C5–C6 and thoracic spine mobilization with postural correction exercise compared with conventional therapy in patients with adhesive capsulitis: a two-group, parallel-arm, single-blinded, randomized clinical trial—study protocol

Adhesive capsulitis (AC) often resolves independently but can persist for years and may not fully improve. The most effective treatments for AC are not well established. Although the shoulder girdle muscles are primarily controlled by the cervical nerve roots, particularly C5 and C6, research linking these roots to the pathogenesis of AC is currently lacking. While existing studies suggest a connection between thoracic mobility, posture, and shoulder mobility, the potential benefits of mobilizing the C5–C6 region and thoracic spine, in conjunction with postural correction exercises for treating AC, have yet to be explored. This study protocol will be to assess the effectiveness of C5–C6 and thoracic spine mobilization combined with postural correction exercises, compared to conventional therapy, in alleviating pain, improving range of motion (ROM), and reducing disability in patients with AC. This study will be a two-group, randomized controlled trial with assessors blinded to group assignments. A total of 66 adults with AC will be randomly allocated into two groups: the experimental group (n = 33), which will undergo C5–C6 and thoracic spine mobilization along with postural correction exercises, and the control group (n = 33), which will receive conventional therapy, for 3 weeks. The primary outcomes will include shoulder pain, shoulder joint range of motion, and the Disability Index, all of which will be assessed at baseline, immediately post-intervention, and 3 months after randomization. An intention-to-treat approach will be employed for the analysis. Additionally, a sensitivity analysis will be performed using a per-protocol approach to examine the potential impact of incomplete adherence and participant dropout. Linear mixed models will be applied to investigate the main effects and interactions of the group and time on the study outcomes, adjusting for covariates such as age, sex, duration of condition, and presence of comorbidities. Multiple imputation methods will be utilized to address any missing data. This study's findings will help assess the effectiveness of spinal manual therapy combined with postural correction exercises in patients with AC compared to traditional physiotherapy. Additionally, the prognostic value of AC may be improved based on these results. We will track the treatment outcomes through immediate, short-term, and mid-term follow-ups. ClinicalTrials.gov NCT06449261. This study protocol is Version 1.0, dated 07 June 2024.