Sequential focus of attention instructions influenced motor performance of volleyball setting despite direction of focus but dependent on motor expertise of the player

Previous studies have shown the advantage of external over internal focus of attention (FOA) for motor learning and performance. However, such a FOA effect is inconsistent when factors such as motor expertise, individual preference, and performance measurement are considered. For complex motor skills like volleyball setting, sequential FOA instructions (S-FOA) are often given to facilitate skill acquisition and performance, but it remains unknown whether internal and external FOA instructions would impact motor performance of skilled and novice players differently. Thirty-two novice (n =16) and skilled (n = 1 6) female volleyball players were asked to perform a simulated volleyball setting task without (control) and with S-FOA (internal or external). Both movement outcomes and inter-joint coordination of flexion and extension were analysed using linear models and time-series analysis. The results supported previous literature on motor expertise showing that skilled players outperformed novice players with superior movement outcomes due to their ability to maintain an intermediate coordination pattern and functional variability of inter-joint coordination prior to ball contact. Despite direction of focus, S-FOA degraded the mean setting accuracy of skilled players without impacting their mean inter-joint coordination pattern and it also failed to influence the performance of novice players. Although S-FOA failed to impact the mean inter-joint coordination patterns of all participants, they allowed individuals to develop idiosyncratic coordination patterns for setting. S-FOA significantly reduced the variability of inter-joint coordination before and after ball contact for all players, however, it was considered detrimental for skilled players but beneficial for novice players.