Correlation between Trunk Posture and Neck Reposition Sense among Subjects with Forward Head Neck Postures

OBJECTIVE To assess the correlation of abnormal trunk postures and reposition sense of subjects with forward head neck posture (FHP). METHODS In all, postures of 41 subjects were evaluated and the FHP and trunk posture including shoulder, scapular level, pelvic side, and anterior tilting degrees were analyzed. We used the head repositioning accuracy (HRA) test to evaluate neck position senses of neck flexion, neck extension, neck right and left side flexion, and neck right and left rotation and calculated the root mean square error in trials for each subject. Spearman's rank correlation coefficients and regression analysis were used to assess the degree of correlation between the trunk posture and HRA value, and a significance level of α = 0.05 was considered. RESULTS There were significant correlations between the HRA value of right side neck flexion and pelvic side tilt angle (p < 0.05). If pelvic side tilting angle increases by 1 degree, right side neck flexion increased by 0.76 degrees (p = 0.026). However, there were no significant correlations between other neck motions and trunk postures. CONCLUSION Verifying pelvic postures should be prioritized when movement is limited due to the vitiation of the proprioceptive sense of neck caused by FHP.