1. From a face-down position on the floor, place your elbows directly underneath your shoulders, keeping them bent at a 90-degree angle, with your forearms extended out ahead
2. Extend your legs out so that only your knees touch the floor, bend at the knee and keep your feet either elevated from the floor, or resting on the floor from below the knee
3. Keep your body elevated, with only your knees, elbows, forearms and hands touching the floor
4. Maintain a strong, straight back with your head and neck in a neutral position
5. Drive your elbows into the floor while keeping your core strong and supported for the specified duration
The primary muscles used in the Knee Plank are the Abs. The secondary muscles used are the Shoulders.