Measurement of anterior/posterior shoulder tightness, humeral external/internal rotation range of motion (ROM), scapular upward rotation/tipping ROM, and functional limitations were made in 46 patients with unilateral stiff shoulders (SSs) using a clinical measurement (shoulder tightness), a three-dimensional electromagnetic tracking device (shoulder ROM), and self-reports of function. Patients with SSs in their dominant shoulder demonstrated statistically greater posterior shoulder tightness compared to nondominant shoulder. Control dominant shoulders demonstrated decreased internal ROM as compared with control nondominant shoulders (p=0.021). In SSs, significant relationships were found between humeral internal rotation ROM and posterior shoulder tightness (R=0.49, p<0.0005), humeral external rotation ROM and anterior shoulder tightness (R=0.59, p=0.0002), scapular tipping and anterior shoulder tightness (R=0.57, p=0.004). Specifically, in patients with dominant SSs, posterior shoulder tightness and functional limitation were related (R=0.56, p=0.002). In patients with dominant involved shoulders, emphasise on posterior tightness stretch may improve functional ability directly. In addition to stretching program in patients with SSs, internal rotation ROM of control dominant shoulder is also important to consider in the rehabilitation of patients with SSs.