The Impact of Fu's Subcutaneous Needling on Lower Limb Muscle Stiffness in Knee Osteoarthritis Patients: Study Protocol for a Pilot Randomized Controlled Trial.

Background: Knee osteoarthritis (OA) is a leading cause of disability worldwide, with clinicians often observing increased muscle stiffness associated with joint pain and dysfunction. This study examines the impact of Fu's Subcutaneous Needling (FSN), a non-pharmacological technique, on muscle stiffness in the lower limbs of individuals with knee OA.

Materials and methods: This study protocol is a pilot, single-center, randomized controlled trial. Sixty knee OA patients will be allocated equally for FSN or electroacupuncture (EA) treatments. Interventions will be applied thrice weekly for the first two weeks and twice weekly for the subsequent two weeks for a total of ten sessions. Assessments will be conducted at baseline, post-initial session, after four weeks of intervention, and at the end of a four-week follow-up. The primary outcome will be the muscle stiffness in the lower extremities, as measured by shear wave elastography (SWE). Secondary outcomes include response rate, a reduction in the mean pain intensity on the Numerical Rating Scale (NRS) by at least two points and on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function subscale by six points at week four compared with baseline. Weekly monitoring of the NRS and WOMAC scores will determine the rapidity of pain alleviation and functional improvement, along with 12-item short-form (SF-12) score changes from baseline to week four.

Results: This is the first standardized protocol examining the effects of FSN on lower limb muscle stiffness in patients with knee OA by SWE. We hypothesize that FSN could outperform EA in alleviating lower limb stiffness associated with knee OA. Findings will contribute to the body of knowledge regarding the efficacy of acupuncture-derived interventions in managing muscle stiffness and may guide future research directions.

Study registration: The trial has been registered on the Chinese Clinical Trial Registry (Registered number: ChiCTR2300073615). Registered 17 July 2023.