Do you want to kick your own butt? Do a lunge and squat all in one. Go to the squat rack. Use a weight that provides resistance and with which you can do four sets of ten repetitions - for each of the two leg position variation. That's eight sets! Get into lunge position. Do squats: Instead of lowering yourself as you for the standard squat, lower yourself into a lunge position.
Disclaimer: None of the above information can be taken as a substitute for advice from a medical professional, such as a physician.
My third book, Pocket Guide to Fitness, is available on www.louizapatsis.com, http://www.authorhouse.com, www.bn.com and http://www.amazon.com. If you look up my name on those Web sites, you will find my other books The Boy in a Wheelchair and Life, Work and Play: Poems and Short Stories.