Which core exercise is classified as a multi-planar exercise?

The modified side plank with hip external rotation is classified as a multi-planar exercise because it engages multiple planes of motion—specifically, the transverse plane due to the rotation of the hips while maintaining a stable core. This exercise not only requires lateral stability, as seen in a traditional side plank, but also incorporates rotational movement, making it a challenging and effective way to work the core muscles.

By focusing on both stabilization and rotation, it actively engages various core muscle groups, enhancing overall strength and coordination. This contrasts with some of the other options, which may primarily focus on either stability or movement in a single plane without incorporating the same level of rotational challenge. Multi-planar exercises are valuable in functional training, as they replicate the complexities of real-life movements and enhance athletic performance.