Biological tissues are exposed to elongation forces during movement. Ultrasound shear wave elastography can simultaneously estimate the passive tension of multiple tissues during movement. The primary aim of this thesis was to test the hypothesis that extramuscular fascia transmits force from one muscle belly to another muscle belly. The secondary aim of this study was to provide a general overview of the changes in passive tension of several structures simultaneously throughout a movement. To this end we performed ultrasound shear wave elastography on the lower limb capturing data from the gastrocnemius medialis and the soleus muscles and the tibial nerve from zero to maximum hip flexion in the absence of any other joint rotation. These measurement locations were chosen as it is currently not possible to perform ultrasound shear wave elastography directly on extramuscular fascia. We designed a second component to the investigation and measured the flexor digitorum longus and soleus muscles during toes neutral and toes dorsiflexed. Gastrocnemius medialis muscle shear wave velocity increased from neutral to toes dorsiflexed (Mean Difference 1.228 (m/s) p< 0.0001) along with the tibial nerve (Mean Difference 1.504 (m/s) p = 0.0008), no change was detected in the soleus muscle during hip flexion. After toe extension flexor digitorum longus muscle shear wave velocity increased (Mean Difference 1.606 (m/s) p< 0.0001) along with soleus muscle (Mean Difference 0.660 (m/s) p< 0.0001). We concluded that extramuscular force transfer can occur from one muscle to another, although more research is needed to understand the clinical relevance of the effect and when and where this is likely to occur.