The reliability and concurrent validity of goniometric and visual estimation in participants with unilateral shoulder pain

Introduction

The Constant-Murley Score (CMS) uses universal goniometry (UG), and the Shoulder Functional Reach Score (SFRS) uses visual estimation (VE). The CMS has validity challenges, and the SFRS has been critiqued for using VE. This study sought to determine the reliability and concurrent validity of VE when compared to the UG for shoulder flexion and abduction. Differences between symptomatic and asymptomatic shoulder and expert and novice raters were also explored.

Methods

Participants were included if they were at least 18 years old with unilateral, symptomatic shoulder pain, with no post-surgical contraindications. All conditions were randomized, and raters were blinded.

Results

The intertester reliability for UG had Intraclass Correlation Coefficient (ICC) values of 0.76–0.91 at visit one. VE had ICC values that ranged from 0.87 to 0.92 at visit one. VE test-retest reliability had ICC values from 0.81 to 0.94. At visit one, concurrent validity was demonstrated by rho values from 0.84 to 0.89. There were statistically significant differences between the shoulders (P ≤ 0.0448), and there were no differences between the raters (P ≥ 0.0960).

Discussion

UG and VE of active shoulder flexion and abduction are reliable and concurrently valid. Additionally, there were differences between symptomatic and asymptomatic shoulders, and there were no differences between novice and expert raters.

Conclusion

The SFRS may be reliable and valid for measuring shoulder motion using VE within and between treatment sessions. Future research should examine this in larger, more diverse participant populations.