When running, the hips should slightly rotate in which plane?

The correct answer highlights the importance of hip movement during running. In the context of running biomechanics, the hips should exhibit slight rotation in the transverse plane. This rotation is crucial as it enables proper alignment and balance of the body while running, allowing for a more efficient stride and power generation.

When the hips rotate in the transverse plane, they facilitate smooth and coordinated movement of the legs and arms, which is essential for maintaining rhythm and stability. This rotational movement also helps in controlling the pelvis, ensuring that it does not move excessively from side to side or forward and backward, which can lead to inefficiency and potential injury.

In contrast, while the other planes—frontal and sagittal—contribute to overall body movement, they do not specifically account for the rotational motion of the hips that is integral to effective running mechanics. The frontal plane deals predominantly with side-to-side movements, and the sagittal plane focuses on forward and backward motions. The vertical plane is generally less pertinent to rotational aspects and more related to upward and downward movements. Thus, recognizing the significance of transverse plane rotation is key in understanding proper running form and technique.