The legs look normal to me--his movement IS sloppy, front and rear, though some of that can be attributed to the flexi-lead; if you can get some video of him walking and/or trotting off lead, we would see a truer display of his natural movement.
He is cow-hocked, and very loose-ligamented at the moment, but he's also only 8 months old and still has a significant amount of growing to do, along with developing more muscle tone with increased exercise. As to the comments regarding the quality of the dog, one has to first know where the dog is located. In some countries he could well be one of the very best young dogs on the horizon; for example, he is not unusual among well-bred specimens of the breed in India at the moment, while in Germany this young dog would not be considered a show ring and breeding prospect and would be sold as a family pet.
All that said, if your concern, Khalid, is whether there is something medically wrong with this young dog, nothing in this video would indicate such; it's possible he could have bad hips or elbows, but nothing about him tells us that from the video...you'll need x-rays to make that determination.
He does have beautiful pigment and markings, and is an attractive youngster who looks like he's a spirited fellow as well. I wish you all the best with him.