After watching our grandson blow the knees out of various school uniform brands, we have found Dickies to be great.  They are durable and up to the challenge of a very active boy.

This was our first year moving up to the "big boy" sizes.  One word of caution: the size 8 Dickies no longer have the adjustable waist feature that the 2-7 sizes had.  For our skinny grandson, this is essential. Other reviewers have mentioned that these pants run small - that "Slims" are too slim - but, though the slims were closer to a fit, he still needed the adjustable waist.

We wound up returning what we bought and found some uniform pants with adjustable waists at a local store.