Step by Step Guide
Begin in a high plank position on your hands and feet with the hands directly under the shoulders. Be on your toes with the feet hip distance apart. Have your spine in a straight line from head-to-toe.
Lift one arm straight forward with the thumb up until it is in line with the rest of your body. Be sure to maintain a neutral spine and avoid any twisting in the rest of your body.
Then, lower that hand back down to the ground.
Repeat for the desired repetitions, alternating arms.
A common mistake is allowing the back to arch. Instead, focus on keeping the spine in its neutral curvature. Pull the belly button up toward the spine to engage the abs and avoid lower back arching. Then as you raise an arm, squeeze the glutes to avoid any hip rotation.