I think we have to be cautious in advising against wearing of PPE.
If you jump on Google Scholar and try a few searches, you'll see there isn't a lot of evidence in the literature on the extent and specific types of injury; but there are studies that refer to the influence of environmental factors (and some make mention of contacting hard objects as a cause of injury).
publications.waset.org/7011/pdf "Kitesurfing is a sport where injuries occur to an extent of 5- 7 times per 1000h of practising during recreational kitesurfing, according to this and earlier studies. • The lower extremities (knee and ankle) were the most frequent locations of injury, but rib fractures and shoulder injuries were also reported frequently. • Jumps and tricks were associated with about 40% of the injuries reported in this study and many were also influenced by environmental factors or equipment issues. • Physical, environmental and mental factors determine the participant’s ability to perform well and avoid injury. Many of these factors cannot be controlled, but specific physical training, practising techniques and being aware of environmental conditions have positive effects on both performance and avoiding injury. • This information can provide a foundation for further studies of kitesurfing and complements the earlier studies. A prospective study of kitesurfers of different levels of competence would be useful to obtain more detailed information on injuries and their causes, connected to specific elements of kitesurfing."
As they often do, the researchers highlight the need for more studies
europepmc.org/abstract/med/22824840 I wonder if manufacturers contributing to a research fund would be an effective way for them to give back to developing a culture of safer practice in the sport?
In relation to the "physics" discussion yesterday, I wasn't able to find the follow up studies mentioned in this project which may have offered us some actual evidence around the biomechanics involved in the sport
www.diva-portal.org/smash/get/diva2:239141/FULLTEXT01.pdf Finally, I think it's worth observing that this recent small UK study comes out of the neuroscience/neurology literature...meaning there has been enough kitesurfing/kiteboarding related head injuries for the team to consider the topic worth of research
tra.sagepub.com/content/16/1/23.short
Full study here tra.sagepub.com/content/16/1/23.full.pdf+html
"All of the injuries resulted from high energy impact with land rather than in the water and represents an area for future safety guidance"
It would be VERY interesting and useful to hear what these people have to say about the merits (or otherwise) of us wearing helmets!