Paganini was Probably Very Hypermobile (Amongst other things)
In discussing hypermobility, one must also mention that many musicians are hypermobile, for better or for worse. In looking at Niccolo Paganini, 1782-1840, many historians have concluded that he had extremely flexible joints and may have had a genetic tissue disorder known as Ehlers-Danlos syndrome. Let's backtrack for a moment- Paganini was an epic violin virtuoso doing things that people never thought possible. His caprices were written in the first 20 years of the 19th century, and pushed violin playing to a limit that was unimaginable then and still challenging now. (Left hand pizzicato 16th notes in succession? Huge extensions?) Nowadays, Paganini caprices are an expectation of elite violinists, at least in music school and training. While they are still virtuosic masterpieces, they are seen as a requirement for studying violinists. Basically, we have taken a man's unique hypermobile superpowers and expected that the rest of the violin population will gain those skills, irregardless of frame, hand size, or dexterity. Let's backtrack and look at Ehlers-Danlos for a moment.
Hypermobility throughout the body can also be a symptom of different connective tissue issues, including Ehler-Danlos, Marfan Syndrome, and Loeys-Dietz. (Some people also believe that Rachmaninoff had Marfan Syndrome, given his hands, huge span, and appearance.) On the flip side, a small proportion of the population has hypermobile joints and no other issues. Ehler-Danlos is sometimes seen as a collagen issue, and hypermobility is only one of a few different classifications of the disease, including vascular issues, skin elasticity, and many other different variations of hypermobility, including joint deformation, tendon and ligament damage, and whatnot.
In regards to Paganini, people at the time described his ability to span multiple positions without shifting, an ability to contort his hand to extreme positions, and how as he aged, he practiced less, possibly because of pain (osteoarthritis). Will we ever know if he really had these connective tissue diseases? Not really, unless someone exhumes him and does some genetic testing. But the next time you're practicing something made for a body much different from yours, it might be worth asking the question of whether it's worth it and what the real payoff is if it's painful...