title: Local Pressure Application Effects on Discomfort, Temperature, and Limb Oxygenation.
abstract: BACKGROUND
  Despite significant investment into the development and improvement of military helicopter seat systems, military aviators continue to report seat system related pain and discomfort during prolonged missions.
  
  
  METHODS
  Using a factorial repeated measures design, 15 healthy subjects completed the study, in which focal pressure was applied to two locations on the sitting surfaces of the body (ischial tuberosity and middle of the posterior thigh). Pressure was applied using a purpose-built pressure application system allowing subjects to sit in a position mimicking the sitting position in the UH-60 Black Hawk helicopter. The researchers measured pain using the Category Partitioning Scale and McGill Pain Questionnaire and vascular function using dynamic infrared thermography in the lower leg and pulse oximetry at the great toe. Data were collected before and during a 10-min application of focal pressure applied to either the ischial tuberosity or middle of the posterior thigh and at two different pressure magnitudes (36 or 44 kPa).
  
  
  RESULTS
  We found that during a 10-min pressure application, superficial skin temperature increased by 0.61°C, suggesting a decreased venous return during pressure application. We found that lower extremity blood oxygenation remained unchanged during pressure application. Subjects' reported pain increased during pressure application and was greater with 44 kPa of application compared to 36 kPa.
  
  
  CONCLUSIONS
  These results support the hypothesis that locally high pressure creates symptoms of discomfort and paresthesia. Research examining the effects of local pressure application on physiological and neurological function is needed. Games KE, Lakin JM, Quindry JC, Weimar WH, Sefton JM. Local pressure application effects on discomfort, temperature, and limb oxygenation. Aerosp Med Hum Perform. 2016; 87(8):697-703.
authors.affiliation: Department of Applied Medicine and Rehabilitation, Indiana State University, Terre Haute, IN, USA.
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Games
authors.forename: Joni M
authors.initials: JM
authors.lastname: Lakin
authors.forename: John C
authors.initials: JC
authors.lastname: Quindry
authors.forename: Wendi H
authors.initials: WH
authors.lastname: Weimar
authors.forename: JoEllen M
authors.initials: JM
authors.lastname: Sefton
mesh_terms: D000328:Adult; D000401:Aircraft / Q000295:instrumentation*; D002081:Buttocks; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D010092:Oximetry; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement; D010292:Paresthesia / Q000503:physiopathology; D011187:Posture / Q000502:physiology*; D011312:Pressure; D012881:Skin Temperature; D013848:Thigh; D055815:Young Adult