It is usual and expected to have your leg muscles and lungs burn after a hard and long run. This form of pain or ache is common when you work your muscles heavily and is part of their development process. Any other type of pain after workout is not a result of muscle activity and development and should be evaluated as soon as possible.
Many people associate running pain and injuries with body parts that are below the waist like hips, knees, ankles, etc. Because these are the most active body parts while running, it is totally understandable to have that kind of opinion. However, you would be surprised with how many runners suffer from upper back pain.
A healthy individual doesn't usually give walking a second thought – it's something we do to get from point A to point B, right?
But when you start experiencing lower back pain while walking, it suddenly stops being just a regular part of your day, and you find yourself wondering:
What's going on?