[header] How to do abdominal crunches with angled heels [title] Lie down facing the ceiling with your knees bent and your shoulders, hips, and feet aligned. [step] Flatten your back and clench your abs, clasping your hands together behind your head. [title] Raise your toes up so that your heels press into the ground. 
[step] This should work your upper thigh muscles; if you do not feel the effort there, try pressing a little harder. [title] Bring your head and shoulders up towards your hips in a typical crunch motion.