The influence of upper extremity improvement on daily function in individuals with chronic stroke following task-oriented interventions: a structural equation modeling approach

Stroke survivors often experience persistent upper extremity (UE) motor impairments, which significantly hinder their ability to perform daily functions. While various components of UE motor abilities—such as impairment severity, muscle strength, and motor function—have been linked to daily living performance, the structural relationships among these factors remain unclear. The objective of this study was to investigate the structural relationships among changes in UE motor impairment, muscle strength, motor function, and daily living activities in individuals with chronic stroke before and after intervention. The study included 131 individuals with chronic stroke in outpatient rehabilitation settings. Pretest and posttest measures were used, with the Fugl-Meyer Assessment evaluating UE motor impairment and the Medical Research Council scale measuring muscle strength. Motor function quality and speed were assessed using the Wolf Motor Function Test, while daily living function was gauged with the Nottingham Extended Activities of Daily Living Scale. Model fitting indices indicated an excellent fit. Results showed that changes in UE motor impairment negatively impacted daily living function (β = −0.188, p = .024) and motor function speed (β = −0.270, p = .001). Changes in muscle strength and motor function quality marginally influenced motor function speed (β = −0.165, p = .055 for each). Reductions in UE motor impairment directly diminished improvements in daily living function. Enhancements in muscle strength and motor function quality indirectly promoted these functions through improved motor speed, aiding in the design and monitoring of rehabilitation protocols for stroke patients.