Wall lean piston hold ("Wall lean piston" Core/lower extremity strengthening isometric)

Stand up straight facing a wall.
Place the palms of your hands on the wall at shoulder height.
Ensure your palms are shoulder-width apart.
Step your feet back so that you have a straight line from the tip of your head to your heels.
Tighten your abdominal muscles and buttock muscles to maintain this shape.
Draw one knee up towards your chest until your hip and knee are at a 90-degree angle.
Hold this position.