Electrospinography (ESG) has recently emerged as a growing field of investigation focused on spinal cord neuronal activity, explored through both invasive and non-invasive recording approaches. Although non-invasive ESG is gaining attention for its potential in experimental and clinical settings, most existing studies have concentrated on somatosensory processing, leaving motor-related applications largely unexplored. In contrast, electromyography (EMG) is a well-established technique for characterizing muscle activation, force production and fatigue during movement. Combining EMG and ESG may therefore offer complementary insights into peripheral and spinal contributions to motor control. In this study, EMG and ESG signal power has been characterized and compared during isometric wrist flexion and extension in two able-bodied participants. High-density electrode arrays recorded EMG from forearm muscles and ESG from brachial and lumbar spinal regions, while a robotic wrist device ensured standardized task execution. Signal power was quantified using the Stockwell transform across predefined phases of a trapezoidal force profile. EMG signals showed clear distinctions between flexion and extension, with higher activation in primary agonist muscles and greater variability during extension. ESG signals also exhibited task-related modulation, including increased power during force generation and movement-dependent differences, although with smaller magnitude than EMG. These findings indicate that ESG captures spinal activity associated with motor tasks and may complement EMG in the assessment of neuromuscular control. This work supports the potential of ESG as a non-invasive tool for studying spinal contributions to movement and motivates further investigation in larger cohorts and dynamic tasks.