Does The Achilles Tendon Injury Need Medical Attention?

My 14 year-old son strained his Achilles tendon in a rather strange manner, it seems. He was actually just walking on a basketball court between games, said he strode too far came down on his heel and hyperextended his foot. It has been sore the last 10 days. It hurts the most if he accidentally points his toe down too far in the same hyperextension manner, but it is also painful to jog slightly. We have kept him out of all activity since it happened, and we stretch and ice morning and night, traditional Achilles stretches and slant board. We have not been to see a physical therapist or doctor because I assume they would just recommend the same treatment: rest, ice and stretch. Is there anything else we should be doing? Do we need to go to the doctor/physical therapist? And is this a common injury in teenagers? I injured mine in my 40's. the time when most guys I know do. Thanks for your help.