Differences in Plantar Flexor Fascicle Length and Pennation Angle between Healthy and Poststroke Individuals and Implications for Poststroke Plantar Flexor Force Contributions

Figure 1

Longitudinal ultrasound image of the lateral gastrocnemius muscle. Top solid yellow line marks the superficial aponeurosis and the deep solid yellow line marks the deep aponeurosis. 𝐿^𝑓 follows the fascicle length from deep to superficial aponeuroses, and 𝜃 is the angle between Lf and deep aponeurosis.