biostudies-literatureCavanagh SKBLRD VANICHD NIH HHSRRD VANINDS NIH HHSNational Institutes of HealthDepartment of Veterans’ AffairsNIGMS NIH HHSNational Science Foundation639-652https://www.ebi.ac.uk/biostudies/studies/S-EPMC12324962biostudies-literatureUnknown39(8)BackgroundVariability in movement is critical for performance under dynamic conditions. Stroke causes focal injury to the motor system, disrupts voluntary motor control, and leads to less smooth and more variable upper extremity movements. Few studies have characterized trial-by-trial variation in upper extremity movement smoothness and its clinical and neuroanatomic correlates in the first week post-stroke.ObjectiveTo evaluate trial-by-trial variation in upper extremity movement smoothness during planar reaching and relate it to clinical outcomes and neuroanatomical injury after acute stroke.MethodsTwenty-two patients (4.4 ± 1.7 days post-stroke) and 22 able-bodied adults completed a planar center-out reaching task. Smoothness was quantified with spectral arc length (SPARC). Median and inNeurorehabilitation and neural repairTrial-By-Trial Variation In Upper Extremity Movement Smoothness After Acute Stroke Relates To Clinical Assessments And Corticospinal Tract Injury.PMC12324962IK2 RX004237R01 NS12057923451071IK2RX004237IS1 BX004387IK6 RX003075K6RX003075NIH-R37-HD087089P20GM109040ShEEP BX004387-01R37 HD087089NIH-R01-CRCNS-NS120579P20 GM109040Cavanagh SKWalsh CDusang ANGochyyev PHamilton TSternad DNayeem RDiCarlo JAKautz SAHochberg LLin DJfalseTrial-By-Trial Variation In Upper Extremity Movement Smoothness After Acute Stroke Relates To Clinical Assessments And Corticospinal Tract Injury.BackgroundVariability in movement is critical for performance under dynamic conditions. Stroke causes focal injury to the motor system, disrupts voluntary motor control, and leads to less smooth and more variable upper extremity movements. Few studies have characterized trial-by-trial variation in upper extremity movement smoothness and its clinical and neuroanatomic correlates in the first week post-stroke.ObjectiveTo evaluate trial-by-trial variation in upper extremity movement smoothness during planar reaching and relate it to clinical outcomes and neuroanatomical injury after acute stroke.MethodsTwenty-two patients (4.4 ± 1.7 days post-stroke) and 22 able-bodied adults completed a planar center-out reaching task. Smoothness was quantified with spectral arc length (SPARC). Median and in2025-01-01T00:00:00Z2025 Aug2026-04-12T15:14:26.079Z2026-04-07T13:17:44.103ZS-EPMC123249624044852510.1177/15459683251340916