Intermuscular coherence during arm movement changes significantly with shoulder abduction and age, but not with limb dominance

We provide what, to our knowledge, is the first overall comparison of patterns of IMC in unimpaired individuals across arms and the adult lifespan to help future studies quantify and interpret disruptions in neuromuscular control. Beyond confirming the expected increase in IMC with shoulder abduction, we critically demonstrate that age significantly affects IMC in the alpha-band associated with propriospinal sensorimotor processes. We speculate this may be a result of spinal reorganization of spinal motor nuclei due to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>α</mml:mi></mml:mrow> </mml:math> -motoneurone death with healthy aging. Given the supporting evidence in this study that limb dominance does not significantly affect IMC, common drive to muscles (as quantified by IMC) is likely driven by subcortical processes that predate the neural lateralization of human upper extremity function.