I am a fairly avid runner. I don't run competitively much but more for fun, fitness and to be able to eat a little more of what I want. I usually run about 3 days per week.
As a runner, I now find myself in the same position as a lot of patients I treat ... needing new running shoes! Over the last month or so I have had more aches and pains after running. I notice that within 10-15 minutes after running the front of both of my knees ache. My feet and ankles get more sore the day or so after a run also. Another major clue that I've been ignoring is that I feel every crack or bump in the pavement.
Simply put, my shoes have lost their ability to help absorb some of the shock of running. The ground reaction forces transmitted up the leg from running can be as high as four times body weight.
The amount of the ground reaction force is widely accepted and described further in this research abstract
In addition to the symptoms that I have personally been experiencing and describe, other common signs that running shoes have exceeded their useful life could include: increased muscle fatigue, onset of shin splints or plantarfascitis (arch pain), increased and uneven wear pattern on soles and decreased structural integrity of the shoe (easy to bend or twist). The typical lifespan of running shoes is 400-500 miles or about 4 months of running 25 miles per week.
Buying new shoes is not as simple as running to your nearest big box store and grabbing a pair in your size off the shelf. I am going to go to a store that specializes in running shoes and get my foot measured to ensure the proper fit. A specialty store is also more likely to be able to assist you in picking out the style of shoe that best fits your foot and running style. The three main types of shoes are: motion control, stability, and cushioning. Don't just try them on: Try jogging in them a bit. Some stores have areas or treadmills set aside for you to do this. For a good pair of quality running shoes that fits properly, expect to pay a little more. I feel that it's worth it if you run regularly.
As a physical therapist, I am a bit embarrased that I've let it get to this point because I know better. That's a bit of human nature and also a bit of an attempt to economize, as many of us are doing these days. Well, off to buy my new shoes. I'll let you know later how this worked out.