Concurrent deficits of soleus and gastrocnemius muscle fascicles and Achilles tendon post stroke

lished February 6, 2015; doi:10.1152/japplphysiol.00226.2014.—Calf muscles and Achilles tendon play important roles in functional activ-ities. However, it is not clear how biomechanical properties of the uniarticular soleus (SOL) and biarticular gastrocnemius muscle and Achilles tendon, including the fascicle length, pennation angle, and stiffness, change concurrently post stroke. Biomechanical properties of the medial gastrocnemius (GM) and soleus muscles were evaluated bilaterally in 10 hemiparetic stroke survivors using combined ultra-sonography-biomechanical measurements. Biomechanical properties of the Achilles tendon including the length, cross-sectional area (CSA), stiffness, and Young’s modulus were evaluated, together with calf muscle biomechanical properties. Gastrocnemius and SOL con-tributions were separated using flexed and extended knee positions. The impaired side showed decreased fascicle length (GM: 6%, P 0.002 and SOL: 9%, P 0.03, at full knee extension and 0 ° ankl