1. Sit upright on floor with arms straight and fists on floor under shoulders.
2. Press fists through floor, lifting your hips off the ground a couple of inches.
3. Return to start position and repeat the prescribed number of repetitions.
Be sure to: Keep chest up and shoulder blades back throughout movement. Keep arms straight. Movement can also be performed sitting on the edge of a bench or chair.
You should feel it: Working your shoulders.