Objective: To compare the acromiohumeral distance (AHD) and the change of this distance during abduction between the dominant and nondominant shoulders of female overhead athletes and to compare AHD between elite and recreational female athletes.
Design: : Case-control study.
Setting: Laboratory, institutional.
Independent variables: "Side" (dominant and nondominant), "group" (elite and recreational athletes), and "degree of abduction" (0, 45, and 60 degrees).
Participants: Sixty-two female overhead athletes participated in this study: 29 elite handball players and 33 recreational overhead athletes of different sports disciplines (volleyball, water polo, squash, and badminton).
Main outcome measures: Acromiohumeral distance was measured at 3 positions of abduction using ultrasound: at 0, 45, and 60 degrees of abduction.
Results: Acromiohumeral distance measurements showed good test-retest reliability (intraclass correlation coefficients between 0.88 and 0.92). In all overhead athletes, the AHD was significantly larger on the dominant side compared with the nondominant side, at all positions of abduction (mean difference = 0.94 ± 0.18 mm). Significant reduction of the AHD during abduction occurred relative to the initial size at 0 degree of abduction, at both sides. When comparing elite and recreational athletes, the AHD was significantly larger in elite athletes (mean difference = 0.92 ± 0.47 mm). Moreover, significantly less reduction occurred during the first degrees of abduction (0-45 degrees) in elite athletes (9.37% ± 2.17% reduction) compared with the recreational athletes (17.68% ± 2.03% reduction).
Conclusions: The AHD is larger on the dominant side compared with the nondominant side and in elite female athletes compared with recreational female athletes. Moreover, less reduction of the AHD occurs in the elite athlete group during the first 45 degrees of abduction.