Performance, control and variability of the forehand badminton smash during different spatio-temporal constraints

The forehand badminton smash is a multisegmented ballistic movement, which requires badminton players to synchronously intercept and rapidly direct the incoming shuttlecock to a desired location. The aims of the study were to 1) identify and compare speed-accuracy trade-off (SATO) relationships utilised by international badminton players when performing the forehand smash, during different spatio-temporal constraints and 2) examine the relationship between intra-individual movement variability and performance outcomes during different constraints. Fifty-two (29 male; 23 female) elite international badminton players from the BWF Glasgow world championships (2017) and one elite international men’s singles player from the BWF All England open Championships (2016) participated in the study. Data were collected on practice courts using an 18 camera Vicon 3D motion capture system (400 Hz; OMG Plc, Oxford, UK). Findings indicate that when the target size was reduced, those players adopting a high inverse SATO relationship (reduction in shuttlecock speed, improvement in spatial accuracy) were able to achieve the highest levels of spatial accuracy (shuttlecock landing location). However, similarly high levels of spatial accuracy were also shown in the cluster of players who were able to consistently maintain close to maximum shuttlecock speed (low-inverse SATO). When using badminton tubes as a task constrained target, female athletes were able to smash at a significantly faster mean shuttlecock speed and with a smaller vertical racket angle during the forward swing phase in comparison to when a flat target (CC) was used. Findings show that players who were able to reduce racket head speed when target size was reduced, had lower variability in terms of impact location on the racket face. A case study of one international badminton player showed that joint angle variability in both proximal and distal segments was greater during the preparatory phase compared to both the backswing and forward swing phases, when comparing the spatial accuracy condition to the maximal speed condition. Shuttlecock speed and impact location on the racket face had a lower variability in the spatial accuracy condition. This study’s adaptation of Fitts’ Law (model) could serve useful for badminton coaches and sports scientists, in identifying performance baselines for SATO amongst international badminton players.