TY - JOUR
T1 - Why is the humeral retroversion of throwing athletes greater in dominant shoulders than in nondominant shoulders?
AU - Yamamoto, Nobuyuki
AU - Itoi, Eiji
AU - Minagawa, Hiroshi
AU - Urayama, Masakazu
AU - Saito, Hidetomo
AU - Seki, Nobutoshi
AU - Iwase, Takenobu
AU - Kashiwaguchi, Shinji
AU - Matsuura, Tetsuya
PY - 2006/9
Y1 - 2006/9
N2 - A rotation angle of the proximal humerus relative to the elbow (bicipital-forearm angle) was measured by use of ultrasonography to determine the relationship between humeral retroversion and growth in dominant and nondominant shoulders of 66 elementary and junior high school baseball players. The subjects were aged 12 years on average. The bicipital-forearm angle was significantly smaller in dominant shoulders than in nondominant shoulders. This indicated that the retroversion angle was greater in dominant shoulders than in nondominant shoulders. Furthermore, there was a moderately positive correlation between age and the bicipital-forearm angle in both dominant and nondominant shoulders. From these data, we conclude that the humeral retroversion angle decreases with age, and the decrease is much smaller in dominant shoulders. We assume that the repetitive throwing motion does not increase the retroversion of the humeral head but rather restricts the physiologic derotation process of the humeral head during growth.
AB - A rotation angle of the proximal humerus relative to the elbow (bicipital-forearm angle) was measured by use of ultrasonography to determine the relationship between humeral retroversion and growth in dominant and nondominant shoulders of 66 elementary and junior high school baseball players. The subjects were aged 12 years on average. The bicipital-forearm angle was significantly smaller in dominant shoulders than in nondominant shoulders. This indicated that the retroversion angle was greater in dominant shoulders than in nondominant shoulders. Furthermore, there was a moderately positive correlation between age and the bicipital-forearm angle in both dominant and nondominant shoulders. From these data, we conclude that the humeral retroversion angle decreases with age, and the decrease is much smaller in dominant shoulders. We assume that the repetitive throwing motion does not increase the retroversion of the humeral head but rather restricts the physiologic derotation process of the humeral head during growth.
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U2 - 10.1016/j.jse.2005.06.009
DO - 10.1016/j.jse.2005.06.009
M3 - Article
C2 - 16979051
AN - SCOPUS:33748426174
VL - 15
SP - 571
EP - 575
JO - Journal of Shoulder and Elbow Surgery
JF - Journal of Shoulder and Elbow Surgery
SN - 1058-2746
IS - 5
ER -