# Determining the Level to Affect of Physical Findings and Outcome Measures on Functional Status in Partial-Thickness Rotator Cuff Tears Using a Multiple Linear Regression Model

## TL;DR

This study identifies which physical and outcome measures most affect shoulder function in patients with partial rotator cuff tears.

## Contribution

The paper introduces a multiple regression model to quantify the impact of specific physical and outcome measures on functional status in partial-thickness rotator cuff tear patients.

## Key findings

- Shoulder flexion and external rotation range of motion and disability level significantly predict functional status.
- Pain levels and health-related quality of life did not show a significant predictive effect on functionality.
- The regression model explained 76% of the variance in functional status among patients.

## Abstract

Background and Objectives: It is crucial to determine physical findings and outcome measures that affect functional status of the patients, and the impact levels of these parameters on patients. Therefore, the aim of this study was to investigate the determinant and predictive effect of pain levels, shoulder range of motion (ROM) values, disability and health-related quality of life factors on functional status in individuals with partial-thickness rotator cuff tears (PRCT). Materials and Methods: Firstly, the functional status of 45 patients (mean age: 50.78 ± 5.28 years; 29 female) with PRCT, then activity and night pain levels with Numeric Pain Rating Scale, active flexion, abduction and external rotation of the shoulder ROM values with goniometer, disability level with Quick Disabilities of Arm, Shoulder & Hand Questionnaire, and health-related quality of life levels with Short Form-12 were evaluated and recorded. Results: It was detected that all determinants whose effect on functionality was evaluated with a multiple regression model explained 76% of the variance, and this effect level was statistically significant (R square = 0.760, adjusted R square = 0.707, F = 14.272, p < 0.001). Detailed evaluation showed that flexion and external rotation ROM values (respectively; β = 0.54, p < 0.001; β = 0.38, p = 0.001) and disability level (β = 0.44, p < 0.001) had statistically significant determinant effects on functional status. No statistically significant results which could be correlated with functional status were found for activity and night pain, abduction ROM value, and health-related quality of life domains (p > 0.05). Conclusions: Shoulder flexion and external rotation ROMs and disability level were found to have a predictive effect on the functional status in individuals with PRCT. It is noteworthy that more subjective and patient-reported findings and outcome measures such as pain and health-related quality of life had no predictive effect on functionality. By determining the level of these effects, results were reached that can shed light on the literature by guiding the development of reliable assessment algorithms.