1. should i stretch my abs ?

2. i have pain in this area https://www.google.co.il/search?newwindow=1&biw=1517&bih=741&tbm=isch&sa=1&q=left+knee+pain&oq=left+knee+pain&gs_l=img.3..0j0i5l4j0i24l5.14945.17993.0.18133.19.14.1.1.1.0.233.1641.0j8j2.10.0….0…1c.1.51.img..7.12.1653.5AhlHVtkcRM#facrc=_&imgdii=_&imgrc=I_Jab26WnVGLWM%253A%3BDBuKLLShcOBDdM%3Bhttp%253A%252F%252Fwww.namemypain.com%252Fimages%252FKnee%252FKnee-03.jpg%3Bhttp%253A%252F%252Fwww.namemypain.com%252FBody_Knee_Back-C.html%3B309%3B309

it is happening when i try to sit crossed legs ,

i think it has happended because of overstretching but i dont know what to do now .

3 i didnt know that i should do this shoulder mobility this way ty very much !