Research Trends on Acupuncture for Shoulder Pain Treatment Over the Past 15 Years: A Bibliometric Analysis

Shoulder pain represents a significant and growing health problem in the global population, affecting between 7% and 30% of people, with higher prevalence in women and increasing with age. This type of pain, frequently caused by muscle strain, external impacts, and wear of the joint capsule, is considered the third most common musculoskeletal disorder, with a prevalence of 42%. In addition to physical discomfort, shoulder pain causes considerable emotional impact and significantly compromises patients' quality of life.

Conventional treatments for shoulder pain include oral anti-inflammatory medications, physical therapy, therapeutic exercise, drug injections, and surgery. However, research demonstrates that surgical interventions do not necessarily produce results superior to exercise or physical therapy, while prolonged use of hormonal medications can cause harmful side effects in patients. In this context, acupuncture has emerged as a promising therapeutic alternative, offering not only short-term pain relief but also addressing some underlying causes of pain in the long term. The technique offers advantages such as low risk, few side effects, ease of application, and low cost, making it widely accepted in clinical practice as a complementary and alternative therapy.

This study aimed to analyze research trends on acupuncture for the treatment of shoulder pain over the past 15 years, using bibliometric methods to understand the current state of research, identify areas of interest, and predict future directions. Researchers performed a systematic search in the Web of Science database, collecting articles published between 2008 and 2022 that addressed acupuncture and shoulder pain. After applying rigorous inclusion and exclusion criteria, they selected 135 articles for detailed analysis. Using specialized software such as VOSviewer and CiteSpace, the authors examined multiple dimensions of the scientific literature, including temporal distribution of publications, countries of origin, research institutions, principal authors, scientific journals, frequent keywords, and emerging trends in the field.

The analysis revealed an overall growth in the number of publications on acupuncture for shoulder pain over the 15 years studied, indicating growing interest and acceptance of the technique by researchers, clinicians, and patients. In terms of geographic distribution, China leads in absolute number of publications with 45 articles, followed by the United States with 28 articles. However, the United States shows higher centrality in the scientific collaboration network, suggesting greater influence and impact of its research. Among institutions, Kyung Hee University in South Korea stands out with 18 publications, demonstrating leadership in the area.

The most prolific authors include renowned researchers such as Vickers Andrew J., Lewith George, and MacPherson Hugh, who have contributed significantly to establishing the scientific basis of acupuncture in pain treatment. The journal "Pain" emerged as the principal venue for publication of research in the area, both in number of articles and in citations, consolidating itself as a central reference in the field.

The clinical implications of this study are substantial for patients and health care professionals. For patients with shoulder pain, the results offer growing scientific evidence that acupuncture represents a legitimate and effective therapeutic option, especially considering the potential adverse effects of conventional treatments. The technique can be particularly valuable for patients seeking alternatives to medications or who have experienced unsatisfactory results with traditional therapies. For health care professionals, the study provides guidance on the evolution of research in acupuncture, highlighting the importance of rigorous research protocols and standardized assessment methods.

The analysis of emerging keywords, such as "protocol," "systematic review," and "stimulation," indicates promising future directions, including studies on the neurobiological mechanisms of acupuncture and its application in specific conditions such as post-stroke pain. The data also suggest that acupuncture is increasingly being integrated into multidisciplinary approaches to pain management, reinforcing its legitimacy in the modern therapeutic arsenal.

The study presents some important limitations that should be considered when interpreting the results. First, the search was restricted to the Web of Science database, potentially excluding relevant research published in other scientific databases. Second, the analysis included only English-language literature, which may underestimate significant contributions from countries where acupuncture has a more established tradition, especially in Asia. This linguistic limitation may have resulted in inadequate representation of research conducted in Chinese, Japanese, and other Asian languages, where acupuncture has deep historical roots.

Additionally, although China has the largest number of publications, its relatively low centrality in the collaboration network suggests that much research may be conducted in isolation, without broad international collaboration, potentially limiting the impact and dissemination of findings.

Considering these limitations and the study's findings, important directions emerge for the future of research on acupuncture for shoulder pain. It is essential that researchers establish more robust collaborations among different countries and institutions to maximize the quality and impact of research. The development of more rigorous and standardized research protocols will be essential to advance understanding of the mechanisms of action of acupuncture and to establish more precise clinical guidelines. The growing emphasis on systematic reviews and meta-analyses represents a positive evolution but requires special care in selecting high-quality studies and applying appropriate methodologies.

Finally, the bibliometric study demonstrates that acupuncture for shoulder pain is consolidating itself as a legitimate and expanding research area, offering hope for millions of patients seeking effective and safe alternatives for the management of their chronic pain.