This study investigated the influence of the covering swimsuit and the fabric surface properties on the butterfly stroke kinematics. Surface properties were evaluated by wetting measurements of two fabric samples: one for training suits and one for competition suits. The surface of the second one was coated by mechanochemical treatment in order to modify its surface properties. Nine national level swimmers performed a 50-m butterfly at submaximal velocity in three swimsuit conditions: conventional, long, and coated long swimsuits. From video recording, the hip was digitized at the entry and exit of the swimmer's hand in order to calculate the duration, hip displacement, and hip linear velocity during underwater and recovery phases and during stroke. The results for wetting show that competition fabric was more water-repellent than training fabric, but both were isotropic. Moreover, the mechanochemical treatment increased water repellency and anisotropy. The swimming results indicated that, when compared to a conventional swimsuit, wearing a coated long swimsuit increased hip linear velocity during stroke, and particularly during the recovery phase which had a shorter duration. These results suggest that the covering swimsuit should be coupled with the water repellent and anisotropic properties of the fabric surface in order to improve swimming performance.
Isabelle Rogowski, Karine Monteil, Pierre Legreneur and Pierre Lanteri
Alexander Tsouknidas, Nikoalos Michailidis, Savvas Savvakis, Kleovoulos Anagnostidis, Konstantinos-Dionysios Bouzakis and Georgios Kapetanos
This study presents a CT-based finite element model of the lumbar spine taking into account all function-related boundary conditions, such as anisotropy of mechanical properties, ligaments, contact elements, mesh size, etc. Through advanced mesh generation and employment of compound elements, the developed model is capable of assessing the mechanical response of the examined spine segment for complex loading conditions, thus providing valuable insight on stress development within the model and allowing the prediction of critical loading scenarios. The model was validated through a comparison of the calculated force-induced inclination/deformation and a correlation of these data to experimental values. The mechanical response of the examined functional spine segment was evaluated, and the effect of the loading scenario determined for both vertebral bodies as well as the connecting intervertebral disc.
Tzu-Chieh Liao, Joyce H. Keyak and Christopher M. Powers
have impacted our findings. Second, from a mechanical perspective, the biomechanical function of articular cartilage is best understood when the tissue is viewed as a multiphasic medium, with material properties that vary with location (inhomogeneity), direction (anisotropy), loading rate
Alexandra F. DeJong, L. Colby Mangum, Jacob E. Resch and Susan A. Saliba
variability in image quality. It should be noted that even in the context of tightly controlled methods, researchers have found some inconsistency in image quality, supporting the idea that movement presents some image artifact with USI, such as seen with anisotropy. 30 The examiner measuring the muscles was