Believe, Trust
You say to your leader, “Believe and trust in me, I’m responsible.” The leader doesn’t think you can handle your duties, so this is why you said this to him. You want him to believe and trust you. You can handle this task.
Imagine yourself saying this to your leader. Say it out loud as you imagine saying it to a leader of some sort.
しん
None
None
To show you are serious as you say, “Believe and trust in me, I’m responsible,” you kneel down on each shin (しん). You have shin splints, so it hurts a bit, but you do it anyway to show how serious you are.
Picture yourself pleading with your leader to trust and believe in you. Imagine the hurt of your shins with the shin splints as you kneel. It hurts a lot, but it proves how serious you are.