Modified Knee Bends Make an Appointment Ask a Question Search Conditions How this helps: It improves and maintains strength in your hips and knees. How to do it: Use a dining room or kitchen chair for this exercise. With a straight back, and your arms crossed over your chest, tighten your stomach muscles and lean slightly forward as you stand up. Return to sitting and repeat 10 times. Work up to a total of 20 repetitions. Blow air out as you stand up and breathe in as you sit down. If you can't do this exercise with your arms crossed over your chest, start by reaching forward and out as you stand. As your legs get stronger, cross your arms over your chest to increase the challenge. This information has been approved by Kimberly Sack, MS, PT (May 2012).