The impact of limb deficiency impairment on Para swimming performance

ABSTRACT

Swimmers with limb deficiency are a core population within Para Swimming, accordingly this study examined the contribution of limb segments to race performance in these swimmers. Data were obtained for 174 male Para swimmers with limb deficiency. Ensemble partial least squares regression showed accurate predictions when using relative limb segment lengths to estimate Para swimmers’ personal best race performances. The contribution of limb segments to performance in swim events was estimated using these regression models. The analysis found swim stroke and event distance to influence the contributions of limb segments to performance. For freestyle swim events, these changes were primarily due to the increased importance of the hand, and decreased importance of the foot and shank, as the distance of the event increased. When comparing swim strokes, higher importance of the thigh and shank in the 100 m breaststroke compared with other swim strokes confirms the separate SB class. Varied contributions of the hand, upper arm and foot suggest that freestyle could also be separated from backstroke and butterfly events to promote fairer classification. This study shows that swim stroke and event distance influence the activity limitation of Para swimmers with limb deficiency suggesting classification should account for these factors.     

Single versus Multiple Sets for Strength: A Meta-Analysis to Address the Controversy

We assessed the factor structure of a revised version of the Exercise Imagery Inventory (EII; Giacobbi, Hausenblas, &; Penfield, 2005), second-order interrelationships for cognitive and motivational forms of mental imagery, and associations with exercise behavior and barriers self-efficacy. A convenience sample of 358 (M age = 20.55 years, SD = 3.88) college students completed the EII-revised (EII-R), a measure of barriers self-efficacy and the Leisure-Time Exercise Questionnaire. The EII-R demonstrated reliability and factorial validity with good model fit statistics. We observed second-order relationships among scale scores and discriminant validity evidence that distinguished cognitive (e.g., exercise technique, exercise routines) and motivational (e.g., appearance/health, exercise self-efficacy, exercise feelings) factors. The second-order imagery factors were significantly and moderately associated with barriers self-efficacy and exercise behavior.     

The influence of dive direction on the movement characteristics for elite football goalkeepers

This study biomechanically quantified the movement patterns for six elite goalkeepers making diving saves to their preferred and non-preferred side at three different dive heights. Synchronised three-dimensional kinematic and kinetic biomechanical data analysis found diving direction to significantly (P < 0.05) influence the movement patterns of the diving save. The non-preferred side displayed greater lateral rotation of the pelvis and thorax at the initiation event. These over-rotational differences were reduced during the time on plate phase with the thorax displaying no significant difference at take-off; although a difference still remained for the pelvis. These over rotations were subsequently linked to greater peak knee joint moments, lower peak ankle joint moments, less hip extension at take-off, and for the centre of mass (COM) to travel slower and less directly to the ball, as measured by the net projection angle at take-off. These results indicate that joint movements in the transverse plane at or before the initiation event for the dive for the pelvis and thorax are the causation for subsequent asymmetries. These observed differences indicate that there is an advantage in having prior knowledge of limb preference in an opposing goalkeeper.     

中国竞技乒乓球后备人才多维度可持续发展培养模式的探索与研究

中国竞技乒乓球后备人才的可持续发展是中国竞技乒乓球运动保持长盛不衰的根本保证。建国以来“举国体制”的培养方式造就了大量的世界冠军,使中国的乒乓球事业蓬勃发展,但随着中国改革开放的深入和对人才需求的不断变化,原有的培养模式已不能满足竞技乒乓球运动可持续发展的需要。“发展、协调、持续”是和谐发展的三个维度,本文旨在分析多维度和谐发展对于乒乓球后备人才培养的重要性,探索和研究构建中国竞技乒乓球后备人才可持续发展培养模式的可行性及其重要意义。