Try this simple routine at home!
Stand in front of a chair, your back facing the seat of the chair, feet shoulder width apart, hands to your side.
Reach back with buttocks as if you were sitting down. As soon as you touch the seat stand up again. Your hands come up at chest level while you are sitting down and they return to your side as you stand up. Repeat 20 times.
Take a 30 seconds break and repeat. Alternate rest and sitting squats 4 times.