Relationship between kinematic variability and performance in basketball free-throw

The role of ball path curvature in basketball shooting accuracy

During the shooting motion of a basketball, the path of the ball from the beginning of the lift to release follows an S-shaped trajectory. This study is the first to investigate how two distinctive features of the S-shaped ball path, the maximum curvature, κmax, and terminal curvature, σ, are associated with longitudinal accuracy. The sagittal plane ball path and curvature were found using Bezier curves for 31 professional male basketball athletes. Terminal release curvature had a very strong positive correlation to intra-individual release velocity standard deviation (r = 0.73, p < 0.001) indicating that shooters with straighter terminal ball paths had better longitudinal shooting accuracy. It was also observed that κmax coincided with the transition to the forward shooting motion and that players with higher κmax tend to have a clear two-part shooting style rather than a single fluid motion. A comparison between groups of good and poor shooters identified a mean difference in κmax of 7.9 m-1 (p < 0.001, 95% CI: 11.8-4.0 m-1) suggesting that good shooters typically have a higher κmax than poor shooters.

Applying augmented feedback in basketball training facilitates improvements in jumping performance

Augmented feedback, which is feedback about movement characteristics provided by an external source, can facilitate performance improvements. Results from recent studies, in which information about the jumping height were presented, indicated increased jumping performance due to augmented feedback. In the present study we aimed to utilize augmented feedback about the jumping height in regular basketball training. Therefore, augmented feedback was implemented and part of the training regime, and information about the jumping height was displayed while subjects performed catch and shoot exercises with the basketball. 18 subjects (9 with augmented feedback, 9 without augmented feedback) practiced for 3 weeks (9 training sessions). The subjects receiving augmented feedback, but not subjects in the control group, displayed increased jumping heights of countermovement-jumps and drop-jumps after the training. The ground contact times of countermovement-jumps and drop-jumps were not significantly changed after training. The number of successful hits, indicating ball performance, did also not change after training. Thus augmented feedback had no detrimental effect on sport-specific performance. The unchanged ground contact times of drop-jumps in combination with increased jumping heights indicate increased efficiency of stretch shortening cycle contractions. According to the positive effect of augmented feedback on jumping performance and the simplicity with which it was integrated into the training regime we recommend this method for regular basketball training.HighlightsAugmented feedback about the jumping height in basketball training facilitated jumping height of countermovement-jumps and drop-jumps.The ground contact times were not altered, suggesting increased efficiency of the stretch-shortening cycle during jumping.According to the positive effect and its simple implementation augmented feedback is recommended for regular basketball training.

The role of ball backspin alignment and variability in basketball shooting accuracy

Interaction between the shooting hand and ball at the moment a basketball is released generates a three-dimensional backspin of the ball. This study is the first to investigate how characteristics of the backspin alignment and variability contribute to lateral shooting accuracy. Spin axis (SA) direction and backspin magnitude were measured on 25 shot attempts for 26 collegiate basketball players (male: n = 16, female: n = 10). The mean SA alignment, as viewed from the shooting hand side, was found to be tipped down and towards the target (p < 0.001). Standard deviations (SD) in the SA alignment were strong predictors of lateral accuracy (vertical SD: r = 0.80, p < 0.001, forward-backward SD: r = 0.51, p = 0.01), with variation in the vertical alignment being the best predictor. No significant correlation between mean SA misalignment and lateral accuracy was observed. However, intra-individual relationships between SA misalignment and lateral error revealed that individuals tended to have 0.17 degrees more misalignment for each cm of lateral error (p < 0.001, 95% CI: 0.24-0.09). These indicate that while an individual's mean alignment may not predict lateral accuracy, improving one's SA alignment and reducing alignment variability may increase lateral accuracy.