Harness Suspension Stress: Physiological and Safety Assessment.

Hanging motionless in a full body harness may result in unwanted events, such as acute hypotension and syncope, which has been termed harness suspension stress (HSS). The etiology of HSS has not been explored, and it is unknown if the type of harness influences the HSS response.Objectives:Evaluate hemodynamics, subjective discomfort, and biological markers of muscle damage during 30-minutes suspension; and evaluate differences between harness attachment (frontal or dorsal).Methods:Heart rate, blood pressure, biological markers of muscle damage, and subjective discomfort were measured.Results:Trial time was shorter in the dorsal versus frontal point of attachment. Hemodynamic shift resulted in the dorsal trial which indicated possible perfusion abnormalities.Conclusions:Hemodynamic adjustments contributed to early termination observed in the dorsal trial. A frontal point of attachment may be more suitable for extended harness exposure.