People are advised not to run because it will ruin their feet and knees. In 45 years, I have run more than 240,000 miles without any major problems, and with more than half that distance covered on so-called hard pavement. Have I been lucky? No. I have merely employed correct technique, as described, and have been careful about the shoes I wear.
There are few accidents in athletics if a runner is successful (whether in terms of Olympic medals or just years of injury-free running), and there is a reason for this success. The most significant element is correct technique (made possible by good shoes). There is a lot more to running correctly than just getting your feet and legs working properly, however. What you do with your hands and arms is equally important. I have heard a number of well-known coaches tell runners that it doesn't matter what they do with their arms. My response is to ask them if it is okay if I run with one arm behind my back and the other between my legs. They look at me as if I've lost my marbles. Then I put both hands over my head and ask: "Is this okay?". Or, I'll put my hands on my ears and ask: "How about this?" If none of these methods of carrying your arms is correct, and if we eliminate all the incorrect ways of using your upper body and arms (reductio ad absurdum in mathematics), we logically should arrive at something that works very well indeed.
The best way to get a clear idea of how to use your hands and arms is to watch what the best runners in the world are doing with theirs. You will not find sloppy technique among the vast majority of the best runners. In any sport, the athletes we most admire are those who have the capacity to make everything they do look easy. The champions have an appearance of economy of movement which gives an illusion of ease. Those who are at the top are making maximum use of their bodies with powerful action. The way the human body is designed and put together demands that certain criteria be met for it to function the way it is supposed to. While it is important to take into account individual differences, the basic biomechanics required for maximum speed and efficiency will be the same for every runner. All humans have joints which bend the same way, and similar muscle elasticity and blood viscosity.