Various Ischemic Preconditioning Pressures Do Not Impact Pain Pressure Threshold Or Tolerance Responses

PURPOSE: Ischemic preconditioning (IPC) at high occlusion pressures has been reported to induce a hypoalgesic effect via the release of endogenous opioids. It has not been determined if moderate pressures also exhibit a positive effect. The purpose of this investigation was to examine the acute effects of IPC at low, moderate, and high pressures on pain pressure threshold (PPTThreshold) and pain pressure tolerance (PPTTolerance). METHODS: Thirteen recreationally active (21.5 ± 2.5 years; 169.4 ± 9.4 cm; 69.6 ± 12.9 kg) females (n = 6) and males (n = 7) visited the laboratory on three separate visits. In a randomized order, participants completed three cycles of IPC at low (SHAM [20 mmHg]), moderate (80% of total arterial occlusion pressure), and high (220 mmHg) pressures. IPC was applied with a pneumatic cuff on the most proximal aspect of dominant limb. Each IPC cycle consisted of five minutes of pressure followed by five minutes of rest. Prior to and immediately following IPC, PPTThreshold and PPTTolerance were assessed from the rectus femoris muscle. Separate 3 (Pressure [low, moderate, and high) x 2 (Time [pretest, posttest]) repeated measures ANOVA were performed to assess any mean differences. RESULTS: There was no significant (p = 0.418) interaction or main effect for Pressure (p = 0.279) or Time (p = 0.389) for PPTThreshold. For PPTTolerance, there was no significant (p = 0.360) interaction or main effect for Pressure (p = 0.713) or Time (p = 0.105). CONCLUSIONS: Perceptions of pain were not affected by IPC regardless of pressure applied. These findings suggest that three cycles of IPC were not sufficient to induce a hypoalgesic effect. Additional IPC cycles or longer durations may be required to alter perceptions of pain.