A question about engaging the starter while the propeller is turning. I went to start the airplane and I was having a little difficulty getting it started. I turned the key which obviously engaged the starter at that point and as the engine acted like it was starting to catch I released the starter (but it hadn't quite started) it was still trying to light so I opened the throttle a little bit trying to get it started. As I was doing this, I turned the key for just a second to try to bring the starter back in for assistance. It eventually started after I opened the throttle a little more. The question is, is there anyway that by turning the key for literally just a second to engage the starter while the propeller was already spinning (but before the engine was started), could have caused any damage? The aircraft is a Cessna 172.