doi:10.1152/jn.00336.2025engGraef, CosimaPascual Valdunciel, AlejandroFarina, DarioVaidyanathan, RaviTai, Yen FHaar, ShlomiPropagation of beta bursts from the motor cortex to the motor units of multiple upper-limb musclesART-2025-148517We provide the first evidence of cortical beta bursting in motor unit (MU) activity of forearm extensors across force levels. MU beta bursts are time-locked to cortical beta bursts, supporting direct corticospinal transmission in the upper limb. Our findings indicate that burst timing is robust to changes in contraction levels and demonstrate a robust cortical-peripheral beta relationship during isometric contractions. They also reinforce the utility of HDsEMG for investigating burst dynamics and refining neurophysiological biomarkers.2025http://zaguan.unizar.es/record/17004910.1152/jn.00336.2025http://zaguan.unizar.es/record/170049oai:zaguan.unizar.es:170049info:eu-repo/grantAgreement/EC/HORIZON EUROPE/101151398/EU/Implementation and validation of a closed-loop neural interface to entrain brain rhythms and reduce motor symptoms in Parkinson’s DiseaseJOURNAL OF NEUROPHYSIOLOGY 135, 1 (2025), 97-109byhttps://creativecommons.org/licenses/by/4.0/deed.esinfo:eu-repo/semantics/openAccess