Figure 1

Grasp-and-lift task and InfoMuNet overview. (a) Electromyographic signals were recorded from eight muscles on each limb: Abductor Pollicis Brevis (APB), First Dorsal Interosseous (FDI), Flexor Digitorum Superficialis (FDS), Extensor Digitorum Communis (EDC), Flexor Carpi Ulnaris (FCU), Extensor Carpi Radialis Longus (ECRL), Upper Trapezius (UT), and Lower Trapezius (LT). The median InfoMuNet (i.e., the connectivity network of median mutual information between muscle pairs) across all subjects and trials indicates that the less-affected limb has the strongest connectivity during the grasp-and-lift task. The post-exposure affected shows stronger connectivity trends than the pre-exposure affected limb, highlighting the potential effect of sensorimotor exposure. sEMG plots are representative activations for each muscle. (b) For each trial, the task consisted of grasping the instrument with the thumb and index finger and lifting the instrument. (c) The experiment was completed in two separate sessions. Subjects performed the task with the affected limb only (pre-exposure affected) in the first session. Subjects performed the task first with the less-affected limb followed by the affected limb (post-exposure affected) in the second session. (d) The task was performed under eight sensory conditions. Subjects completed 14 trials for each sensory condition for a total of 112 trials (14 trials × 8 sensory conditions = 112 trials). (e) Mutual information I(X; Y) between signals from any two muscles is computed using the individual entropies H(X), H(Y), and joint entropy H(X, Y). I(X; Y) was quantified between all muscle pairs to form the InfoMuNet for each trial.