You can promote lower body strength by squatting in front of a sturdy chair.
Keep your arms in front of you and be sure not to extend your knees past your toes as you bend to an almost-sitting position.
Hold the position for a few moments, then raise yourself back to a standing position, take a breather, and repeat for two sets of 10 reps.
Hold onto the sides of the chair or place a few pillows on the chair if the exercise is too challenging.