Effects of Neurostimulation With Blood Flow Restriction on Physical and Mental Health–Related Quality of Life in Military Personnel With Patellofemoral Pain Syndrome: Secondary Data Analysis

BACKGROUND: Musculoskeletal injuries such as patellofemoral pain syndrome (PFPS) result in loss of readiness in military warfighters, underscoring the importance of therapies to accelerate recovery for rapid return-to-duty. Non-pharmacologic interventions, including exercise, neuromuscular electrical stimulation (NMES), and blood flow restriction (BFR), may be beneficial in garrison and far-forward settings. However, since the electrical currents used in NMES and the restriction of blood flow during NMES and BFR therapies cause pain and discomfort that may be intensified when combined, there is concern that these therapies could lead to heightened physical and psychological difficulties. Thus, the present secondary analysis examined whether the combined use of BFR, NMES, and exercise affected pain intensity, functional abilities, and the physical (PCS) and mental (MCS) components summary scores of the Health-Related Quality of Life (HRQoL) questionnaire. MATERIALS AND METHODS: This randomized controlled trial entailed the random assignment of 84 service members with PFPS to 1 of 2 groups: sham with application of 20 mmHg pressure or BFR pressure to 80% occlusion. BFR-NMES was performed in clinic 2 times per week, while NMES with exercise and exercise alone were performed at home on alternating days and omitted on in-clinic days. The outcome measures included the 12-item Short Form Health Survey v.2 (SF-12v2) MCS and PCS scales. Pain levels were measured using the Anterior Knee Pain Scale (AKPS) and Visual Analog Scale (VAS). RESULTS: Over the 9-week intervention, both groups demonstrated similar improvements in pain as measured by the AKPS and VAS scales. Both groups also showed similar improvements on the SF-12v2 PCS, progressing from well below normal to almost normal over the 9 weeks. However, a significant difference in the MCS scores between the 2 groups was observed over time, as evidenced by a notable group-by-time interaction (P = .01). At baseline, both groups scored above the average "normal" score of 50 (SD = 10) on the MCS. By week 9, the MCS score for the sham BFR group remained essentially unchanged, while that of the high BFR group declined below average. CONCLUSIONS: Mental health is as important as physical health in optimizing the recovery of injured military warfighters. The balanced use of non-pharmacologic interventions such as exercise, NMES, and BFR therapy is essential for promoting mental and physical readiness. The observed decline in mental scores over time highlights the potential need for integrating pain management techniques, behavioral strategies, and social support into future rehabilitation protocols to enhance overall outcomes. By addressing these elements comprehensively, military warfighters can develop the resilience required for a successful return-to-duty in both resource-rich clinical settings and demanding far-forward environments. CLINICAL TRIAL REGISTRATION: The Blood Flow Restriction trial was registered in ClinicalTrials.gov (Identifier: NCT04086615), first posted on September 11, 2019.