# Validity of the short version of the Upper Limb Functional Index with 10 items in Brazilian patients with chronic musculoskeletal dysfunction in the upper limb

## TL;DR

This study confirms that a 10-item version of the Upper Limb Functional Index is a valid and reliable tool for assessing upper limb function in Brazilian patients with chronic musculoskeletal issues.

## Contribution

The study validates the structural and criterion validity of a shortened 10-item version of the Upper Limb Functional Index for Brazilian patients.

## Key findings

- The 10-item Upper Limb Functional Index showed good fit indices (CFI=0.970, TLI=0.962, RMSEA=0.054, SRMR=0.078).
- There was an excellent correlation (rho=0.900) between the 10-item and 25-item versions of the index.
- The 10-item version is recommended for assessing upper limb function in Brazilian patients with chronic musculoskeletal dysfunction.

## Abstract

The aim of this study was to validate the structural and criterion validity of the short version of the Upper Limb Functional Index with 10 items in Brazilian patients with musculoskeletal dysfunction in the upper limb.

The structure of the Upper Limb Functional Index with 10 items and with one domain was tested using confirmatory factor analysis with model fit evaluated using comparative fit index, Tucker-Lewis index, root mean square error of approximation, standardized root mean square residual, and chi-square/degree of freedom. Criterion validity was assessed using Spearman's correlation coefficient (rho) to correlate the Brazilian versions of Upper Limb Functional Index with 25 items and Upper Limb Functional Index with 10 items.

We included 150 patients, mostly women, with an average age of 52.21±12.09 years, diagnosed with chronic musculoskeletal dysfunction in the upper limbs. The Upper Limb Functional Indexwith 10 items showed sufficient fit indices (CFI=0.970, TLI=0.962, RMSEA=0.054, SRMR=0.078, chi-square/DF=1.43). Criterion validity showed an excellent correlation between Upper Limb Functional Indexwith 25 items and Upper Limb Functional Index with 10 items, with rho=0.900 (p<0.001).

The Upper Limb Functional Index with 10 items demonstrated sufficient unidimensional structure and high correlation with the original version. We recommend the use of Upper Limb Functional Index with 10 items for assessing upper limb functioning in Brazilian patients with chronic musculoskeletal dysfunction.