Functional synergy recruitment index as a reliable biomarker of motor function and recovery in chronic stroke patients

Abstract Objective . Stroke affects the expression of muscle synergies underlying motor control, most notably in patients with poorer function. The majority studies on have conventionally approached this analysis by assuming alterations inner structures after stroke. Although different synergy-based features based assumption to some extent described pathological mechanisms post-stroke neuromuscular a biomarker that reliably reflects function and recovery is still missing. Approach Based theory synergies, we alternatively hypothesize functional synergy are physically preserved measure temporal correlation between recruitment profiles healthy modules paretic muscles, feature hereafter reported as FSRI. We measured clinical scores extracted both ULs 18 chronic stroke survivors from electromyographic activity 8 muscles during bilateral movements before 4 weeks non-invasive BMI controlled robot therapy physiotherapy. computed FSRI well quantifying inter-limb structural differences evaluated these measures scores. Main results Correlation revealed weak relationships conventional describing In contrast, values specific or combined movement data significantly correlated UL Additionally, observed BMI-based training contingent positive proprioceptive feedback led improved trained finger extension movement. Significance demonstrated can be used reliable physiological stroke, which targeted via therapies adjuvant physiotherapy boost effective rehabilitation.