"Comparing Blood Flow Restriction Devices: How They Measure Limb Pressure"

Our objective is to compare limb occlusion pressure (LoP) measurements obtained using different devices in recreationally active individuals. This study employs a crossover design, with 21 participants undergoing LoP assessments in both supine and standing positions using each of the following five devices: ZIMMER Tourniquet System – a medical-grade pneumatic device commonly used in surgical and clinical settings for controlled occlusion. SUJI BFR Cuff – a semi-automated blood flow restriction system that connects to a smartphone app for guided occlusion pressure application. AIRBANDs – manually inflated cuffs with a handheld pump and integrated pressure gauge, typically used in fitness environments. SMART Cuffs Pro – an automated BFR system that determines LoP via pulse detection technology. Pulse oximeter paired with a standard blood pressure cuff – a traditional method used to estimate LoP based on the disappearance of pulse signal, serving as a reference technique. Participant anthropometrics including height, weight, and leg dominance will be recorded prior to testing. All device applications will be performed by a certified exercise physiologist to ensure consistency and safety. For each device, participants will undergo two trials: one trial to determine LoP in the supine position and one trial to determine LoP in the standing position. No exercise protocols will be performed during these trials; the trials will only involve inflation of the cuff to determine LoP. The time to determine LoP will vary between devices, typically ranging from 20 seconds to 2 minutes. Devices will be applied in a randomized order, and two trials will be conducted per device on the dominant leg, with a 5-minute rest (washout) period between trials to allow for full vascular recovery and eliminate carryover effects. A brief familiarization session with each device will be provided before formal testing. After each LoP trial, participants will rate their perceived discomfort using a standard 0–10 numerical scale. All testing will be conducted in a single session lasting approximately 120 to 150 minutes per participant. This crossover protocol, incorporating randomization and washout periods, is designed to ensure the internal validity of comparisons across devices.