Abstract
Several studies have investigated muscle rigidity using SWE. However, the assessments may not consider the most affected regions within the same muscle tissue nor the intramuscular variability of rigidity between muscles of the same muscle group, e.g., plantar flexors. The data presented in this article aimed to explore the inter-and intramuscular variability of plantar flexors stiffness during prone and standing positions at different muscle lengths in healthy and paretic individuals. Shear wave ultrasound images were acquired for the three plantar flexor muscles (gastrocnemius medialis [GM], gastrocnemius lateralis [GL], and soleus [SOL]) in two positions: prone and standing. The imaging was conducted at various dorsiflexion angles (0°, 10°, and 20°), and measurements were taken at different proximo-distal regions within each muscle. This data set allowed us to highlight the impact of stroke on mechanical properties that varies depending on whether ankle muscles are in an active or passive state during dorsiflexion. Additionally, the modification of the ankle muscle state influences the distribution of stiffness both within and between the plantar flexors.