My son has experienced this 3 times in the last 18 months, sore calves resulting in inability to stand walk for a week or so, elevated CK in 1,000's on two occassions (not the latest attack) and then returns to normal. Interestingly, walks on tip toe toward the end of recovery. Our son is otherwise a normal active 7 year old, however does tend to get more tired than normal after activity occassionally. We are currently seeing a Neuromuscular specialist and our son is scheduled for a muscle biopsy in the coming weeks in an attempt to identify cause.View Thread