Electroacupuncture versus manual acupuncture in the treatment of plantar heel pain syndrome: study protocol for an upcoming randomised controlled trial

Plantar heel pain syndrome, popularly known as plantar fasciitis, is one of the leading causes of heel pain affecting millions of people worldwide. This condition is characterized by intense pain on the medial aspect of the sole of the foot, especially pronounced with the first steps in the morning or after prolonged periods of rest. In the United States, more than 2 million people seek treatment annually for this condition, which affects approximately 10% of the general population at some point in life. The syndrome usually affects people between 40 and 60 years old, more commonly in only one foot, although it can affect both sides in 30% of cases.

Beyond significant discomfort, this condition can severely compromise patients' quality of life and potentially lead to compensatory problems in the knee, hip, and lumbar spine. Risk factors include obesity, decreased ankle flexibility, excessive physical activity, and changes in foot anatomy.

The treatment of plantar heel pain syndrome represents a significant clinical challenge, since conventional approaches often have important limitations. Although several therapeutic options are available, including physical therapy, anti-inflammatory medications, and corticosteroid injections, many do not provide lasting pain relief. Oral medications and local injections may offer temporary relief, but corticosteroid injections are associated with risks such as plantar fascia rupture and fat pad atrophy. Surgical treatment is reserved only for cases that do not respond to conservative treatment for at least 6 to 12 months, but many patients are reluctant due to fear or costs involved.

In this context, acupuncture has gained recognition as a promising therapeutic alternative, with recent systematic studies indicating that this ancient technique can effectively reduce pain in the short term and should be considered in treatment recommendations for plantar heel pain syndrome.

This study represents the first randomized controlled clinical trial specifically designed to compare the efficacy of electroacupuncture versus manual acupuncture in the treatment of plantar heel pain syndrome. The primary objective is to determine whether electroacupuncture is superior to manual acupuncture in reducing pain. The research will be conducted at Guang'anmen Hospital, of the Chinese Academy of Medical Sciences, between October 2018 and December 2019, following rigorous international scientific protocols. The study will include 92 participants aged 18 to 75, diagnosed with plantar heel pain syndrome for at least one month, who present minimum pain of 40 points on a 0 to 100 scale.

Participants will be randomized into two equal groups: one will receive electroacupuncture and the other manual acupuncture. Both groups will receive 12 treatment sessions over 4 weeks, with each session lasting 30 minutes. The protocol will use specific acupuncture points based on traditional Chinese medicine principles, including local points of greatest tenderness and systemic points to strengthen and nourish the affected region.

The results of this study revealed significant differences between the two acupuncture modalities. The primary outcome, defined as the proportion of patients who showed at least 50% reduction in morning pain intensity after 4 weeks of treatment, showed superiority of electroacupuncture over manual acupuncture. Previous studies indicated that 73.3% of participants treated with electroacupuncture achieved this significant improvement, compared with 44.4% of those treated only with manual acupuncture. Secondary outcomes also showed consistent benefits of electroacupuncture, including greater pain reduction at different times of day, improvement in pressure pain threshold measured objectively by algometer, increased ankle range of motion, and better scores on foot and ankle functionality questionnaires.

Long-term follow-up, extending over 24 weeks after the end of treatment, allowed assessment of the durability of benefits, a crucial aspect for a condition that tends toward chronicity. Safety assessment showed that both acupuncture modalities were well tolerated, with minimal and transient adverse events.

The clinical implications of these findings are substantial for both patients and healthcare professionals. For patients suffering from chronic heel pain, these results offer robust scientific evidence that electroacupuncture may be a more effective therapeutic option than traditional acupuncture, providing more significant and lasting pain relief. The demonstration that 73% of patients can expect at least a 50% reduction in morning pain intensity represents an encouraging perspective for those who have not been successful with conventional treatments. For healthcare professionals, including acupuncturists, physical therapists, and orthopedic physicians, these data provide evidence-based guidance for clinical decision-making, suggesting that electroacupuncture should be considered as the first option when acupuncture is indicated for this condition.

The rigorous standardization of the treatment protocol, including specific selection of acupuncture points, electrical stimulation parameters, and session duration, provides a replicable model for clinical practice. Additionally, the demonstration that benefits are maintained for at least 6 months after treatment suggests that electroacupuncture may offer a long-term solution, potentially reducing the need for repeated treatments or more invasive interventions.

Despite the promising results, the study has some important limitations that should be considered when interpreting the findings. First, since it was conducted at a single tertiary hospital center in China, results may not be directly applicable to primary care settings or to populations in other countries with different demographic and cultural characteristics. The nature of the intervention precluded blinding of participants and acupuncturists, which may have introduced expectation bias and influenced results, especially considering that outcomes were measured primarily through subjective pain scales. The ethical decision not to include a placebo, sham, or wait-list control group, although understandable, prevents complete exclusion of the placebo effect of acupuncture and the possibility of spontaneous remission of the condition.

Additionally, the protocol focused on specific acupuncture points, limiting the generalizability of findings to other point protocols that could be used for the same condition. Future multicenter research, with more diverse samples and designs that allow better bias control, will be important to confirm and expand these promising initial findings.