The London Olympics are off and running. Jerry Tegenkamp would love to be there, matching the thousands of spectators stride for stride.

At 73, his legs won’t allow it.

“There would be a lot of walking,” he said. “I can’t do that anymore.”

Thus, come 3:15 next Saturday afternoon, Tegenkamp will turn on the television at his home in Normal and watch the men’s 10,000-meter run, uninterrupted and undeniably proud...