Is he just running funny?

Louie for the past few weeks has been running strange. It's not his back end which I feared with him having half lab in him, it's his front end. He'll be playing with his friend Lola and then when I see him running (recall) his front end looks funny, now it's either me being paranoid and worrying too much or he's having growth spurts that sometimes cause him to limp a little.

He isnt stiff at all around his back legs, but his front legs stiffen up sometimes - he is due for another check up at the vets soon but in the meantime is there anything it could be?

Has anyone else had any trouble with lab crosses front legs?

My OH reckons it's just his gait and there's nothing wrong but I'm a worrier so I just want to be sure