Randomisation and Blinding

Participants are randomized equally to active or sham stimulation. No independent Data Monitoring Committee is used because the intervention is considered low risk, non-pharmacological, and short-term with no planned interim analysis. Participants are randomised into 10 equal groups using blocked randomisation in SPSS by an independent statistician, with a separate administrator managing the allocation sequence to preserve concealment. Outcome assessors and statisticians are blinded to group assignment, and unblinding occurs only when required for participant safety. Allocation is concealed with consecutively numbered sealed opaque envelopes. Patients wear a sleep mask during injections so they cannot see the medication. The physiotherapist administering treatment is blinded by a double-blind stimulator mode and session-specific codes. Outcome assessment is protected by REDCap self-reporting and blinded assessors for neurophysiological and neuromuscular outcomes. Acupuncturists cannot be blinded due to the nature of the treatment, making the trial single-blind from the provider perspective. Multiple births are allocated to the same arm to reduce unblinding or dosing-error risks. T…