Ontario Grade 12 Kinesiology Practice Exam

The tibialis anterior is the primary muscle responsible for dorsiflexion of the ankle. Dorsiflexion refers to the movement that brings the top of the foot closer to the front of the leg, effectively decreasing the angle between the foot and the shin.

The tibialis anterior is located on the anterior compartment of the leg and is uniquely situated to perform this action efficiently. When it contracts, it pulls the foot upwards. This muscle is also involved in stabilizing the ankle during various activities, including walking and running.

The gastrocnemius and soleus are primarily responsible for plantarflexion, which is the opposite movement, allowing the foot to point downwards. The peroneus longus works mainly in eversion of the foot and also assists in plantarflexion but does not play a significant role in dorsiflexion.

Understanding the specific actions of these muscles is crucial in kinesiology, as it helps in recognizing how they contribute to various movements and postural control in the human body.