Man Bravo style tore up my hips and my knees because I naturally have tight hip flexors and ITBands. I feel your pain

Here is a page that's specifically about hip flexor inflexibility-
http://www.exrx.net/Kinesiology/Inflexibilities.html#anchor30863
http://www.rice.edu/~jenky/sports/itband.html
http://www.hksi.org.hk/function/triathlon/stretch4.htm
and my personal favorite-
http://www.exrx.net/Stretches/GluteusMaximus/Lying.html
Also, try getting a stretching band. They help immensely with flexibility and you can do a wide array of partner type stretches without a partner because of these bands. I tried to find a link but I actually couldn't find one cuz I'm short on time. Just remember to always warm up your muscles before you stretch them! And warm up then stretch first thing in the morning, too.. it'll make you wake up real well and help with flexibility :)