Whenever possible and practical, it's best to stop and put ice or a cold pack on that type of injury, immediately. It'll help minimize swelling and pain. Not really practical to carry for joggers, hikers or cyclists. And often there's a nearby store or restaurant for ice. Next best thing is an elastic wrap, although those can be tricky to use properly to get just the right pressure without being uncomfortably tight.

Reminds me, I need to add an elastic wrap back to my bike's first aid kit. I took it out to make room for other stuff, but need to make room for the elastic wrap too. I fell on my left side twice in March and finished both rides (about 5-7 miles) but could have minimized some of the swelling and discomfort if I'd packed the elastic wrap rather than just gauze.