Exercise‐induced hypoalgesia with end‐stage knee osteoarthritis during different blood flow restriction levels: Sham‐controlled crossover study
Daniel C. Ogrezeanu, Laura López, Enrique Sanchís‐Sánchez, Luis Suso‐Martí, Rubén López‐Bueno, Rodrigo Núñez‐Cortés, Carlos Cruz‐Montecinos, Sofía Pérez‐Alenda, José Casaña, Pedro Gargallo, Joaquín Calatayud
Abstract
BACKGROUND: Blood flow restriction (BFR) training could be a valuable treatment to induce exercise-induced hypoalgesia (EIH) in patients with end-stage knee osteoarthritis. However, the use of BFR in these patients is poorly explored and there is no evidence about the training dosage needed. OBJECTIVE: To evaluate the effect of resistance training protocols with different occlusion levels of blood flow restriction (BFR) on EIH in patients with end-stage knee osteoarthritis. DESIGN: Crossover study. SETTING: University physical exercise laboratory. PARTICIPANTS: 26 adults with end-stage knee osteoarthritis. INTERVENTIONS: Patients performed four sets (30, 15, 15, and 15 repetitions) separated by 1-minute rests of three protocols/sessions of low-load (30% one-repetition-maximum) seated knee extensions with elastic bands and BFR: placebo (sham BFR), BFR at 40% arterial occlusion pressure (AOP) and BFR at 80% AOP. MAIN OUTCOME MEASURES: Pressure Pain Thresholds (PPT) and Visual Analog Scale (VAS) collected before, immediately after session, and after 10 minutes. RESULTS: No differences in EIH were found between the different levels of BFR. However, 80% AOP protocol worsened VAS scores immediately (mean difference [MD]: -21.2 (95% confidence interval [CI] -33.9 to -8.5) while improving PPT immediately (MD affected limb: -.6 [95% CI -1.1 to -.2]); contralateral: -.6 (95% CI -1.0 to -.2]) and at 10 minutes (MD affected limb: -.6 [95% CI) -1.2 to -.1]; contralateral: -.7 [95% CI -1.1 to -.2]; and forearm: -.5 [95% CI -.9 to -.05]) post-exercise compared to baseline. CONCLUSIONS: There is no EIH difference after using different occlusion levels. EIH is modulated by pain-related psychological constructs and self-perceived health status.