This is not really about an injury, but about a very interesting physiology fact that I recently discovered that pertains to badminton, in a way. The palmaris longus is a muscle on the inner forearm that is involved in wrist flexion and pronation. It is said that up to 25% of people don't have this muscle. I wonder how much this relates to how hard someone can hit a shuttle cock? https://journals.sagepub.com/doi/10.1016/j.jhsb.2005.05.003
Was curious so just read up on some research studies on this. Having/not having the muscle doesn't affect overall grip strength. But there does seem to be a difference when pinching with the 4th and 5th finger.
Yes the research mentions grip, but it doesn't mention flexion or pronation. Basic physics suggests that an extra muscle on the inner forearm where the palmaris longus is would increase flexion strength/speed of the wrist.
Yes, I can see how this would be true. It might give a slight advantage in wrist flexion. However, I view badminton wrist speed as primarily involving pronation and supination which doesn't seem to utilize this muscle.