With the rapid miniaturization of physiological sensing components and the widespread adoption of wearable devices, long-term physiological monitoring has become increasingly feasible in daily life and sports applications. In this study, we initially analyzed data from a conductive-fabric-based electromyography (EMG)-like sensing sleeve. The developed sleeve employs textile electrodes to emulate surface EMG sensing and integrates six sensing channels, with a small amount of water applied to enhance electrode conductivity. Compared with conventional adhesive EMG systems, the textile-based sleeve is easy to wear and effectively mitigates electrode displacement during high-speed baseball pitching motions. Experiments on three representative movements demonstrate that the proposed sleeve reliably captures muscle activity, instilling confidence in its practical use for sports training and biomechanics analysis.