The purpose of this study was to investigate the blood flow/pressure relationship (linear or nonlinear) in the superficial femoral artery when seated, as well as to investigate blood flow changes with exercise using varying cuff pressures and a preexercise (PE) condition. The presence of venous outflow with occlusion at rest and exercise was also investigated. Methods: Twenty-three subjects visited the lab on 3 occasions. First to determine linearity of blood flow using 0% to 90% arterial occlusion pressure (AOP), and venous outflow at rest and during exercise with cuff inflated to 40% AOP. Subsequent visits compared blood flow between rest and PE conditions to determine average blood flow, heart rate, systolic and diastolic blood pressure changes in response to a blood flow-restricted (BFR) exercise protocol. Results: Blood flow/pressure relationship is nonlinear at the superficial femoral artery (p < 0.01). No significant differences in average blood flow, conductance or mean arterial pressure (MAP) were found between 30% to 80% AOP (p = 1.0 to .08). Blood flow is not significantly different between rest and PE groups (p = 0.49) although initial 40% AOP and 40% exercise arterial occlusion pressure (EAOP) values were different between rest and PE groups. (p < 0.01). Conclusion: The nonlinear relationship at the superficial femoral artery demonstrates higher cuff pressures are not necessary to reduce blood flow in BFR exercise of the lower extremity. Furthermore, PE or warm-up is not necessary prior to determining EAOP as it does not alter blood flow responses during BFR exercise. We found evidence of venous outflow above the cuff both at rest and during exercise at 40% AOP.

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Previously established research has shown that whole body vibration (WBV) is effective at increasing intramuscular temperature (IMT) of the medial gastrocnemius (MG) at 26Hz. A “reaction” of itching and redness to WBV has been noted in prior research, but is not reported in all subjects. The purpose of this study was to determine if WBV affects skin and MG IMT differently in those exhibiting this reaction vs those with no reaction when performing a standard static semi‐squat WBV protocol. 60 subjects were screened, 10 exhibited a reaction; 6 had no reaction. Subjects completed two 5x60s bouts of WBV (26Hz, 4mm amplitude) on an oscillating platform with 15s rest between bouts. Skin and IMT were taken pre, mid (after 5 min vibration), and post 10 min of vibration. There was no difference in starting temperatures for skin or MG IMT. No significant change in skin or MG IMT of the non‐reactive group. Reactive group had significant increases in skin temperature (pre‐mid p<.0001, 2.32°C; pre‐post p<.0001, 2.57°C) and MG IMT (pre‐mid p<.0001, 1.5°C, mid‐post p<.004, 0.95°C, pre‐post p<.0001, 2.46°C). In conclusion, WBV exerts its effects upon reactive and non‐reactive groups differently. This difference could be due to histamine release due to WBV. Future research should be conducted to determine how WBV affects skin and muscle temperature or blood flow response. Grant Funding Source: None

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