I have a feeling that Bones grounds the crew members. Like instead of telling them that they have to go on medical leave he would just shout, “You’re grounded!”
Like can you imagine Bones marching up to the bridge and dragging Jim or Spock back to Sickbay grumbling about how they had been grounded from bridge duty, and were now going to be staying in Sickbay where they would be watched.
Can you picture Bones having lollipops for his patients? I feel like it was the only way to get Jim to stop whining and to get Spock to shut up. Like Bones just shoving one into their mouths so he can work in peace, and when it works he just starts carrying them around with his wherever he goes.
But Bones won’t give them a lollipop if they don’t come to Sickbay when they are hurt. He will treat them either way, but whether or not they get a lollipop depends on whether or not they make him chase them down. And if they are “grounded” and get hurt, then they don’t get one. Even Spock starts to be more willing to go to Sickbay, as long as he receives a lollipop.