Effects of Sanqi Shengyu External Application Cream and Pulsed Electromagnetic Field on Knee Osteoarthritis in Older Adults: A Randomized Controlled Trial

ABSTRACT Background and Purpose Knee osteoarthritis (KOA) is a leading cause of disability worldwide, necessitating safe and effective therapies. This study aimed to compare the efficacy of the Sanqi Shengyu External Application Cream, an external Chinese herbal therapy (ECHT), pulsed electromagnetic field (PEMF), and their combination in alleviating pain and improving function in KOA patients. Methods This single‐blinded, multi‐center randomized controlled trial enrolled 120 elderly participants with KOA (Kellgren‐Lawrence grade ≥ 2). Participants were randomly allocated to one of the four groups: (1) ECHT + PEMF + exercise, (2) ECHT + exercise, (3) PEMF + exercise, or (4) exercise + health education (control). Interventions were administered 5 days/week for 4 weeks. Primary outcomes included pain (visual analog scale, VAS) and function (The Western Ontario and McMaster Universities Osteoarthritis Index, WOMAC), assessed at baseline, post‐intervention, and 4‐week follow‐up. Secondary outcomes encompassed muscle strength and knee range of motion (ROM). Results All groups showed significant time effects for pain and function (VAS, F  = 122.9, p  < 0.001; WOMAC, F  = 103.7, p  < 0.001). The combined therapy group demonstrated superior outcomes (reduced VAS by 3.0 points, p  < 0.001), with sustained reductions in VAS (2.8 vs. baseline 5.8) and WOMAC (14.2 vs. baseline 24.8) at follow‐up ( p  < 0.001). ECHT alone exhibited durable efficacy, while PEMF's benefits diminished post‐intervention. The control group showed significant but less pronounced improvements than the active intervention groups. Muscle strength improved modestly in the combined group, but no significant ROM changes were observed. Discussion The Sanqi Shengyu External Application Cream can alleviate KOA symptoms with sustained effects in older adults, outperforming PEMF alone. Combining ECHT and PEMF yields synergistic benefits, suggesting a novel multimodal approach for KOA management. Future research should explore long‐term efficacy and mechanisms of action. Trial Registration Chinese Clinical Trial Registry Platform: www.chictr.org.cn (No. ChiCTR2400087644)