A baseball swing is in what plane of motion?

A baseball swing occurs primarily in the transverse plane of motion. The transverse plane divides the body into upper and lower sections and is associated with rotational movements. During a baseball swing, the torso rotates around the spine, allowing the player to generate power as they follow through with their swing. This rotational aspect is characteristic of movements in the transverse plane, making it the correct choice.

The sagittal plane involves forward and backward motions and is not representative of the side-to-side rotation involved in a swing. The frontal plane is concerned with movements that occur side to side, such as lateral arm raises or side lunges, which do not align with the rotational nature of a baseball swing. The term "parallel sagittal" is not commonly used in biomechanics and may confuse the context, as this suggests a motion maintaining a forward-backward alignment, which is not what occurs in a baseball swing. Understanding that the swing's mechanics involve rotation about an axis is key to recognizing the dominance of the transverse plane in this movement.