The practice session last night brought back memories of training in Ayrshire years ago. I was the human punchbag (with pad protection) - although I really don't mind it. It actually teaches you to relax. If you are tense, being hit hard through a pad will still cause damage.
Last night the class lined up in front of me holding the pad against my quad, taking turns to kick it full force. Most of the kicks were strong but my relaxed leg held out, with one exception. A random, average kick that seemed to 'go through' the pad. Maybe I momentarily tensed my leg, I'm not sure but I felt this morning!
When I was practising as a teenager in Ayrshire, I was the biggest guy there, so was always called forward for the sensei to demonstrate how hard you can hit someone with technique rather than brute force. It was always sore through the pad.
Unbelievably, you can feel the force of a strong punch through 12 people! This was part of another demonstration at a course. Thankfully, on this occasion, I wasn't the person with the pad at the front...