The purpose of this study was to evaluate a isometric shoulder muscle strength of normal men and women in three age groups. 128 healthy Korean adults between the ages of 20 to 79 were studied(men were 59 and women 67). Isometric shoulder strength was measured by Nicholas hand-held dynamometer for flexors, extensors, abductors, adductors, external rotators, and internal rotators of shoulders. Testing was performed with the subject supine according to the modified Bohannon's method. There was a tendency which was dominant side weakness in external rotators compared with nondominant side in more than 40 years old of both men and women. Analysis with paired t-test showed that measured shoulder strength for flexors, extensors, and abductors in dominant side had significantly more(p<0.05) strength(kg) than nondominant side in Korean adults.

In conclusion, this hand-held dynamometer is a convenient and beneficial instrument for the evaluation of shoulder strength and it could be used as a screening test for the diseases causing muscle weakness.