Side Plank from the McGill Big Three

A modified side plank from the McGill Big Three: start on your side with knees bent about 30–40 degrees and feet stacked, brace through the floor with the lower arm, and lift the hips off the ground while keeping the torso rigid. This version is used to build core endurance and spinal stability with less shear stress than a full side plank, making it a common rehab-friendly anti-extension/anti-lateral-flexion drill.