Fig. 2
Representative data of torque and electromyography (EMG) signals during twitch contraction in young and older male participants and schematic explanation of measurement variables. a Plantar flexion torque, b EMG activity of the medial gastrocnemius, c EMG activity of the lateral gastrocnemius, and d EMG activity of the soleus. Black arrows represent the onset of electrical stimulation. Mmax, peak-to-peak amplitude of M-wave; PT, peak torque; RTD, rate of torque development; TPT, time-to-peak torque