Stroller ride gone bad

Yesterday, after being turned down on their offer to take Ben on a stroller ride, Regan and Spencer decide taking Spencer for a ride would be the next best thing. Not long after, we hear screaming, and it's getting closer. From the sound of it, someone has surely lost a limb.
Spencer bursts through the kitchen door and collapses on the floor. I see no visible signs of damage, but judging from the agony in his screams, it must be serious. Perhaps internal bleeding, I'm thinking. Clearly he's mere inches from death.
But wait! This is Spencer we're dealing with. So everybody just take a deep breath. He's not dying after all. Jason holds him on his lap until he's recovered enough to give us the story.
He was inadvertently launched from the stroller when Regan failed to steer clear of an uneven section in the sidewalk while running at full speed.
So after all this, what was the damage? If you scroll down to the bottom picture you may be able to see (if you click on the picture to view the full size) the skin that was so tragically skinned from his knee.
And these are the same boys that wanted to take Ben for a ride? No wonder Ben prefers to hang out with Mom!