Relationships between arm and leg real-life activity and clinical assessments in individuals with disabling spasticity after stroke

Background Accelerometer-based measures can provide valuable and objective information about arm and leg use in daily life. This information can be particularly useful in tailoring treatment and rehabilitation in people with disabling spasticity after stroke. To better understand clinical relevance of accelerometer-based measures, this study aimed to determine the strength of relationships between real-life arm and leg activity and a set of clinical assessments encompassing body function and activity domains. Methods Thirty-five individuals with disabling spasticity in the chronic stage of stroke (mean age 56.8 ± 8.9 years; 54% female) were included. Real-life activity was measured over 4 days using wrist- and ankle-worn accelerometers. Unilateral arm and leg activity as well as arm/leg ratio were derived from vector magnitude counts per minute. Associations between accelerometer-based measures and clinical assessments of motor function, spasticity, activity capacity, and self-perceived activity performance were analyzed using Spearman's rank-order correlation. Results Affected arm and leg real-life activity showed mostly moderate correlations with motor function and activity capacity assessments (ρ = 0.55–0.76), low correlations with spasticity assessments (ρ = −0.32 to −0.43) and high correlations with self-perceived manual and walking performance (ρ = 0.70–0.82). Arm activity ratio showed high correlations (ρ = 0.73–0.83) with motor function, activity capacity, and self-perceived performance. Real-life activity of the non-affected limbs demonstrated predominantly low correlations with clinical assessments. Conclusion Accelerometer-based real-life activity measures of the affected arm and leg, along with activity ratios, provide clinically valid information regarding motor function and activity in people with disabling spasticity. Self-reported activity performance questionnaires can be valid tools for clinical practice when accelerometer-based measurements are not readily available.