TY - JOUR
T1 - The effect of scapular protraction on isometric shoulder rotation strength in normal subjects
AU - Smith, Jay
AU - Dietrich, Christopher T.
AU - Kotajarvi, Brian R.
AU - Kaufman, Kenton R.
PY - 2006/5
Y1 - 2006/5
N2 - To measure the effect of scapular protraction on isometric shoulder rotation strength, 20 normal subjects completed 2 maximal isometric internal and external rotation contractions in 2 scapular positions (scapula neutral [SN] and scapula protracted [SP]) from 3 arm positions (90° internal rotation [IR], 45° internal rotation [MR], and 90° external rotation [ER]). Scapular protraction reduced shoulder rotation strength in 5 of 6 test positions (P < .0004), with significant interactions between scapular position and arm position (P < .001) and between scapular position and contraction type (P < .0001). Protraction significantly reduced IR strength by 13% to 24% relative to SN. The effect of SP on ER strength was more position-dependent, increasing strength by 6% in the IR position and decreasing it by 7% in the MR position and 20% in the ER position. In conclusion, acute changes in scapular position affect shoulder isometric IR and ER strength. The potential adverse effects of scapular protraction on shoulder rotation strength should be considered during the evaluation and treatment of shoulder pain.
AB - To measure the effect of scapular protraction on isometric shoulder rotation strength, 20 normal subjects completed 2 maximal isometric internal and external rotation contractions in 2 scapular positions (scapula neutral [SN] and scapula protracted [SP]) from 3 arm positions (90° internal rotation [IR], 45° internal rotation [MR], and 90° external rotation [ER]). Scapular protraction reduced shoulder rotation strength in 5 of 6 test positions (P < .0004), with significant interactions between scapular position and arm position (P < .001) and between scapular position and contraction type (P < .0001). Protraction significantly reduced IR strength by 13% to 24% relative to SN. The effect of SP on ER strength was more position-dependent, increasing strength by 6% in the IR position and decreasing it by 7% in the MR position and 20% in the ER position. In conclusion, acute changes in scapular position affect shoulder isometric IR and ER strength. The potential adverse effects of scapular protraction on shoulder rotation strength should be considered during the evaluation and treatment of shoulder pain.
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U2 - 10.1016/j.jse.2005.08.023
DO - 10.1016/j.jse.2005.08.023
M3 - Article
C2 - 16679235
AN - SCOPUS:33646193187
SN - 1058-2746
VL - 15
SP - 339
EP - 343
JO - Journal of Shoulder and Elbow Surgery
JF - Journal of Shoulder and Elbow Surgery
IS - 3
ER -