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- Is there any effect of symmetry on velocity of the four swimming strokes?Publication . Bartolomeu, Raúl Filipe; Rodrigues, Pedro M.; Santos, Catarina C.; Costa, M.J.; Barbosa, Tiago M.The different characteristics of the four swimming strokes affect the interplay between the four limbs, acting as a constraint to the force produced by each hand and foot. The purpose of this study was to analyze the symmetry of force production with a varying number of limbs in action and see its effect on velocity. Fifteen male swimmers performed four all-out bouts of 25-m swims in the four strokes in full-body stroke and segmental actions. A differential pressure system was used to measure the hands/feet propulsive force and a mechanical velocity meter was used to measure swimming velocity. Symmetry index was calculated based on the force values. All strokes and conditions presented contralateral limb asymmetries (ranging from 6.73% to 28% for the peak force and from 9.3% to 35.7% for the mean force). Backstroke was the most asymmetric stroke, followed-up by butterfly, front crawl, and breaststroke. Kicking conditions elicited the higher asymmetries compared with arm-pull conditions. No significant associations were found between asymmetries and velocity. The absence of such association suggests that, to a certain and unknown extent, swimming may benefit from contralateral limb asymmetry
- Force production and symmetry in water fitness exercises: a gender comparisonPublication . Santos, Catarina C.; Costa, M.J.; Bartolomeu, Raúl Filipe; Barbosa, Tiago M.; Rama, Luís M.The aim of this study was to analyse and compare propulsive forces, relative force production and symmetry between genders during water fitness exercises. Eighteen participants (women, n= 9; age: 20.67± 0.87 years; body mass: 58.18± 4.97 kg; height: 159.19± 5.85 cm; and men, n= 9; age: 22.11± 1.76 years; body mass: 72.93± 7.00 kg; height: 170.83± 5.57 cm) underwent two incremental protocols performing horizontal adduction (HA) and the rocking horse (RHadd) exercises, from 105 to 150 bpm. Propulsive peak force of dominant (PFD) and non-dominant upper-limbs (PFND) was assessed by a differential pressure system. An isokinetic dynamometer was used to collect the dry-land isometric peak strength of the dominant upper-limb. Significant differences between genders were found for most of the music cadences in HA and RHadd. Men were able to produce higher propulsive force values for both upper-limbs during the overall incremental protocol, whereas women reached a higher relative force production. However, no significant differences were found between both genders at the same music cadence. Most actions were asymmetric in women, whereas men showed a symmetric pattern. The cadence of 135 bpm elicits a symmetric motion in both genders while exercising water fitness exercises.
- Comparison of the anthropometrics, kinematics and kinetics in young swimmers of different competitive levelsPublication . Barbosa, Tiago M.; Bartolomeu, Raúl Filipe; Morais, J.E.; Costa, M.J.The biomechanics plays a major role in the performance delivered by young swimmers. However, the literature addresses mostly the differences in the kinematics across young swimmers of different competetive levels, being scarce on the kinetics. The aim was to compare the anthrpmetics, kinematics and kinetics in young swimmers of different competetive levels.
- Avaliação das assimetrias propulsivas em nado livre: ferramenta e diagnóstico para o processo de treinoPublication . Bartolomeu, Raúl Filipe; Rodrigues, Pedro M.; Morais, J.E.; Marinho, D.A.; Costa, M.J.; Barbosa, Tiago M.Atualmente já é possível adquirir no mercado sensores de pressão que se colocam nas mãos e/ou pés de onde se derivam as forças propulsivas com a possibilidade de se detetarem possíveis assimetrias. Foi objetivo do presente estudo ter uma compreensão clara de tais assimetrias num ambiente ecologicamente válido (p.e., nado dinâmico em vez de nado amarrado). máxima em três variantes do nado de crol: completo (C), só com membros superiores (MS) e só com membros inferiores (MI). A medição da força propulsiva em cada uma das condições foi efetuada com recurso a um sistema de monitorização (Aquanex System, DU2V, STR, EUA). Como variáveis definiram-se: o pico de força, a força média, o índice de assimetria (IS) como descrito por Robinson et al (1987), a velocidade média (v) e a frequência gestual (FG).
- The aging influence on cardiorespiratory, metabolic and energy expenditure adaptations in head-out aquatic exercises: differences between young and elderly womenPublication . Bartolomeu, Raúl Filipe; Barbosa, Tiago M.; Morais, J.E.; Lopes, Vitor P.; Bragada, José A.; Costa, M.J.The purpose of this study was to (1) to establish the relationship between acute physiological responses and musical cadence; and (2) compare physiologic responses between young and older women. Eighteen older (mean = 65.06 ± 5.77 years) and 19 young (mean = 22.16 ± 2.63 years) women underwent an intermittent and progressive protocol performing the head-out aquatic exercise "rocking horse. Results showed that older women demonstrated lower mean heart rate (HR), blood lactate concentration (bLa) and oxygen uptake (VO2) at rest. Hierarchical linear modelling showed that variations in the rating of perceived effort (RPE) and individual metabolic equivalent of task (MET) did not differ significantly by age group. However, during exercise, physiological responses of younger women were significantly different than for older women: in mean values, for each increased musical beat per minute (b/min), mean bLa was 0.003 mmol/l, VO2 0.024 ml/kg/min, and energy expenditure (EE) 0.0001 kcal/kg/min higher for younger women. This study shows that increases in musical cadence increased the cardiorespiratory, metabolic and energy expenditure responses. However, these responses during increasing intensity seemed to differ between young and older women, with lower values for the elderly group, when performing head-out aquatic exercises.
- Nonlinear Analysis of the Hand and Foot Force-Time Profiles in the Four Competitive Swimming StrokesPublication . Bartolomeu, Raúl Filipe; Rodrigues, Pedro; Sokołowski, Kamil; Strzała, Marek; Santos, Catarina C.; Costa, M.J.; Barbosa, Tiago M.Human locomotion on water depends on the force produced by the swimmer to propel the body forward. Performance of highly complex motor tasks like swimming can yield minor variations that only nonlinear analysis can be sensitive enough to detect. The purpose of the present study was to examine the nonlinear properties of the hand/feet forces and describe their variations across the four competitive swimming strokes performing segmental and full-body swimming. Swimmers performed all-out bouts of 25 m in the four swimming strokes, swimming the full-body stroke, with the arm-pull only and with the leg kicking only. Hand/foot force and swimming velocity were measured. The Higuchi's fractal dimension (HFD) and sample entropy (SampEn) were used for the nonlinear analysis of force and velocity. Both the arm-pull and leg kicking alone were found to produce similar peak and mean hand/foot forces as swimming the full-body stroke. Hand force was more complex in breaststroke and butterfly stroke; conversely, kicking conditions were more complex in front crawl and backstroke. Moreover, the arm-pull and kicking alone tended to be more complex (higher HFD) but more predictable (lower SampEn) than while swimming the full-body stroke. There was no loss of force production from segmental swimming to the full-body counterpart. In conclusion, the number of segments in action influences the nonlinear behavior of the force produced and, when combining the four limbs, the complexity of the hand/foot force tends to decrease.