The Effect of Heating on Tendon and Joint Blood Flow
Abstract
Current decompression sickness prevention techniques which offer only limited or intermittent perfusion of 'tight' connective tissues is the suspected reason for long nitrogen washout times. If this is the case, we propose to investigate whether heat applied to bends-susceptible joints may increase perfusion and decrease washout times. A laser Doppler probe was used to evaluate perfusion in Achilles tendons of 20 pigs, 5 dogs, and 4 goats. Baseline measurements were taken with motionless animals. Heating was then applied and resulting measurements were compared. Earlier observations that tendon blood flow shut down for extended period of time was not confirmed. In this study, there was a constant, but low perfusion of the tendons and joint capsules in all three species tested and perfusion appeared to be uniform throughout each tendon or capsule. Local heating elevated the perfusion by as much as 300% in some animals, although the elevation was not consistent or statistically significant since the laser beam observed a volume of approximately 1 cu mm, and at no time was there zero flow. It appears that even if there was local shutdown of perfusion in a small area adjacent to the one being observed, the perfusion in adjacent areas (within 1 mm) is sufficient to prevent supersaturation with inert gas and hence the formation of bubbles in these tissues. Keywords: Astronauts/ pilots; Extravehicular activity; Decompression sickness prevention.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1990
- Accession Number
- ADA225233
Entities
People
- William P. Fife
Organizations
- Texas A&M University