Introduction
Hanging freely and motionless in a harness produces harness suspension stress (HSS) and may cause symptoms of pain, nausea, numbness, or syncope. The etiology of symptoms has not been well defined or understood, leaving medical providers without a good rationale for possible treatment.
Objective
To evaluate biomarker shift while inducing HSS.
Methods
Eighteen healthy volunteers were recruited (men = 9, women = 9). Each subject was prescreened with a questionnaire and tilt table test. A treadmill maximum oxygen consumption test then was performed, and skin fold measurements were obtained. Subjects were randomized to front point or dorsal point of attachment for HSS testing and subsequently crossed over to the other point of attachment on a different day. Blood labs were performed pre- and post-testing. Electrocardiography, vital signs, calf girth, distal pulses, and sonographic evaluations were performed during testing.
Results
Ten subjects experienced no symptoms. Six subjects with a dorsal point of attachment and 2 subjects with a frontal point of attachment experienced symptoms before 30 minutes. Symptoms were variable. No evidence showed aberrant blood marker shifts.
Conclusions
There is no strong evidence to support current theories regarding the mechanism of symptoms from HSS. Further investigation is warranted.