National Physical Therapy Examination (NPTE) Practice Exam

The typical plantarflexion range required for running efficiency is indeed between 20° and 30°. This range is crucial because adequate plantarflexion allows for a proper push-off during the running gait cycle, contributing to effective propulsion and enhancing overall running speed.

When the ankle is positioned in this range, it enables the calf muscles, particularly the gastrocnemius and soleus, to generate the necessary force to propel the body forward efficiently. Additionally, maintaining this level of plantarflexion helps to optimize the biomechanics of the lower extremity, reducing the risk of injury and improving performance.

In running, excessive plantarflexion can lead to decreased stability and control, while insufficient plantarflexion may not provide enough force for an effective push-off. Thus, a range of 20° to 30° is often identified as optimal for the mechanics of running, supporting both speed and endurance.

The other ranges mentioned do not align with the biomechanical requirements for efficient running. For instance, lower ranges such as 10°-20° may limit the force output necessary for propulsion, while higher ranges like 30°-40° could potentially interfere with balance and stability during dynamic movements.