I examined the rock climber in clinic this past week who had failed PRP injections into his Achilles tendons. After seeing another provider in an orthopedic practice and getting 5-6 PRP injections, he was still unable to run due to heel pain. The reason? Nobody looked at whether a pinched nerve in his low back might be causing his Achilles tendon pain. After seeing him this week for his third Regenexx-PL-Disc procedure, he’s now back to running with his right ankle completely pain free and his left well on the way. How could his low back cause his Achilles tendon problems? For a more complete explanation, see our medical practice’s book, Orthopedics 2.0. However, briefly, an irritated S1 nerve in the low back can mimic an Achilles tendon problem. First, if you look at the dermatome map above and follow where the S1 low back spinal nerve goes, it travels down toward the back of the leg and heel. So if I could reach in and pinch your S1 back nerve, you would feel it in the back of your heel. Second, the nerve also powers the calf muscle, so an irritated S1 nerve in the back causes a dysfunctional calf muscle. This muscle is attached to the Achilles tendon, which then begins to develop issues. We’ll continue to follow YSL, but it’s great to see that a more comprehensive look at his Achilles tendon problems beyond just PRP injections in his Achilles tendons is helping him get back to what he loves to do!