Extensor Digitorum Longus is primarily responsible for which action?

The Extensor Digitorum Longus is primarily responsible for dorsiflexion of the ankle, making this the correct answer. This muscle is located in the anterior compartment of the leg and plays a key role in extending the toes as well as lifting the foot upwards at the ankle joint. Dorsiflexion involves the movement where the top of the foot moves towards the shin, which is essential for activities like walking and running, especially during the swing phase of gait.

While plantar flexion (the opposite of dorsiflexion) involves pointing the toes downward, this action is primarily facilitated by muscles in the posterior compartment of the leg, such as the Gastrocnemius and Soleus. Flexing the toes is primarily facilitated by the Flexor Digitorum Longus and other muscles that primarily facilitate toe flexion rather than extension. Adducting the toes involves bringing them closer together and is a function of the intrinsic foot muscles rather than the Extensor Digitorum Longus. Therefore, understanding the specific actions of muscle groups is crucial for interpreting their functional roles in movement and anatomy.