This is one of the areas in which I often see unjustified concern and intervention. It starts with the preschool alerting parents to the fact that their child is lagging behind in physical activities. Jimmy doesn’t jump as well as the other kids. He still climbs the stairs one by one. He doesn’t run with as much ease as he supposedly should.
Muscular strength and coordination differ widely among kids. Clumsy children are usually able to jump, climb, and run, but a little less skillfully. Chubbier toddlers have to deal with extra mass, which impairs their range of motion somewhat. No need to worry; this awkwardness does not correlate with their future abilities in any reliable way.
If Jimmy is clumsy but your doctor has not found any major motor deficit, you needn’t intervene with occupational therapy. Just send your solid little citizen off to a good soccer league, and you’re sure to see improvement when he’s ready.