To go along with what Kaitlin is saying, also check the heel drop in his shoes. We should all be in shoes that are pretty flat from heel to forefoot. Say no to flip flops as well. I know with my 9 year old, he complained of some mild heel/ankle pain about 6 months ago. I switched him to a lower heeled shoe and he quit talking about it. Its funny when he wears the old ones to go play in the woods he will complain about how high the heel feels.

Travis from MWOD staff here. To continue off what Phil suggested, using a softer grippy ball across the heel and up and down the sides of the shin and calf to relieve any tension in the soft tissues should be helpful. Think about getting some balls from Jill Miller at Yoga Tune Up, they are very good for the feet. I would also pay attention to your foot position while you drive. I like to tell people if you walk with your feet straight ahead, you should try to drive with your foot straight over the pedal as well. We all tend to adopt the duck foot position when we drive. See if this helps next time you have to travel a lot.