and Orthopedic, Hubei University of Chinese Medicine, No.1 acceptance of acupuncture in patients with chronic low back pain: results of a prospective, randomized, controlled trial. J Altern Complement Med. 2013;19(12):935–41. 9. Lim TK, Ma Y,: http://dx.doi.org/10.1590/S1980-220X2018009003418 2 www.ee.usp.br/reeusp Effects of auricular acupuncture on chronic pain in people with back musculoskeletal disorders: a randomized clinical trial Rev Esc Enferm USP · 2019;53:e03418 INTRODUCTION Back pain, especially in the cervical and lumbar regions, is a common condition in people of different ages and may lead to years of disability(1). Among its causes, those associated with poor posture, a sedentary lifestyle, and age-related degenerative pathologies stand out(2). This type of pain usually occurs in sporadic episodes and heals after one to four weeks, but in some cases the pain remains for over three months, which characterizes the condition as chronic(3). Auricular acupuncture (AA) is a therapeutic resource that has been used for approximately 2,500 years to treat many clinical conditions(4), including chronic back pain, mainly in the lumbar region(5). According to the traditional Chinese medicine, stimuli in the ear activates energy channels called meridians over the body to restore and increase the circulating flow of Qi (vital energy) and Xue (blood)(6) and, consequently, promote pain relief. The Western clinical approach advocates that the action mechanisms of AA are related to the neuroendocrine, immune, and autonomic nervous systems(4), which jointly contribute to minimizing or eliminating pain. However, because of the significant heterogeneity in clinical protocols and methodological flaws in the studies, such as those observed in randomization, blinding, and determination of sample size processes, current evidence on the use of AA to treat chronic pain remains limited(7). No consistent evidence describing the effects of AA in all back regions is currently available. Given this panorama, the objective of the present study was to evaluate the effects of Chinese AA on the intensity of chronic pain, the relief caused by the intervention, the impact of pain on daily activities, and the pain threshold in people with back musculoskeletal disorders. METHOD Study type A parallel and blind randomized clinical trial was carried out between June 2015 and March 2016 in a public university in the state of Minas Gerais, Brazil. The examined population was 535 people who waited for treatment in the physical therapy clinic of the institution. Sample selection criteria The screening criterion was the presence of back pain, so 149 people were initially excluded. The following inclusion criteria were considered for the remaining participants: age group from 18 to 80 years; presence of chronic back pain for at least three months, of any origin, with an intensity equal to or higher than 4 in the Numerical Rating Scale(8); and schedule availability to attend the AA sessions. Exclusion criteria were: presenting an infection, inflammation, or wound in the ear; having allergy to the metal or micropore tape used in the sessions; having undergone a previous energy therapy any time in the three months which preceded the intervention; being under any physical therapy treatment or taking continuous medication for pain relief; refusing to receive auricular treatment with needles; and being pregnant. Additionally, intervention discontinuity criteria were applied: being hospitalized, missing two consecutive sessions, and not attending the clinic on the days scheduled for the evaluations. Intervention and data collection The AA treatment was carried out with sterilized and disposable semi-permanent auricular needles (Complementar Agulhas®), with 0.20 x 1.5 millimeters. The antisepsis of the ear was executed previously with cotton balls and a 70% ethyl alcohol solution. Acupoints were located with an Acu-Treat (DongBang®) localization device and the needles were inserted and attached with micropore. To define the best treatment therapy plan, an AA intervention protocol was developed based on the recommendations of the Standards for Reporting Interventions in Clinical Trials of Acupuncture(9). The protocol informed the style of acupuncture (traditional Chinese medicine); details of needling (number of needles, names or location of points used – if uni or bilateral, depth of insertion, needle stimulation, needle retention time, and needle type, including diameter, length, and manufacturer or material); treatment regimen (number, frequency, and duration of sessions); setting and context of treatment, including instructions to practitioners, and information and explanations to patients; practitioner background; and a precise description of the control or comparator (placebo). The protocol was submitted to an evaluation process by five acupuncturists with more than ten years of experience in the area. The auricular points of the treatment group were defined based on the energy balance according to the standards of traditional Chinese medicine and applied in the following order: Shenmen (TF4); kidney (CO10); sympathetic nervous system (AH6a); points of restoration of the energy balance, corresponding to an organ and a viscus; and cervical vertebrae (AH13), thoracic vertebrae (AH11), and/or lumbosacral vertebrae (AH9)(10). The placebo