Efficacy of soothing cream gel in the range of motion and chronic pain at the shoulder and elbow: protocol of a double-blinded, randomised, placebo-controlled trial

Introduction Upper limb problems have a significant impact on the global population leading to pain and restricted joint mobility, ultimately impacting their quality of life. Traditional treatments, such as non-steroidal anti-inflammatory drugs and corticosteroids, often come with undesirable side effects, prompting patients to seek alternative therapies. In this trial, we hypothesise that soothing cream gel (SCG) will improve range of motion and chronic pain in the shoulder and elbow. The objective of this trial is to evaluate the efficacy of SCG in improving the range of motion and chronic pain in the shoulder and elbow. Methods and analysis A double-blinded, randomised, placebo-controlled trial is conducted to compare the effects of SCG and placebo gel. SCG contains Vitis vinifera essence, Melaleuca viridiflora essential oil, etc, and is manufactured according to Good Manufacturing Practice standards. The placebo gel will be processed with similar appearance, texture and scent but will lack active ingredients. 70 participants with upper limb problems will be recruited from four study sites, including clinical centres and a sport department at the Chinese University of Hong Kong (CUHK). Participants will be randomly assigned to either treatment group or placebo group for 2 weeks. Primary outcome will be the range of motion in the upper limb, assessed by a goniometer, to measure active flexion and abduction for the shoulder, and active flexion and extension for the elbow. The primary efficacy analyses will be based on the full analysis set following the intention-to-treat principle. Ethics and dissemination The trial has obtained approval from the joint CUHK-New Territories East Cluster (CRE-2023.142), and the patient enrolment commenced in July 2023. Written informed consent will be obtained from all participants prior to participation. Study results will be disseminated through publication in peer-reviewed journals and presentations at conference.