Itroduction: Involvement in competitive soccer is connected with a high injury rate (Hägglund, 2007). Previous research has suggested that a psychosocial stress (both major and minor stressors) have a great impact on injury risk (Rogers & Landers, 2005; Fawkner et al., 1999).
Aim: The aim of this study was to investigate if individual level and change in psychosocial stress (daily hassle) during a 7 week period could predict injuries among Swedish Premiere League soccer players.
Method: The participants were 56 (38 males and 18 females) Swedish Premiere League soccer players. Participants ranged in age from 16 – 36 years (M = 25, 05, SD = 5, 46). Participants completed the Hassle and Uplift Scale once a week for a 7-week period. During the research period, the physiotherapists for each team were asked to record any injuries occurring during the study period. Latent grpwth curve models were used to examine whether the level and change in psychological stress could predict the frequency of injury over the 7 week period.
Result: The results showed that both high initial levels of daily hassle and negative changes in it were associated with more injuries. Moreover, intra-class correlation showed that 23,4 % of the variance in hassle over the 7 repeated observations could be explained by the within-person variance, whereas the majority of variance (76,6%) could be attributed to between-person variance.
Discussion: The findings highlight the importance of focusing on state variables using prospective designs and appropriate change analysis in order to detect complex and dynamic associations across time in injury prediction research. It is also important to acknowledging and investigating individual differeces in order to understand how psychosocial stressors influence different athletes. Recommendations for players, coaches and physiotherapies are to be observant of the influence from daily hassles in order to be able to help the athlete to decrease injury risk by for example adjusting his/her training load due to psychological status.