Effect Of Blood Flow Restriction Training On Patient-reported Outcomes In Female Runners With Patellofemoral Pain

Patellofemoral pain (PFP) is the leading cause of lower extremity injury in female runners, with pain and symptoms significantly limiting running ability. Blood flow restriction training (BFRT) is an alternative training method that has been shown to be effective for reducing pain and improving function; however, there is uncertainty regarding the use of BFRT and its effects on patient-reported outcome measures in individuals with PFP. PURPOSE: To determine if low-load strength training with BFRT would lead to greater reductions of pain and greater ratings of self-reported knee function and running ability than low-load strength training without BFRT in female runners with PFP over a 10-week intervention period. METHODS: 20 female runners with PFP were randomly allocated into the BFRT group (n = 10; age: 31.2 ± 9.1 years; symptom duration: 26.3 ± 31.6 months) or standard of care (SOC) group (n = 10; age: 27.9 ± 7.5 years; symptom duration: 27.9 ± 43.9 months). Patient-reported outcome measures were collected at pre-intervention and post-intervention, and included the Knee Injury and Osteoarthritis Outcome Score Patellofemoral Pain Subscale (KOOS-PF) and University of Wisconsin Running Injury and Recovery Index (UWRI). Change scores were calculated as: post-intervention value - pre-intervention value. Independent t-tests were used to compare differences between groups and paired t-tests were used to compare differences within groups (α < 0.05). RESULTS: There were no significant differences between groups in change scores for KOOS-PF (BFRT: 27.1 ± 12.6; SOC: 24.3 ± 17.5; p = 0.69) and UWRI (BFRT: 9.0 ± 5.5; SOC: 11.7 ± 6.7; p = 0.34); however, both groups demonstrated significant improvements in the KOOS-PF (BFRT: 50.4%, p < 0.001; SOC: 44.9%, p < 0.01) and UWRI (BFRT: 53.9%, p < 0.01; SOC: 71.3%, p < 0.001) with all values exceeding their respective minimal clinically important difference. CONCLUSIONS: Low-load strength training with BFRT was not more effective than low-load strength training without BFRT for reducing pain and improving function and running ability in female runners with PFP. These findings indicate that low-load strength training with or without BFRT can be used to reduce pain and improve function in female runners with PFP.