Intra- and inter-rater reliability of goniometric head posture measurement in patients with neck pain and hamstring tightness

Neck pain (NP) is a common disabling condition, often associated with forward head posture (FHP) and hamstring tightness. There is limitation in evidence regarding the intrarater and interrater reliability of FHP evaluation through the universal goniometer (UG) in NP with hamstring tightness. This study aimed to evaluate the intrarater and interrater reliability of the goniometric method for measuring head posture in patients having NP and hamstring tightness. This intrarater and inter-rater reliability (between and within-day, respectively) study was conducted on 61 participants having the NP with hamstring tightness at Sindh Institute of Physical Medicine and Rehabilitation, Karachi, Pakistan. Two independent examiners, 1 and 2, measured the FHP using universal goniometer (UG). The measurements were performed by both examiners on day 1. Examiner 1 repeated the measurements after an interval of 2 days. Both examiners were blinded to each other’s readings. Intrarater and interrater reliability were assessed using the Intraclass Correlation Coefficient (ICC) and the Bland-Altman plot. There was high intrarater reliability with an ICC of 0.96 (95% CI: 0.92, 0.97; SEM: 0.09 and MCD: 0.24), and interrater reliability with an ICC of 0.97 (95% CI: 0.94–0.98; SEM: 0.10 and MCD: 0.27) of the UG in patients with NP with hamstring tightness. Moreover, both the intrarater and interrater agreements for measuring the FHP using a UG fell to the acceptable limits of agreements on 95% CI. The upper and lower limits of agreement values are 1.06 to -1.58 degrees and 1.05 to -1.75 degrees for the intrarater and interrater reliability, respectively. From the findings of the study, it is concluded that the UG provides excellent intrarater and interrater reliability to measure FHP among patients having NP with hamstring tightness.