SPECIFICITY OF JUMPING, ACCELERATION AND QUICK CHANGE-OF-DIRECTION MOTOR ABILITIES IN SOCCER PLAYERS

The purpose of this study was to determine the underlying structure of the stretch-shortening cycle (SSC) jumping, acceleration and change-of-direction (COD) abilities in soccer players using principal component factor analysis (PCA). Based on the results of recent studies on male college athletes, we hypothesized that slow SSC jumping, acceleration and COD represent independent motor abilities in soccer players. Forty two soccer players (23.2 +/- 2.36 yr) performed three tests for each group of rapid lower-body movements: a) three vertical slow SSC jumping tests. squat jump (SJ), countermovement jump (CMJ) and arm swing countermovement jump (CMJAS), b) three acceleration tests. 5, 10 and 15 meter sprint times (ACC5, ACC10 and ACC15), and c) three COD tests. modified agility test free (MATF), the 505 agility test (505) and 20 yard agility test (Y20). PCA was applied to establish the relationships among the factors (i.e. motor abilities) underlying the included manifest variables (i.e. performance tests). This procedure reduced all variables to a smaller number of independent latent dimensions. The results indicated three separate factors that may correspond to slow SSC jumping, acceleration and COD abilities. The magnitude of the correlation coefficients among the three motor abilities extracted was r<.56. Therefore, it is suggested that slow SSC jumping, acceleration and COD abilities represent independent motor abilities and consequently these should be trained and evaluated separately to assess soccer players' physical profiles.