An accelerometer is attached to the plantar surface of the large toe. The stimulating electrodes are placed along the posterior tibial nerve (posterior to the medial malleolus). Stimulation causes plantar flexion of the toes. Note the negative (black) electrode is placed distally.
Reference:
Naguib M, Brull SJ, Johnson KB. Conceptual and technical insights into the basis of neuromuscular monitoring. Anaesthesia 2017; 72 Suppl 1:16.