The uppercut is a great punch to illustrate what I was talking about. Uppercuts require less form, it’s more about sheer power. You don’t require the weight behind you, since you’re pushing directly against the ground, which is immovable. It’s like doing a bicep curl. Your weight and position relative to the ground does not need as much balance between ground and target. You basically become as heavy as the ground itself, so your punch is now only limited by how much power your muscles can generate as they push directly opposite the weight of the ground.