Deep Diving Maladies – Compression Arthralgia
by Andy Davis
Compression Arthralgia (also called compression pains) can onset as shallow as 60m/200ft but becomes more significant as depth/pressure increases.The severity of compression arthralgia is determined by the speed of descent (rate of compression), depth attained (significance of compression) and the level of diver exertion or activity. There is also a varying level of individual susceptibility.
Whilst compression arthralgia is typically associated with saturation divers at extreme depth, it must be remembered that these divers typically conduct very slow compression (descent rates circa 1m per minute). Recreational technical divers would typically encounter much higher rates of compression during air or trimix dives (descent rates circa 20-30m per minute), thereby provoking compression arthralgia at much shallower depths.
Medical science does not yet understand the physiological cause of compression arthralgia, but it is believed that a sudden onset in gas pressure within the joints causes a form of osmosis; shifting fluid from the joint lubrication to the surrounding blood.
The symptoms of compression arthralgia are as you might expect; mild to a severe or debilitating pain that can occur suddenly in any of the joints during descent. The sensation is described as a deep, aching, pain coupled with a “popping” and/or “sandpaper” sensation when moving the affected joint. Symptoms of compression arthralgia usually resolve during the decompression phase of the dive. Continued pain post-dive may indicate a physical injury of the joint caused by the compression arthralgia. Post-dive pain in the joints can be confused with Type 1 DCS, but in a case of compression arthralgia, there will be no relief of symptoms during hyperbaric treatment.
About the Author
Andy Davis is a RAID, PADI TecRec, ANDI, BSAC and SSI qualified independent technical diving instructor who specializes in teaching advanced sidemount, trimix and wreck exploration diving courses across South East Asia. Currently residing in ‘wreck diving heaven’ at Subic Bay, Philippines, he has amassed more than 9000 open circuit and CCR dives over 27 years of diving across the globe.
Andy has published many magazine articles on technical diving, has written course materials for dive training agency syllabus, tests and reviews diving gear for major manufacturers and consults with the Philippines Underwater Archaeology Society.
He is currently writing a series of books to be published on advanced diving topics. Prior to becoming a professional technical diving educator in 2006, Andy was a commissioned officer in the Royal Air Force and has served in Iraq, Afghanistan, Belize and Cyprus.