Restless legs syndrome (RLS) is defined by the International Classification of Sleep Disorders as “causing a desire to move the lower extremities with unpleasant senses that appear before sleep [1].” The International RLS Study Group (IRLSSG) stated the following four diagnostic conditions for RLS, which was published in 1995 [2]: (1) the legs feel uncomfortable with an unpleasant sensation and patients feel the urge to move the legs; (2) the symptoms appear or worsen when staying still in one position; (3) walking or moving the legs relieves the symptoms; and (4) symptoms only appear or worsen at night. RLS has been reported to have a prevalence of “7.2%” to “11.5%” in Europe and the United States. In an epidemiological survey conducted in Korea, it was indicated that 7.5% of the participants met the diagnostic criteria, while 1.48% complained of severe symptoms (frequency at least twice a week); however, only a few patients received treatment for RLS [3]. RLS lowers an individual’s quality of life as it causes low-quality sleep and insomnia because symptoms occur at night. However, only a few studies have investigated the efficacy of the current RLS treatment methods [4]. With regard to current Western medicine, dopamine was used as the primary treatment for RLS, but due to its side effects, it has recently been recommended to avoid the prescription of alpha-2-delta ligand anticonvulsants, such as pregabalin and gabapentin [5]. Moreover, RLS is a chronic disease, and the long-term use of drugs for its treatment is inevitable, which have their corresponding side effects [5]. Therefore, it has been suggested that Oriental Medicine can help improve the RLS symptoms. Currently, in addition to the acupuncture treatment for RLS, numerous related studies, such as collaborative and manual treatments, have been widely reported. Although some review papers on acupuncture treatment for RLS have already been published, the target of their analyses was limited to Chinese studies [6] or was not limited to randomized controlled trials (RCTs) [7]. Thus, it was difficult to be implemented in actual treatments due to its low effectiveness. To examine the current status of acupuncture treatment for RLS and to provide an opportunity to systematize acupuncture treatment, the aim of this study is to analyze the findings of domestic and international RCT studies in relation to the acupuncture treatment for RLS that provide basic data for domestic clinical trials in the future.

1. Selection and exclusion criteria

The inclusion criteria are as follows: (1) studies involving patients diagnosed with RLS based on clinical symptoms; (2) RCTs on acupuncture, regardless of the stimulation method used (acupuncture, electroacupuncture, acupotomy, pharmacoacupuncture), types of needles, duration time of acupuncture, stimulating points (e.g., tender points, trigger points, acupoints on meridian), or number of treatments; and (3) studies on the intervention of acupuncture only in the treatment group.

The exclusion criteria are as follows: (1) duplicate studies; (2) studies which were not RCTs; (3) studies whose full text cannot be procured; (4) studies published in non-academic journals; (5) studies not related to acupuncture or RLS; (6) studies using effective acupuncture as an intervention in both treatment and control groups (e.g., comparison between acupuncture and special acupuncture); (7) studies with difficulty in performing acupuncture owing to its complexity; and (8) studies using treatment interventions along with acupuncture that are not common.

No restrictions on the language, date of publication, country of publication of the study, and the age, sex, or race of the patients were established.

2. Databases and search methods

Relevant studies published from January 1, 2007, to December 31, 2022, were searched in the follow databases: the Cochrane Library, PubMed, Embase, CNKI, KISS, RISS, and OASIS. The terms including [(“restless legs syndrome” OR “Willis Ekbom disease”) AND (“acupuncture” OR “needle therapy”)] were used as the search keywords.

3. Risk-of-bias assessment

Three investigators independently used seven questions from the Cochrane risk-of-bias (RoB) tool to evaluate the RoB in the included RCTs [8]. The questions covered random sequence generation (selection bias), allocation concealment (selection bias), blinding of participants and personnel (performance bias), blinding of outcome assessment (detection bias), incomplete outcome data (attrition bias), selective reporting data (attrition bias), and other potential biases, which were rated as high, low, or unclear. If the opinions differ, the results were derived by agreement with the corresponding author or third party.

1. Study selection

The search procured 21 studies from the Cochrane Library, 28 from PubMed, 29 from Embase, 58 from CNKI, 5 from KISS, 3 from RISS, and 14 from OASIS.

A total of 158 studies were retrieved. Of these, 46 were duplicates. Of the remaining 112 studies, 71 were not RCTs, 2 had no full text, and 3 were published in nonacademic journals. Of the 36 remaining studies, 8 were not related to acupuncture or RLS, whereas 11 used acupuncture as an intervention in both the treatment and control groups. Moreover, six studies were excluded because the acupuncture method used was very special, making it difficult to apply to treatment, whereas five studies were judged to have a complex accompanying treatment intervention. Subsequently, six studies were included after considering the patient groups and abstracts (Fig. 1).

Figure 1. Flow diagram of the study selection process of this review. RCT, randomized controlled trial.

2. Risk of bias

The Cochrane RoB tool was used to assess the RoB in seven RCTs. The results are presented in graphs and summarized using RevMan 5.4.1 (Figs. 2, 3).

Figure 2. Risk of bias (RoB) summary: judgments of the review authors about each RoB item for each included study.

Figure 3. Risk-of-bias (RoB) graph: judgments of the review authors about each RoB item presented as percentages across all included studies.

One study [9] was rated as “low” RoB because the patients were randomly divided and used double crossover RCT. Five studies [10-14] were rated as “unclear” because the randomization methodology was not mentioned.

All studies [9-14] were rated as “unclear” in the allocation concealment because all studies did not describe the concealment of assignment to reduce bias.

One study [9] was rated as “low” RoB because the practitioners and patients were blinded by crossover blinding. Furthermore, five studies were rated as “high” RoB because they did not mention the use of blinding.

All six studies [9-14] did not properly describe the method of rater blinding and were rated as “unclear.”

All studies [9-14] had no missing data and were rated as “low” RoB.

All six studies [9-14] reported all outcomes expected from their experimental design and were rated as “low.”

All six studies [9-14] were rated as “low” because no additional biases were identified.

3. The overview of selected studies

The six selected RCT studies published between 2007 and 2022 were retrieved from CNKI, the Cochrane Library, and PubMed and were reported in Chinese and English. The RCTs were conducted in China (n = 4), Iran (n = 1), and Japan (n = 1).

Overall, 414 participants with RLS were included in the six RCTs. The study with the most participants comprised 158 individuals, while the study with the least participants comprised 8 individuals.

The selection and exclusion criteria were applied in all six studies. In all studies, RLS was diagnosed based on the following characteristic symptoms: (1) leg discomfort and urge to move them were experienced; (2) symptoms appeared or worsened when standing still in one position; (3) walking or moving the legs relieved the symptoms; and (4) symptoms appeared or worsened only at night.

Li et al. [10] was diagnosed with RLS based on the RLS Standard diagnostic criteria published in 1999. Moreover, the participants without abnormalities in the nervous system were included. Wu et al. [11] included individuals presenting with the clinical symptoms of RLS for a period of more than 6 months. Tang and Tang [12] also included patients based on the latest diagnostic criteria published by IRLSSG in 2003. They included individuals who had normal neurological examination findings. Raissi et al. [13] included patients who were diagnosed with RLS, had more than 20 points in the IRLSSG Rating scale (IRLSRS) questionnaire, and had symptoms lasting for more than 6 months. Fukutome and Murashima [9] included individuals who had symptoms of sleeplessness at night, those with insomnia due to leg discomfort and not due to other illnesses, those with symptoms persisting for at least 2 weeks, and those aged at least 20 years old. In Fan et al.’s [14] study, the patients were selected according to the RLS diagnosis and treatment guidelines published in Nanjing in 2021 [15]. The guidelines included tingling and itching in the lower extremities and leg discomfort during rest.

The general characteristics of the treatment and control groups in all studies were similar and indicated no statistically significant difference (Table 1).

Table 1 . Overview of the selected studies.

Author (y)	Type	Country	Sample size	Criteria	Age, mean (± SD)	VAS, mean (± SD)
Fukutome (2022) [9]	Crossover RCT	Japan	TG 4 CG 4	25–81 y Symptoms (> 2 wk)	-	TG 3.04 (3.71) CG 9.39 (1.65)
Li (2007) [10]	RCT	China	TG 34 CG 20	21–72 y RLS standard (1999)	-	-
Wu (2008) [11]	RCT	China	TG 79 CG 79	40–84 y Symptoms (> 6 mo)	TG 56.8 (11.14) CG 55.2 (10.31)	-
Tang (2009) [12]	RCT	China	TG 30 CG 28	23–71 y International RLS standard (2003)	-	-
Raissi (2017) [13]	RCT	Iran	TG 23 CG 23	21–81 y IRLSRS (> 20) Symptoms (> 6 mo)	TG 47.65 (13.93) CG 49.13 (15.57)	TG 7.78 (2.57) CG 9.13 (1.84)
Fan (2022) [14]	RCT	China	TG 45 CG 45	45–56 y RLS standard in Nanjing	-	-

SD, standard deviation; VAS, visual analog scale; RCT, randomized controlled trial; TG, treatment group; CG, control group; RLS, restless legs syndrome; IRLSRS, International Restless Legs Syndrome Rating Scale; -, not applicable..

4. Interventions of the selected studies

Of the six selected studies, one study used acuinjection [9] and five used acupuncture as the intervention method of choice for the treatment groups (Table 2). In five studies, oral Western medicine intervention was used in the control groups instead of acupuncture treatment [10-14]. In one study [12], sham acuinjection containing a normal saline solution was performed at any point. Treatment was usually performed daily [11,12,14] and typically lasted for 4 to 6 weeks, with a range of 1 day to 6 months (Table 3). Stainless steel and sterile acupuncture needles were used in five studies, except in one study that used acuinjection. A 27-gauge needle syringe was used in a study using acuinjection [9]. The needle retention time was usually 20 to 30 minutes. Moreover, one study had no retention time [9]. The depth of the needle varied across studies, ranging from 0.5 cm to 3.0 cm, whereas for the studies that were conducted in China, this was not specified [10-12,14]. In general, 57 acupoints were used in the six studies, wherein the most commonly used acupoints were ST 36 and SP 6 [9-14], followed by SP 10 [10,12-14], KI 3 [9,10,13,14], and GB 34 (Table 4) [10,12-14]. Furthermore, the most commonly used meridian was BL (Table 5).

Table 2 . Interventions and results of the selected studies.

Author (y)	Intervention	Control	Outcome measurement	Results	Adverse effects
Fukutome (2022) [9]	Acuinjection	Sham acuinjection	1. Reduction in PLMI 2. Reduction in VAS	1. No difference 2. TG > CG (p < 0.001)	No
Li (2007) [10]	Acupuncture	Western medicine (alprazolam)	1. Increase in the total efficacy rate	1. TG > CG (p < 0.01)	Not mentioned
Wu (2008) [11]	Acupuncture	Western medicine (levodopa)	1. Increase in the total efficacy rate	1. TG > CG (p < 0.05)	No
Tang (2009) [12]	Acupuncture (+ levodopa)	Western medicine (levodopa)	1. Increase in the total efficacy rate 2. Increase in sleep time 3. Decrease in the number of awakening	1. TG > CG (p < 0.05) 2. TG > CG (p < 0.05) 3. TG > CG (p < 0.05)	No
Raissi (2017) [13]	Acupuncture (+ gabapentin)	Western medicine (gabapentin)	1. Reduction in IRLSRS 2. Reduction in PSQI 3. Reduction in VAS	1. TG > CG (p < 0.001) 2. TG > CG (p < 0.001) 3. TG > CG (p < 0.001)	Not mentioned
Fan (2022) [14]	Acupuncture (+ pregabalin)	Western medicine (pramipexole)	1. Increase in the total efficacy rate 2. Increase in QoL 3. Reduction in the severity score before and after treatment	1. TG > CG (p < 0.05) 2. TG > CG (p < 0.05) 3. No difference	Not severe events

PLMI, periodic leg movement index; VAS, visual analog scale; TG, treatment group; CG, control group; IRLSRS, International Restless Legs Syndrome Rating Scale; PSQI, Pittsburgh Sleep Quality Index; QoL, quality of life..

Table 3 . Implementation of acupuncture intervention.

Author (y)	Periods	Frequency	Acupoints	Acupuncture needle	Depth of insertion	Needle remaining time
Fukutome (2022) [9]	1 d	1 trial	BL 60, GB 41, ST 6, SP 3	27-gauge needle	0.5 cm	No
Li (2007) [10]	10 d	3 trials/wk	CV 9, GB 34, LR 3, SP 6, SP 9, SP 10, ST 25, ST 36	Not mentioned	Not mentioned	20 min
Wu (2008) [11]	1 mo	7 trials/wk	BL 23, BL 25, BL 26, BL 54, GB 39, KI 3, SP 9, SP 6, ST 36	Sterile needle	Not mentioned	30 min
Tang (2009) [12]	1 mo	7 trials/wk	GB 20, GB 34, GB 39, GB 40, GB 43, LR 3, LR 5, KI 3, SP 10, SP 6, ST 36	Sterile needle	Not mentioned	25 min
Raissi (2017) [13]	8 wk	3 trials/wk	BL 18, BL 23, BL 56, BL 57, BL 64, GB 34, GB 39, KI 3, SP 5, SP 6, SP 10, ST 34, ST 36	Sterile needle	1.5–3.0 cm	30 min
Fan (2022) [14]	6 mo	7 trials/wk	BL 18, BL 23, BL 40, CV 9, GB 34, LR 3, KI 3, SP 6, SP 9, SP 10, ST 25, ST 36	Not mentioned	Not mentioned	30 min

BL, bladder meridian; GB, gallbladder meridian; ST, stomach meridian; SP, spleen meridian; CV, conception vessel; LR, liver meridian; KI, kidney meridian..

Table 4 . Frequency of acupoints in the studies.

Frequency	Acupoints
6	SP 6, ST 36
4	GB 34, KI 3, SP 10
3	BL 23, GB 39, LR 3, SP 9
2	BL 18, CV 9, ST 25
1	BL 25, BL 26, BL 40, BL 54, BL 57, BL 60, BL 64, GB 20, GB 40, GB 41, GB 43, LR 5, SP 5, ST 34

SP, spleen meridian; ST, stomach meridian; GB, gallbladder meridian; KI, kidney meridian; BL, bladder meridian; LR, liver meridian; CV, conception vessel..

Table 5 . Frequency of meridians used in the studies.

Frequency	Meridians	Acupoints
10	Bladder meridian (BL)	BL 18, BL 23, BL 25, BL 26, BL 40, BL 54 , BL 56, BL 57, BL 60, BL 64
6	Gallbladder meridian (GB)	GB 20, GB 34, GB 39, GB 40, GB 41, GB 43
4	Spleen meridian (SP)	SP 5, SP 6, SP 9, SP 10
3	Stomach meridian (ST)	ST 25, ST 34, ST 36
2	Liver meridian (LR)	LR 3, LR 5
1	Kidney meridian (KI)	KI 3
1	Conception vessel (CV)	CV 9

5. Assessment indicators

As for the assessment indicators, the efficacy rate reported by the patients immediately after the treatment was the most commonly used indicator [10-12,14], which indicated the extent of improvement that was achieved in relation to the value obtained before treatment. Three studies evaluated three items, including remarkable effect, improvement, and invalidity [11,12,14], whereas one study evaluated four items, including cure, remarkable effect, improvement, and invalidity [10] (Table 6). Li et al. [10] reported that a significant increase was observed in the cure/improvement items of the treatment group than in the control group and that an increase in the invalidity item appeared only in the control group. Tang and Tang [12] showed a significant difference in the invalidity and improvement rate between the treatment and control groups. In the study of Wu et al. [11], significant differences in the remarkable efficacy and invalidity rates among the studies analyzed were observed, indicating the highest improvement rate in the control group among all studies. In the study by Fan et al. [14], the difference between the treatment and control groups was not significant in all items.

Table 6 . The outcome of the efficacy rate in the studies.

Author (y)	Treatment (%)	Control (%)	p-value
Fukutome (2022) [9]	1. Remarkable effect: Acu + levodopa 15.0 2. Improvement: Acu + levodopa 27.0 3. Invalidity: Acu + levodopa 3.0 4. Total effective rate: Acu + levodopa 93.3	1. Western medicine 11.0 2. Western medicine 24.0 3. Western medicine 10.0 4. Western medicine 77.8	< 0.05
Li (2007) [10]	1. Cure: Acu 50.9 2. Remarkable effect: Acu 20.6 3. Improvement: Acu 23.5 4. Invalidity: Acu 0.0 5. Total effective rate: Acu 100.0	1. Western medicine 40.0 2. Western medicine 20.0 3. Western medicine 15.0 4. Western medicine 25.5 5. Western medicine 75.0	< 0.01
Wu (2008) [11]	1. Remarkable effect: Acu 53.1 2. Improvement: Acu 38.0 3. Invalidity: Acu 8.9 4. Total effective rate: Acu 91.1	1. Western medicine 0.0 2. Western medicine 30.4 3. Western medicine 69.6 4. Western medicine 30.4	< 0.05
Fan (2022) [14]	1. Remarkable effect: Acu + pregabalin 53.1 2. Improvement: Acu + pregabalin 38.0 3. Invalidity: Acu + pregabalin 8.9 4. Total effective rate: Acu + pregabalin 95.56	1. Western medicine 0.0 2. Western medicine 30.4 3. Western medicine 69.6 4. Western medicine 80.0	< 0.05

Acu, acupuncture..

The visual analog scale (VAS) scores (0_10) was used as an assessment indicator in the study of Raissi et al. [13] to evaluate the degree of pain, with the higher score indicating greater pain. The VAS score showed a significant decrease in the treatment group immediately after treatment, suggesting a significant difference between the treatment and control groups; however, the difference was minimal during the 8-week follow-up. In a study by Fukutome and Murashima [9], the VAS score was the lowest in both the treatment and control groups immediately after treatment and subsequently increased every 10 minutes. However, the VAS score was significantly higher in the treatment group than in the control group (Table 7).

Table 7 . The outcome of VAS in the studies.

Author (y)	Treatment	Control	p-value
Fukutome (2022) [9]	Acuinjection 3.04 ± 3.71	Sham acuinjection 9.39 ± 1.65	< 0.001
Raissi (2017) [13]	Acu 3.47 ± 2.25	Western medicine 5.17 ± 3.47	< 0.001

VAS, visual analog scale; Acu, acupuncture..

One study used the IRLSRS, which numerically evaluates the improvement of the RLS symptoms [13], and the difference in the scores before and after treatment was larger than that of the control group. In a treatment period of eight weeks, the treatment group maintained a lower IRLSRS score than the control group, which resulted in significant results.

In one study, the periodic leg movement index (PLMI) was used [9], which is defined as the total number of PLMs per hour of the suggested immobilization test (SIT) and is an indicator of how often periodic limb movements per hour appear in the non-surface state. In the PLMI evaluation, no significant increase in the scores was observed between the treatment and control groups.

Sleep-related indicators were used across three studies according based on RLS characteristics, which mainly appear at night (Table 8). In a previous study [12] that investigated the number of sleep and frequency of awakening of patients before and after treatment, the sleep time increased significantly and the frequency of awakening decreased significantly in the treatment group as compared with the values before treatment.

Table 8 . The outcome of sleep-related indicators in the studies.

Author (y)	Assess indicator	Treatment	Control	p-value
Tang (2009) [12]	1. Sleep time 2. Awakening time	1. Acu + levodopa 6.47 ± 1.44 2. Acu + levodopa 2.12 ± 0.81	1. Western medicine 5.28 ± 1.65 2. Western medicine 3.28 ± 1.22	< 0.05
Raissi (2017) [13]	PSQI	Acu + gabapentin 9.39 ± 5.77	Western medicine 6.65 ± 6.31	< 0.001
Fan (2022) [14]	Severity score on sleep	Acu + pregabalin 0.98 ± 0.05	Western medicine 1.93 ± 0.40	< 0.001

Acu, acupuncture; PSQI, Pittsburgh Sleep Quality Index..

The Pittsburgh Sleep Quality Index (PSQI) was used in a study by Raissi et al. [13]. Regarding the PSQI score measured immediately after treatment and 8 weeks after treatment, the treatment group showed a significant increase in the PSQI score, suggesting an increase in sleep quality.

The severity score before and after treatment of RLS patients based on the sleep disorder scores was used in the study of Fan et al. [14]. No statistically significant difference in the severity scores before and after treatment was observed between the treatment and control groups.

The study of Fan et al. [14] used a quality of life indicator questionnaire that comprised four items: physical, psychological, social, and material functions. They reported a statistically significant increase and improved effect in terms of quality of life in the treatment group.

6. Adverse events

Altogether, 2 out of the 6 studies did not mention any side effects [10,13], and 3 studies reported no side effects (Table 1) [9,11,12]. In the study by Fan et al. [14], side effects were reported. In the treatment group receiving a combination treatment of acupuncture and pregabalin, 2% of the patients reported dizziness, 1% complained of muscle pains, 1% had cramps, and 4% had joint pains (p = 0.048).

In the present study, we evaluated whether acupuncture has a clinical effect on RLS by reviewing relevant data from published RCTs. RLS is characterized by the following symptoms: (1) leg discomfort and urge to move them were experienced; (2) symptoms appeared or worsened when standing still in one position; (3) walking or moving the legs relieved the symptoms; and (4) symptoms appeared or worsened only at night [16]. The diagnosis of RLS is primarily made if the four clinical symptoms are present and if tests, such as SIT that record motor and sensory abnormalities in the anterior bone muscle, such as electromyogram, polysomnography, and electrooculogram, reveal positive findings. RLS is believed to be caused by iron deficiencies and abnormalities in the dopamine systems; thus, iron preparations or dopaminergic drugs are prescribed as basic medical treatments [17]. However, the use of dopamine can also cause side effects, such as rebound effects, augmentation, and delayed tachycardia. Additionally, its additional administration may be dangerous or burdensome due to diseases that precede and accompany RLS [18].

In Oriental Medicine, RLS can be categorized as “numbness,” “numbness by blood problem,” “numbness by cold,” and “Gyeong disease.” Moreover, Gyeong disease is caused by the blockage of the meridian system due to an external cause. The Yellow Emperor’s Inner Canon explains the reason for numbness to occur: “When a person is in a lying position, blood enters the liver and flows to the feet, allowing him to walk. When you go out and breathe, you inhale wind, blood coagulates on the skin, causing numbness, and blood vessel does not circulate to the feet in those with blocked blood vessels, causing numbness. If the blood does not circulate, the symptoms of numbness appear [19].” Moreover, another study explained why these symptoms are present: “Both the upper and lower limbs have the qi on the stomach. Moreover, if there is a disease in the spleen, the essence cannot circulate to the stomach, and if so, the essence cannot circulate smoothly to the limbs [20].” In Oriental Medicine, it is believed that the liver controls the muscles and stores blood. Moreover, spleen controls the limbs and commands the flesh. The liver and spleen have the same roots. Especially, the lower extremities are associated with the kidney. In summary, the lower extremities become numb due to disorders in the liver, spleen, and kidney [21].

Acupuncture is one of most commonly used non-pharmaceutical methods for RLS treatment. It can relieve symptoms of RLS by promoting qi that is, energy, which induces blood circulation and the release of pain-relieving chemicals. Overall, 157 studies were obtained from the seven domestic and foreign databases. In the present review, a total of six studies were selected for analysis in accordance with the inclusion and exclusion criteria. In the selected study, the diagnostic criteria for RLS were diverse, and various international standards based on the four characteristics and clinical symptoms of RLS were mainly used to diagnose the disease. In the study of Wu et al. [11], only patients with RLS symptoms persisting for more than 6 months were included. The study of Tang and Tang [12] included patients with persistent RLS symptoms for more than 1 year, whereas the study of Fukutome and Murashima [9] included adults over the age of 20 years. Acupuncture was used as an intervention in all analyzed studies, except for Fukutome and Murashima’s [9] study that utilized acuinjection. Moreover, acupuncture treatment for RLS resulted in a statistically significant increase in the efficacy rate, significant decrease in the VAS scores, and significant results in the questionnaires and tests. These results indicated that acupuncture not only improves the quality of life of RLS patients but also is effective in improving the RLS symptoms. However, further clinical studies are needed to determine the physiological and pathological changes caused by acupuncture. Of the 27 acupoints used among the six studies, acupuncture was mainly applied to the lower extremities (19 acupoints in the lower extremities). Moreover, the studies focused on the five acupoints in the waist/hip, two acupoints in the abdomen, and one acupoint in the head. The most commonly used accupoints in the studies were ST 36 and SP6, followed by SP 10, KI 3, and GB 34, which are all located in the lower extremities. Particularly, with regard to ST 36, the animal experimental studies have revealed that the combination of electroacupuncture can increase the dopamine secretion in dopaminergic neurons and that physical stimulation will help improve the RLS symptoms because ST 36 is located on the tibialis anterior muscle [22]. Moreover, stimulating SP 6 facilitates the removal of wind and dampness in the meridian system that cause pain and allows the passage of the meridian through the blocked qi and blood flow [23]. The most frequently used meridian type was BL, followed by GB and SP. The acupoint in the meridian system controls the pain in the area where the meridian flows. The BL meridian passes through the waist and subsequently through the back of the thighs and calves and the outside of the feet. Since the GB and SP meridian also pass through the inner side of the lower extremities, they have been widely used due to the nature of RLS that is characterized by the presence of symptoms in the lower extremities.

The side effects which mainly included minor symptoms, such as dizziness, joint pain, and muscle pain, were reported in one study [14].

However, the present study has several limitations. First, the present study could have included more studies conducted in many countries, but RCTs are only implemented in a very limited number of countries. Second, the number of RCTs was very small. Third, the quality of the studies was not evaluated. Despite these challenges, our study results showed that acupuncture had a positive effect on RLS. However, further domestic and international research on RLS is needed to confirm our findings.

In the six RCT studies on acupuncture treatment for RLS, the following conclusions were obtained: First, all six RCTs selected in this study revealed that acupuncture has statistically significant effects on RLS symptoms. Second, acupuncture treatment can be effective for RLS patients in terms of improving their lower extremity symptoms and overall quality of life. Third, the most commonly used meridian was the BL meridian, the most used acupoints were ST 36 and SP 6, and most of the studies used acupoints located in the lower extremities. Fourth, acupuncture is a safe treatment method for RLS, as no significant side effects of acupuncture treatment for RLS were noted in the present study. Fifth, further research is needed to confirm the effectiveness of acupuncture treatment on RLS.

Conceptualization: GEC. Data curation: GEC, AK, YJL. Formal analysis: GEC, HWK, HJJ. Investigation: GEC, HWK, HJJ, JEC. Methodology: GEC, WYK. Project administration: GEC. Supervision: WYK. Writing – original draft: GEC. Writing – review & editing: GEC, HWK, HJJ.

The authors have no conflicts of interest to declare.

None.

This research did not involve any human or animal experiment.