Everybody is shaped differently; not one person has the same body as the other person. However, there is a way to make sure your form is proper when you run so that you do not injure yourself. It was helpful for me when I ran track because I had people watching me run and letting me know what my form looked like, and if I needed to critique anything.
The first thing to think about when it comes to your form is head tilt. How you hold your head while you’re running can be the key to your overall posture. You should look up and ahead while you run, not down at your feet. This will straighten your neck and your back alignment.
Next, you should think about your shoulders. This is something I had an issue with. In order for your run to be efficient, your shoulders need to be low and loose, not high and tight; your upper body should be relaxed. If you start to get tired and feel your shoulders tighten up, try to shake them out and relax them.
If I remember anything from when I ran track in high school, is my coach telling us to relax our hands while we run. They should be in an unclenched fist, with your fingers barely touching your palm. This will help keep your arms relaxed and loose. Your arms help control the strides you take. They should be moving forward and backward, not side to side.
With your head and shoulders in place, this will help your torso be in proper alignment, along with your hips. This will put your body in the proper form.
These little things will simply help improve your performance, as well as the way you feel while going for your runs.