ABSTRACT
Objective To explore the relationship of neck pain,neck disability index(NDI),and surface eleetromyography(sEMG)in subjects with work-related neck and shoulder musculoskeletal disorders.Methods Fifry-five patients with neck and shoulder pain participated in this study.VAS and NDl were used to evaluate the degree of pain and disability of the patients.The signals of maximum voluntary contraction(MVC)and typing status were recorded using the sEMG recording techniques.The amplitude of typing status was used to normalize the amplitude of MVC of each side of both neck and shoulders and the amplitude probability distribution function(APDF)of 50%MVC was calculated.Then.the relationship of VAS,NDI and the APDF values of each side of both neck and shouIders were compared.Results VAS was correlated to the NDI(P<0.01)and the APDF of 50%MVC and the later had significant differences according to different degrees of pain[mild to moderate pain(VAS<7)versus severe pain(VAS ≥7)];NDI had no relationship with the APDF of 50%MVC and the later had no significant differences according to different degrees of NDI[mild to moderate(NDI<25)versus severe pain(NDI≥25)].Conclusion VAS was correlated to the APDF of 50%MVC and the later had significant differences according to different degrees of pain:but NDI had no relationship with the APDF of 50%MVC.