Efficacy of acupuncture in treating chronic non-specific low back pain

Ming Guo, Joseph Cacciottolo, Li Yi (李艺), Charles Savona Ventura

1 Centre of Traditional Chinese Medicine and Culture, University of Malta, Msida MSD 2080, Malta

2 Faculty of Arts, University of Malta, Msida MSD 2080, Malta

3 School of Acupuncture-moxibustion and Tuina, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China

Abstract Objective: To provide an update on the evidence of the effectiveness of acupuncture in treating chronic non-specific low back pain (CNSLBP) based on randomized controlled trials (RCTs) of acupuncture for CNSLBP published between 2006 and 2020.

Keywords: Acupuncture Therapy; Low Back Pain; Randomized Controlled Trial; Review

Low back pain is a very common symptom and can be defined as a localized pain between the level of the 12th rib and the inferior gluteal folds in the presence or absence of referred leg pain. It can be classified as specific or non-specific low back pain (NSLBP)[1].

Specific low back pain refers to low back pain caused by such pathophysiological mechanisms as infection,tumor, osteoporosis, fracture, structural deformity,radicular syndrome and cauda equina syndrome[2]. It amounts for 10.0% of total low back pain cases[1]. On the other hand, NSLBP accounts for the remaining 90.0% of cases[1], refers to any back pain that does not have a specific pathological cause, meaning that it is a condition caused by a combination of mechanical, psychological and neurophysiological factors[3]. The current conservative treatment modalities used for treating low back pain in the Western countries include relative rest,a change in lifestyle, chiropractic manipulation,physiotherapy and the use of non-steroidal antiinflammatory drugs (NSAIDs) and other medications such as muscle relaxants, anti-depressants, and opioids[4].Anti-smoking programmes, as well as ergonomics and postural educations have also been proposed[5]. Due to the non-specific, multifactorial nature and the recurrent nature of NSLBP, there has been a lack of development of a standardized treatment regime[1]. This has led to the use of ineffective interventions which are probably the main reason for the social and economic burden that is associated with low back pain[2].

Traditional Chinese medicine (TCM) is a very ancient system of medicine that has existed for thousands of years[6]. Unlike Western medicine which is based on the anatomical and physiological changes of the human body[7], TCM is mostly said to be based on ancient Chinese philosophies, especially those of Daoism and Confucianism which observed the harmony and balance between nature and human beings, giving indications of how nature can affect humans[8]. A 2011 study aimed at exploring the possible causative factors for low back pain from a TCM viewpoint[9]. Their study concluded that low back pain can be caused by four factors, namely qi and/or blood stagnation, cold/dampness and warmth/heat (yin and yang imbalance), and kidney deficiency.Therefore, the aim of TCM treatment is to avoid qi and blood stagnation[9], to restore the harmony between yin and yang[10], and to reinforce the kidney since one of the main symptoms of deficiency of the kidney is low back pain[9].

However, based on the conclusions of clinical trials carried out prior to 2006, the European Guidelines for Management of Chronic Non-specific Low Back Pain did not accept Chinese acupuncture as a treatment intervention for chronic low back pain because of conflicting evidences[11]. This literature review study therefore aims to provide an update on the evidence of the effectiveness of acupuncture, based on randomized controlled trials (RCTs) published between 2006 and 2020. It also aims to identify the current evidence-based methods and approaches that are being used when it comes to treating chronic low back pain with Chinese acupuncture.

1 Method

A comprehensive literature search was conducted through the University of Malta website, using the HyDi search engine. The ‘Advanced Search’ option was chosen in order to search for articles that were published in English, and associated with the key words, ‘Chronic’,‘Acupuncture’, ‘Needle’, ‘Needling’, ‘Non-specific’ and ‘Low Back Pain’, which were entered in the ‘Subject’ field, from the year 2006 till 2020.

The studies chosen in this literature review had to be RCTs that were published between 2006 and 2020.Participants who were recruited for these studies had to be adults, diagnosed with NSLBP. The intervention applied had to be either manual acupuncture or electroacupuncture. Both techniques must involve inserting acupuncture needles into acupoints along a meridian or the Ashi point, which is defined as a painful point felt by a participant.

Any non-RCTs, case-studies and experts’ opinions were excluded from this literature review. Also, studies that recruited participants with known causes of low back pain such as pregnancy, sciatic pain, spinal fractures,malignancy, infections, and history of previous spinal surgeries were not included in this literature review.Lastly, studies that observed the effects of auricular acupuncture were also excluded.

In order to assess the quality of the chosen studies, the Jadad score was used. The Jadad score is a tool that is used to assess the quality of RCTs, especially in researches related to pain. It offers the best validity and reliability evidence, and focuses on three key aspects,namely randomization, blinding, and withdrawal or dropout. A score between 0 and 5 is used as a rating,with 0 score indicating low quality trial and 3 or above indicating high quality trials[12]. Furthermore, Standards for Reporting Intervention in Controlled Trials of Acupuncture (STRICTA) guideline and the Consolidated Standards of Reporting Trials (CONSORT) guideline were also used to observe the details involved in the chosen RCTs mentioned in this literature review study. According to a systematic review carried out in 2016[13], the quality of RCTs of acupuncture in China has improved ever since the introduction of the STRICTA and CONSORT guidelines.

2 Results

The HyDi search engine had identified 547 search results, out of which only 18 studies were relevant to this literature review[14-31]. The other search results were excluded mainly because they were either copies of these 18 studies, or else, did not meet the criteria of this study.

From the 18 studies, 15 studies scored high in quality on the Jadad score, and 3 scored low in quality. Nine out of the 18 RCTs compared the effectiveness of acupuncture with usual care; 6 out of 18 studies compared the effects of verum and sham acupuncture;and 2 out of the 18 studies compared the effect of individualized acupuncture versus standardized acupuncture. Furthermore, the frequently used acupoints, number of acupuncture sessions, frequency of acupuncture, and needling techniques were noted by following the STRICTA and CONSORT guidelines (Table 1).

3 Discussion

3.1 Acupuncture versus conservative treatment

The 9 RCTs[15-16,20,22-25,28-29]that compared the effectiveness of acupuncture versus current conservative treatment interventions concluded that acupuncture was significantly more effective with regards to pain and function. These results are in line with two more recent meta-analysis studies[32-33]and a very recent systematic review carried out in 2015[32], all of which concluded that acupuncture was superior over usual care and conventional therapies.

Table 1. Summary of studies

Table 1. Summary of studies (continued)

Table 1. Summary of studies (continued)

3.2 Acupuncture versus sham acupuncture

Out of the six studies that compared the effect of acupuncture versus sham acupuncture (superficial acupuncture), three German studies[34,17,20]concluded that there were no significant differences between acupuncture and sham acupuncture. However,acupuncture obtained significantly better results over usual care, both in the short term and in the long term[35].The other three studies[18-19,27]were in contrast to the three German studies. They all revealed that acupuncture obtained significantly better results than sham acupuncture in patients suffering from chronic low back pain. The main reason behind this contrast difference may be due to the possibility that sham acupuncture, which involved the use of superficial acupuncture, had a specific physiological effect in improving pain and function[23]. In fact, Brinkhaus B,et al[17]believed that this physiological effect may be of an analgesic nature which in turn helped to reduce low back pain through the activation of nociceptors.Furthermore, in a brain magnetic resonance imaging study[36], no difference in brain activity was found between superficial and deep needling, thus indicating their similarities which further suggest that superficial acupuncture may not be a suitable sham intervention.

3.3 Individualized versus standard acupuncture

Two studies that compared individualized acupuncture with standard acupuncture in this literature review, and they concluded that both individualized and standard acupuncture managed to significantly reduce chronic low back pain and improve function; however, no significant differences between them were found[23,26].Despite their findings, individualized acupuncture is preferred over standard acupuncture because the acupoints chosen and the number of acupuncture needles used should be based on individual diagnosis which tends to vary from one patient to another[37]. In fact, most of the studies used for this literature review study addressed individualized acupuncture.

3.4 Frequently used acupoints

In all 18 studies, acupoints were chosen from four meridians, namely the Bladder Meridian, the Gallbladder Meridian, the Governor Vessel, and the Kidney Meridian. Some commonly mentioned acupoints include Taixi (KI 3) and Shenshu (BL 23), Dachangshu(BL 25), Ciliao (BL 32) and Weizhong (BL 40), Huantiao(GB 30), Yanglingquan (GB 34), Yaoyangguan (GV 3) and Mingmen (GV 4).

保护的作用.漏电保护器的功能检测；为了经常检查漏电保护器的动作性能，漏电保护器装有实验按钮，在漏电保护器开关闭合后，按下实验按钮 SB，如果开关断开，则证明漏电保护器正常.一般一月应检查一次.

3.5 Number of acupuncture sessions

This literature review study also revealed that 12 out of the 18 studies applied ten to twelve sessions of acupuncture treatments for participants in the acupuncture groups. This number of sessions is in line with a study carried out by Berman BM,et al[38]who concluded that ten to twelve acupuncture sessions should be carried out over a period of 8 weeks in order to achieve significant relief of chronic low back pain. One particular 2017 study[30]compared the difference between four sessions, seven sessions and ten sessions,concluding that, although four sessions brought significant improvement, ten sessions obtained even greater significant improvement and patient satisfaction than the four-session group.

3.6 Frequency of acupuncture

Most of the studies examined in this literature review involved application of acupuncture either once per week or twice per week. There was only one study that specifically assessed the difference between lowfrequency acupuncture (twice per week) and highfrequency acupuncture (five times per week)[21].Although both frequencies were effective in reducing low back pain, there were no significant differences between them. The authors therefore concluded that twice per week acupuncture treatment may be sufficient to reduce low back pain.

3.7 Needling technique

One characteristic common to all the studies that mentioned needling technique is the achievement of the needling sensation or Deqi during treatment. Deqi is said to represent the flow of qi or energy along a meridian in the body. It is often described as a numb, heavy and dull sensation that is usually felt at the needling site during acupuncture manipulation[27]. Two common manipulations described in this literature review were the lifting and thrusting manipulation and the rotation or twirling manipulation. The studies in this literature review believed that the achievement of qi (Deqi) is important in bringing about therapeutic changes during treatment, and at the same time, it indicates accurate location of an acupoint[39]. Only one study examined the difference between manual acupuncture and electroacupuncture[31]. Although both types of acupuncture obtained improvements in NSLBP, there was no significant difference between the two methods.

4 Conclusion

The main limitation of this literature review study is that only trials that were published in English were included. Although many Chinese acupuncture studies have been carried out in China, the HyDi search engine failed to provide access to any of these studies, despite that the language option in the HyDi search engine was set to ‘any language’, hence providing limited access to Chinese studies. In fact, this led to the selection of only eighteen studies that could be included in this literature review. Despite of this, through the analysis and comparison of the studies selected for this literature review, acupuncture has been proven to be significantly more effective than current conservative treatment modalities in reducing the severity of chronic low back pain and in improving functional abilities.

Conflict of Interest

The authors declare that there is no potential conflict of interest in this article.

Acknowledgments

This study was supported by Programme of Center for International Development of Traditional Chinese Medicine, TCM International Cooperation Special Project,National Administration of Traditional Chinese Medicine(国家中医药管理局中医药国际合作专项中医药国际化发展研究中心项目, No. GZYYGJ2020003); University of Malta; and the Centre of Traditional Chinese Medicine and Culture, University of Malta.

Author’s contribution

Ming Guo wrote the manuscript and provided the data in Table 1. Joseph Cacciottolo revised the manuscript. Li Yi and Charles Savona Ventura provided guidance and liaised between editor and authors. All authors reviewed the final manuscript.

Received: 4 September 2020/Accepted: 26 November 2020