Validity and reliability of the chronic composite XA, an upper limb motor assessment using Active Range of Motion in patients with chronic stroke.

Background: Upper limb (UL) spastic paresis has been classically evaluated with assessments of passive movements with limited functional validity. The aim of this study was to assess whether a composite measure of active range of motion (AROM, or X<inf>A</inf>) is valid and reliable in chronic post-stroke spastic paresis.
Aim: The primary objective was to investigate the validity and reliability of a composite score, comprising multiple X<inf>A</inf> measurements, to assess UL spastic paresis in patients in chronic stages post-stroke. In addition to this, an exploratory analysis was conducted to identify which muscles should be optimally included in this composite score.
Design: A psychometric proprieties study.
Setting: Physical and Rehabilitation Medicine Department.
Population: twenty-eight chronic post-stroke participants with spastic paresis.
Methods: Composite UL X<inf>A</inf> measurement in twenty-eight chronic post-stroke participants (age=59±11 years; delay post-stroke=29±37 months) with spastic paresis was repeated twice about 40 days apart in a standardized body position. Concurrent and construct validity was evaluated exploring correlation with the Fugl-Meyer Assessment Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), and grip strength (JAMAR™). Reliability was assessed by calculating intraclass correlation coefficients (ICC). Regarding the exploratory analysis, a linear regression analysis was performed to examine the value of including various muscles.
Results: Composite X<inf>A</inf> against the resistance of elbow, wrist and finger flexors showed strong correlation with FMA-UE and ARAT (r=0.88; P<0.001 and r=0.82; P<0.001 respectively) and a weak association with grip strength (r=0.43; P=0.03). Test-retest reliability was excellent (ICC=0.92). However, the most effective regression model also included X<inf>A</inf> against the resistance of shoulder adductors as well as forearm pronator (adjusted R ² =0.85; AIC=170).
Conclusions: The present study provided satisfactory psychometric data for the upper limb composite active movement (CX<inf>A</inf>), derived from the Five Step Assessment. For overall measurement of UL mobility after stroke, we strongly recommend including shoulder and forearm muscles to the score.
Clinical Rehabilitation Impact: Composite X<inf>A</inf> is a valid and reliable measure of upper limb motor function in chronic post-stroke patients and could be used in clinical practice and research.