How to do a proper plank
Planks are a great foundational core stability exercise to master before progressing onto more complex core exercises. Having a strong core will increase your trunk stability which helps to protect your spine and decrease risk for injury.
Keep your head, shoulders, hips, knees, and ankles in alignment with each other.
To avoid straining your neck keep your eyes on your hands out in front of you, not up at a wall.
For positioning of your arms, make sure that your shoulders and elbows are lined up.
Keep a neutral spine from head to bottom. No sticking your bottom in the air or arching your back.
Avoid shrugging your shoulders and clenching your hands together.
Remember to breath.