Not sure if the spring-and-latch mechanism is behind cats’ jumping ability — I don’t readily find any science on that. Your comment about running is interesting. I ran wrong for years (mostly 5ks and 10ks in triathlons) until a coach taught me how to do it correctly, landing on the balls of the feet as they sweep backward rather than plowing into the ground with heel strikes. It took some getting used to but instantly shaved several seconds off my 1-mile training intervals, and it uses less energy so has a compounding effect across a 10k. Again tho, not sure that could be described as spring-and-latch. But either way, fun to ponder!