Effectiveness of acupuncture combined with rehabilitation training vs. rehabilitation training alone for post-stroke shoulder pain: A systematic review and meta-analysis of randomized controlled trials

Shoulder pain after stroke is a fairly common complication that can significantly affect the quality of life of patients in recovery. This condition, known as post-stroke shoulder pain, is characterized by pain on the body side affected by paralysis and typically appears between two and three months after the stroke. Studies indicate that this complication can affect approximately 30% of patients who have had a stroke, being more frequent in the chronic phase of recovery. Shoulder pain not only causes physical discomfort but can also limit patients' participation in rehabilitation programs, prolong hospitalization, and contribute to depressive conditions and sleep disturbances.

The negative impact of this condition represents a major challenge for both patients and health systems, creating an urgent need for effective treatments.

This study aimed to evaluate the efficacy and safety of combining acupuncture with rehabilitation training compared with rehabilitation training alone for the treatment of shoulder pain after stroke. To do so, the researchers conducted a systematic review and meta-analysis, which is a type of study that pools and statistically analyzes the results of multiple previously published studies on the same topic. The research team conducted comprehensive searches in six scientific databases, including PubMed and Cochrane Library, from inception through February 2022. Only randomized controlled trials were included, which are considered the gold standard for evaluating the efficacy of medical treatments.

To be included in the analysis, each study had to directly compare acupuncture combined with rehabilitation versus rehabilitation alone in patients with shoulder pain after stroke. The researchers evaluated different outcomes, the primary one being the reduction of shoulder pain, measured using standardized scales. As secondary outcomes, upper-limb motor function, activities of daily living, shoulder range of motion, and possible adverse effects of the treatments were analyzed.

The analysis included 40 studies in the qualitative review and 35 studies in the meta-analysis, totaling 2,554 patients. The results demonstrated that the combination of acupuncture with rehabilitation was superior to rehabilitation training alone across all evaluated aspects. For shoulder pain, which was the primary outcome, the analysis of 31 studies with 2,290 patients showed a significantly greater pain reduction in the group that received combined acupuncture. In upper-limb motor function, evaluated through the Fugl-Meyer scale, 29 studies with 2,033 patients demonstrated superior improvement in the combined therapy group.

Activities of daily living, measured by the Barthel Index, also showed more pronounced improvement when acupuncture was added to rehabilitation treatment, as demonstrated in 12 studies with 906 patients. Shoulder range of motion showed significant improvements in all movements evaluated — internal rotation, posterior extension, anterior flexion, external rotation, and abduction — consistently favoring the combined therapy group. A subgroup analysis revealed that different types of acupuncture, including electroacupuncture, traditional acupuncture, and balance acupuncture, all demonstrated superior efficacy when combined with rehabilitation.

For patients suffering from shoulder pain after stroke, these results offer encouraging evidence that acupuncture can be a valuable complement to conventional rehabilitation treatment. The combined therapy not only provides greater pain relief but also improves the function of the affected arm, facilitating daily activities such as dressing, eating, and performing household tasks. The improvement in shoulder range of motion is particularly important, as it allows for greater functional independence and may prevent complications such as joint stiffness and muscle atrophy. For health professionals, these findings suggest that incorporating acupuncture into rehabilitation programs may optimize treatment outcomes.

Acupuncture proved to be a safe intervention, with only one study reporting an absence of adverse effects and the others not mentioning significant complications. This is especially relevant considering that many pain medications can have limiting side effects in patients who already face multiple health challenges after a stroke.

Despite the promising results, the study presents some important limitations that should be considered when interpreting the findings. The methodological quality of the included studies was variable, with only 35% classified as moderate to high quality. Many studies had deficiencies in the description of randomization methods, blinding of assessors, and concealment of participant allocation, which may introduce bias into the results. In addition, high heterogeneity was observed between studies — that is, there were considerable differences in the acupuncture protocols used, including selected points, manipulation techniques, treatment duration, and frequency of sessions.

Virtually all studies were conducted in China and published in Chinese, which may limit the generalizability of the results to other populations. The lack of standardization in acupuncture techniques also represents a limitation, as it makes it difficult to determine which specific approach would be most effective.

In conclusion, this systematic review and meta-analysis provides substantial evidence that acupuncture combined with rehabilitation training is more effective than rehabilitation alone for the treatment of shoulder pain after stroke, promoting not only greater pain relief but also significant functional improvements. However, due to the methodological limitations identified and the heterogeneity between studies, these results should be interpreted with caution. There is a clear need for more rigorous and standardized clinical trials in the future, including studies with better methodological quality, more uniform acupuncture protocols, and more diverse populations. For patients and professionals interested in this therapeutic approach, it is important to individually discuss the potential benefits and limitations, considering the specific characteristics of each case and the availability of qualified professionals in acupuncture and neurological rehabilitation.