23 detenuti adulti sedentari. I risultati indicano che un programma di allenamento aerobico e di stretching della durata di tre mesi migliora significativamente il fitness cardiorespiratorio e l’equilibrio
Trunk muscles activation during pole walking vs. walking performed at different speeds and grades
No full textGiven their functional role and importance, the activity of several trunk muscles was assessed (via surface electromyography—EMG) during Walking (W) and Pole Walking (PW) in 21 healthy adults. EMG data was collected from the external oblique (EO), the erector spinae longissimus (ES), the multifidus (MU), and the rectus abdominis (RA) while performing W and PW on a motorized treadmill at different speeds (60, 80, and 100% of the highest speed at which the participants still walked naturally; PTS60, PTS80 and PTS100, respectively) and grades (0 and 7%; GRADE0 and GRADE7, respectively). Stride length, EMG area under the curve (AUC), muscles activity duration (ACT), and percentage of coactivation (CO-ACT) of ES, MU and RA, were calculated from the averaged stride for each of the tested combinations. Compared to W, PW significantly increased the stride length, EOAUC, RAAUC and the activation time of all the investigated muscles, to different extents depending on treadmill speeds and grades. In addition, MUAUC was higher in PW than in W at GRADE0 only (all speeds, p < 0.01), while ESAUC during W and PW was similar at all the speeds and grades. These changes resulted in longer CO-ACT in PW than W, at GRADE0-PTS100 (p < 0.01) and GRADE7 (all speeds, p < 0.01). In conclusion, when compared to W, PW requires a greater engagement of the abdominal muscles and, in turn, a higher control of the trunk muscles. These two factors taken together may suggest an elevated spinal stability while walking with poles
Patterns of trunk muscle activation during walking and pole walking using statistical non-parametric mapping
No full textThis study used surface electromyography (EMG) to investigate the regions and patterns of activity of the external oblique (EO), erector spinae longissimus (ES), multifidus (MU) and rectus abdominis (RA) muscles during walking (W) and pole walking (PW) performed at different speeds and grades. Eighteen healthy adults undertook W and PW on a motorized treadmill at 60% and 100% of their walk-to-run preferred transition speed at 0% and 7% treadmill grade. The Teager-Kaiser energy operator was employed to improve the muscle activity detection and statistical non-parametric mapping based on paired t-tests was used to highlight statistical differences in the EMG patterns corresponding to different trials. The activation amplitude of all trunk muscles increased at high speed, while no differences were recorded at 7% treadmill grade. ES and MU appeared to support the upper body at the heel-strike during both W and PW, with the latter resulting in elevated recruitment of EO and RA as required to control for the longer stride and the push of the pole. Accordingly, the greater activity of the abdominal muscles and the comparable intervention of the spine extensors supports the use of poles by walkers seeking higher engagement of the lower trunk region
La percezione fisica di sé negli scolari adolescenti: Ruolo della costituzione fisica e del livello di attività fisica
Full text linkLa percezione di sé è influenzata dalla costituzione corporea, dal sesso, e dall’esercizio fisico. Non è chiaro, però, se gli effetti dell’esercizio derivino dal livello di attività fisica praticata o dal miglioramento delle capacità fisiche che esso determina. Pertanto questo studio ha indagato l’effetto, sia del livello di attività fisica che delle capacità fisiche sulla percezione fisica di sé, in funzione del sesso e della costituzione corporea, in studenti adolescenti. Il livello generale delle capacità fisiche di 188 adolescenti tra i 12 ed i 16 anni è stato valutato tramite una batteria di test motori, il livello di attività fisica è stato misurato con il questionario Physical Activity Questionnaire for Adolescents, mentre la percezione fisica di sé è stata valutata con il questionario Physical Self-Description Questionnaire Short. L’effetto del sesso e della costituzione fisica sono stati indagati tramite analisi della varianza considerando come covariate il livello di attività fisica e le capacità fisiche. I risultati evidenziano che essere in sovrappeso diminuisce la considerazione fisica generale di sé. Inoltre, la percezione di sé dei maschi è generalmente più alta delle femmine anche se questa non corrisponde a più elevate capacità fisiche o ad un maggior livello di attività fisica
Effectiveness of exercise training in increasing ultrasound-mediated improvements in body composition – preliminary results
No full textUltrasound treatment is commonly used in aesthetic medicine as a non-surgical method to reduce localized fat deposits. Transdermal focused ultrasound waves cause adipocytes cell membrane destruction: this lead to the liberation of the cell content in the interstitial space which, in turn, may increase high-energy substrate availability in the bloodstream. High-energy substrate utilization is augmented by both aerobic and resistance exercise: fat is the major fuel during low-intensity aerobic exercise whereas resistance training increases post-exercise high-energy substrate utilization. Although ultrasound treatment has been proved to be a safe and effective method in reducing localized fat deposits, the possible adjunctive effects of aerobic and resistance exercises has never been studied. The aim of this study is to compare the effectiveness of combining exercise training and multiple ultrasound treatments (EU group) versus either exercise (E group) or ultrasound (U group) interventions alone.
Sixteen young female subjects were randomly assigned to the EU (n=9; 29.3±3.8yr) and the U (n=7; 32±4.9yr) groups, while the recruitment of the E group is still in progress. Intervention of the EU group consisted in 10 ultrasound treatments (1/wk) plus combined walking and resistance training (2/wk x 10 wks). U group intervention was identical but restricted to the ultrasound treatments. Before (t0) and after (t1) the intervention, subjects underwent the following measurements: height (m), weight (kg), body circumferences (cm), skinfold thickness (mm), 6-minute walk distance (6MWD) covered (m) and the number of steps taken (a step counter was used) during a 6-minute walk test. Measurements were used to estimate body mass index (BMI) and fat mass (FM), while the 6MWD and the step count were used to prescribe the walking speed (step•min-1) of aerobic training in the EU group. Once-a-week, subjects exercised no later than 24 hrs after the ultrasound treatment. E group has not been recruited yet, thus preliminary results focus on single-group (t0 vs. t1 in either EU or E group) and between-group (EU vs. U of t1-t0 differences) comparisons (Wilcoxon matched-pair test or Mann-Whitney U-test for single-group or between-group comparisons, respectively).
Single group results evidenced, at t1, significant reductions (values in %) of BMI (EU -3.4; U -3.1), weight (EU -3.3; U -3), FM (EU -5.5; U -4.9), and hip (EU -3.6%; U -2.1), umbilicus (EU -2.6; U -1.7), right thigh (EU -4.4; U -3.9), and left thigh (EU -3.8; U -3.3) circumferences, whereas 6MWD improvement was non-significant (EU +5.6; U 0.8) in both groups.
Although between group comparisons revealed no statistical differences among body shape and composition, single group results clearly showed superior effects of the combined intervention. Furthermore, 6MWD - which represents a reliable cardiorespiratory health index - as expected showed a significantly higher improvement in the EU group compared to the U group
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