Intraindividual Movement Variability Within the 5 m Water Polo Shot

Abstract

The purpose of this study was to explore movement variability of throwing arm and ball release parameters during the water polo shot and to compare variability between successful (hit) and unsuccessful (miss) outcomes. Seven injury free, subelite, females completed 10 trials of the 5 m water polo penalty shot. Intraindividual coefficient of variation percentage (CV%) values were calculated for elbow and wrist angular displacement, wrist linear velocity and ball release parameters (height, angle and velocity). Coordination variability (elbow/wrist angular displacement) was calculated as the CV% of the mean cross-correlation coefficient. Elbow and wrist displacement variability decreased to 80% of throwing time then increased toward release. Wrist linear velocity variability reduced toward release. Individual CV% values ranged between 1.6% and 23.5% (all trials), 0.4% and 20.6% (hit), and 0.4% and 27.1% (miss). Ball release height and velocity variability were low (< 12%; all trials) whereas release angle variability was high (>27%; all trials). Cross-correlation results were inconclusive. Roles of the elbow and wrist in production of stable ball release height and velocity and control of the highly variable release angle in the water polo shot are discussed and suggested for further study. Optimal levels of variability warrant future investigation.

Shoulder injury in water polo: A systematic review of incidence and intrinsic risk factors

“…5,37 Superior throwing performance has been shown to be characterised by decreased movement variability at critical points within the penalty shot. 54 Although shooting proficiency is adversely affected by increased exertion, height out of the water, elbow angle and position at release, ball speed and accuracy were all maintained under fatigue. 55 Reduction in movement variability at the elbow before ball release suggests that a threshold may exist to improve throwing accuracy and potentially reduce injury risk.…”

“…To improve athletes throwing proficiency, the literature demonstrates value in coaches focussing on increasing athletes overall fitness 55 as well as practicing throwing skill under pre-fatigue conditions. 54 Dynamic shoulder stability is derived from muscular as well as neuromuscular control. Recent research has shown that the quality of an individual's proprioception is associated with the level at which they perform in their sport.…”

The kinematic differences between skill levels in the squash forehand drive, volley and drop strokes

“…Although highly dynamic movements can produce errors in marker tracking due to the movement of the skin and muscle (Gordon & Dapena, 2006), triad clusters of markers have been shown to produce more accurate results (Elliott et al, 2007) and reduce the effect of soft tissue artefacts (Cappozzo et al, 1995). The same upper-limb model has been used previously to evaluate shoulder and humerus rotations in volleyball (Seminati et al, 2015), overarm throwing technique (Taylor et al, 2015), water polo shot technique (Taylor et al, 2014) and hand-cyclist kinematics (Abel et al, 2010). Validation and additional information on the model can be found in Cutti et al (2005) and Murray (1999).…”

Field-based upper-body motor variability as determinant of stroke performance in the main tennis strokes

“…The use of the CV to assess motor coordination variability is common. 1,9,28,33 The average of the angular velocity peaks was also used as a descriptive parameter for the data. Prior to the calculation of means and CVs, outliers were removed with a conservative filter based on the median and the Median Absolute Deviation (MAD).…”