Effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries

Abstract

BACKGROUND

The rotator cuff is located below the acromion and deltoid muscles and comprises multiple tendons that wrap around the humeral head, maintaining shoulder joint stability.

AIM

To explore the effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries.

METHODS

We selected 97 patients with rotator cuff injuries treated in the People's Hospital of Yuhuan from February 2020 to May 2023. Patients were grouped using the envelope method.

RESULTS

After treatment, the study group’s treatment effective rate was 94.90% (46/49 patients), significantly higher than that in the control group (79.17%, 38/48 cases; P < 0.05). Before treatment, there was no difference in Constant Murley Score (CMS) scores, shoulder mobility, or 36-Item Short Form Health Survey (SF-36) scale scores (P > 0.05). Compared with those before treatment, the CMS scores (including pain, daily living ability, shoulder mobility, and muscle strength), all aspects of shoulder mobility (forward flexion, posterior extension, external rotation, internal rotation), and SF-36 scale scores (including physiological, psychological, emotional, physical, vitality, and health status) were higher in both groups after treatment and significantly higher in the study group (P < 0.05). There was no difference in the occurrence of complications between the two treatment groups (P > 0.05).

CONCLUSION

Electroacupuncture combined with rehabilitation techniques has a good treatment effect on patients with rotator cuff injuries, helps accelerate the recovery of shoulder function, improves the quality of life, and is highly safe.

Key Words: Electroacupuncture therapy; Rehabilitation technique; Rotator cuff injury; Shoulder joint function

Core Tip: This study included 97 patients with rotator cuff injuries treated in the People's Hospital of Yuhuan from February 2020 to May 2023. Patients were grouped using the envelope method. Forty-eight patients in the control group were treated with rehabilitation techniques, whereas forty-nine patients in the study group were treated with electroacupuncture combined with rehabilitation techniques. A follow-up was conducted for 6 months, assessing the patients at the last follow-up, comparing the shoulder Constant Murley Score, shoulder mobility, and 36-Item Short Form Health Survey scores before and 6 months after treatment. Complications in the patients were recorded until the follow-up period. The results showed that electroacupuncture combined with rehabilitation techniques had a good treatment effect on patients with rotator cuff injuries, aiding in the acceleration of shoulder function recovery, improving quality of life, and demonstrating high safety.

INTRODUCTION

The rotator cuff is located below the acromion and deltoid muscles. It comprises multiple tendons that encircle the humeral head and help maintain stability in the shoulder joint. Trauma and overexertion can lead to excessive rotation of the greater tuberosity of the humerus, causing strains in the muscles and ligaments, local blood supply issues, and rotator cuff injuries. Rotator cuff injuries account for approximately 17% to 41% of shoulder joint lesions[1,2]. Rehabilitation therapy is commonly used in Western medicine to treat rotator cuff injuries. Rehabilitation techniques can help reduce muscle adhesion, improve local blood flow, and enhance muscle strength, ultimately aiding in the recovery of shoulder joint function and reducing pain. However, some patients do not respond well to rehabilitation therapy and may find the pain intolerable, leading to reduced treatment compliance and, in some cases, the need for surgical intervention. Some studies suggest that traditional Chinese medicine may have a specific complementary effect in treating rotator cuff injuries, and it is recommended to consider a combination of traditional Chinese and Western medicine for treatment[3,4].

In ancient Chinese medicine books, shoulder cuff injury is categorized as “Bi syndrome” and “shoulder coagulation syndrome.” Trauma caused by falls and impacts can damage the shoulder cuff, causing blood to overflow and remain outside the meridian. Additionally, invasion of wind, cold, and dampness pathogens can lead to cold coagulation and qi stagnation, blocking the shoulder cuff and causing local blood flow obstruction and pain. The treatment principle is to promote qi and blood circulation, disperse blood stasis, and relieve pain. Currently, treatments such as acupuncture, moxibustion, massage, external application of Chinese medicine, and oral administration are used to treat rotator cuff injuries[5-8]. Electroacupuncture is a type of acupuncture that combines traditional acupuncture with electrical stimulation therapy. It can provide local pain relief by stimulating neurons. Electroacupuncture is commonly used to treat sports injuries, rheumatism, and other conditions[9]. Previous studies have utilized electroacupuncture to address shoulder joint inflammation, yielding good anti-inflammatory and analgesic effects[10-12]. This study examined the impact of electroacupuncture combined with rehabilitation techniques on shoulder joint function in patients with rotator cuff injuries.

MATERIALS AND METHODS

General information

Ninety-seven patients with rotator cuff injuries who were admitted in the People's Hospital of Yuhuan from November 2020 to May 2023 were included in the study. The patients were categorized into two groups using the envelope method: 48 patients in the control group received electroacupuncture treatment, whereas 49 patients in the study group received electroacupuncture combined with rehabilitation techniques. An analysis of the intergroup data showed no difference (P > 0.05, Table 1). This study was approved by the ethics committee of our institution.

Table 1 General data comparison.

	Control group (n = 48)	Study group (n = 49)	χ2/t	P value
Age (years)	56.15 ± 5.16	56.77 ± 4.98	-0.602	0.548
Sex			0.828	0.363
Male	23 (47.92)	28 (56.47)
Female	25 (52.08)	21 (43.53)
Course of disease (days)	34.26 ± 5.15	35.48 ± 4.78	-1.210	0.229
Years of education (years)	9.15 ± 3.46	8.87 ± 2.98	0.427	0.670
The damage location			0.261	0.609
Left side	22 (45.83)	25 (51.02)
Off side	26 (54.17)	24 (48.98)
Cause of injury			0.922	0.820
Traffic injury	13 (27.08)	12 (24.49)
Pricking wound	14 (29.17)	11 (22.45)
Sports injury	4 (8.33)	5 (10.20)
Other	17 (35.42)	21 (42.86)
Degree of injury			0.962	0.327
Part of the damage	33 (68.75)	29 (59.18)
Small and medium-sized injuries	15 (31.25)	20 (40.82)

Inclusion criteria

We included all patients who underwent a magnetic resonance imaging examination that revealed a rotator cuff tear, with partial or minor injuries accompanied by shoulder joint pain[13]; patients appropriate for conservative treatment; patients aged between 18 and 65 years; and patients without other major diseases and cleared to receive electroacupuncture.

Exclusion criteria

We excluded patients with imaging findings suggestive of shoulder joint fractures or severe rotator cuff tears requiring surgical treatment; patients with poor compliance and who were unable to complete relevant rehabilitation training according to medical advice; patients with shoulder joint pain caused by other diseases; patients who received conservative treatment before surgery without significant improvement and subsequently switched to surgical treatment; and patients with severe complications occurring during treatment and unable to continue treatment.

Treatment interventions

The control group received rehabilitation treatment, including immobilizing the upper limb on the affected side during the acute phase. Patients were instructed to perform fist clenching, elbow flexion, clock swinging, and circular movements. One week later, they were trained in upper limb muscle isometric and isotonic contractions. During the remission period, passive training was the main approach, with patients engaging in passive activities such as external rotation and adduction of the shoulder joint to prevent pain. The doctor massaged the muscle groups around the shoulder joint using fingertips or the greater or lesser thenar, gradually increasing the intensity from light to heavy and then decreasing from heavy to light. Throughout rehabilitation, patients were guided to actively perform various plane movements and expand their range of motion as much as possible without causing pain. Equipment for shoulder sleeve stability training and resistance training were also used.

The study group received electroacupuncture combined with rehabilitation techniques similar to those used in the control group. The selected acupoints for electroacupuncture on the affected side included Shoulder Zhen, Shoulder Liao, Shoulder Qi, Tianzong, Shoulder Front, and Arm Qi. The patient was guided to sit, the local skin was disinfected, and a filiform needle (0.25 mm × 40 mm) was used to puncture each acupoint using the flat tonifying and purging technique. The needle handles of Shoulder Zhen, Shoulder Liao, Shoulder Qi, Tianzong, and other acupoints were connected to a Han’s HANS-200 electroacupuncture instrument. The parameter settings were as follows: frequency, 100 Hz; waveform, continuous wave; and stimulation intensity, < 3 mA. The stimulation time was adjusted based on the patients’ tolerance, with a maximum of 30 minutes. Electroacupuncture treatment was administered once a day for 4 weeks in both groups.

Observation indicators

All patients were followed up for 6 months to evaluate the treatment effect. We compared the shoulder Constant Murley Score (CMS), shoulder range of motion, and the 36-Item Short Form Health Survey (SF-36) scores before and 6 months after treatment between the two groups. We also recorded the incidence of complications in patients until the follow-up period.

Therapeutic evaluation

The treatment was considered effective when the patient’s shoulder pain disappeared and muscle strength and joint activity significantly improved, restoring them to normal levels for recovery. The treatment was also considered effective if the patient experienced partial pain and recovered shoulder joint function and muscle strength. However, the treatment was considered ineffective if the patient’s shoulder joint function and muscle strength were not significantly improved or significant shoulder pain was present. We calculated various measures of treatment efficacy, including time to recovery, significant effects, the number of cases where treatment was effective, and the ratio of effective to total number of cases.

The CMS scale evaluates the patient’s pain (0-15 points), shoulder range of motion (0-40 points), daily living ability (0-20 points), and muscle strength (0-25 points)[14]. A higher score indicates better recovery of the patient’s shoulder joint function. The range of motion of the shoulder joint is analyzed based on imaging data of patients, comparing their flexion, extension, external rotation, and internal rotation.

The SF-36 scale evaluates patient’s quality of life, including physiological, psychological, emotional, physical, vitality, and health status[15]. The score is directly proportional to the quality of life.

Statistical analysis

Data were processed using SPSS 24.0 software, and χ² tests were conducted on quantitative data related to efficacy, sex, cause of injury, and injury side. We also analyzed the patients’ scores on various scales, including shoulder joint range of motion. Independent sample t-tests were used for between-group comparisons, and paired sample t-tests were used to compare pre- and post-treatment results within groups. Differences with a P < 0.05 were considered statistically significant.

RESULTS

Therapeutic effects

After treatment, 46 participants in the study group experienced improvements, resulting in an effective rate of 94.90% (46/49). In comparison, 38 participants in the control group showed improvements, indicating an effective rate of 79.17% (38/48, Table 2). The effective rate of the study group was significantly higher than that of the control group (P < 0.05).

Table 2 Comparison of treatment effects.

	Control group (n = 48)	Study group (n = 49)	χ2	P value
Recure	9 (18.75)	12 (24.49)	4.521	0.033
Excellence	15 (31.25)	15 (30.61)
Effective	14 (29.17)	19 (38.78)
Of no avail	10 (20.83)	3 (6.12)
Effective percentage	38 (79.17)	46 (94.90)

CMS scale scores

As shown in Table 3, there was no between-group difference in CMS scores at baseline (before treatment) (P > 0.05). After treatment, the pain, daily living ability, shoulder range of motion, and muscle strength scores were significantly improved in the study group compared to the control group (P < 0.05).

Table 3 Comparison of the scores of the Constant Murley Score scales.

	Control group (n = 48)	Study group (n = 49)	t	P value
Pain (points)
Before treatment	5.87 ± 1.45	5.68 ± 1.23	0.696	0.488
After treatment	9.33 ± 2.03a	11.59 ± 1.98a	-5.551	< 0.001
Daily living ability (points)
Before treatment	6.03 ± 1.32	6.31 ± 1.29	-1.057	0.293
After treatment	15.56 ± 3.12a	17.26 ± 2.89a	-2.785	0.006
Shoulder range of motion (points)
Before treatment	16.22 ± 3.16	15.99 ± 2.98	0.369	-10.072
After treatment	29.23 ± 2.31a	34.22 ± 2.56a	0.713	< 0.001
Muscle strength (score)
Before treatment	9.22 ± 2.13	9.29 ± 1.78	-0.176	0.861
After treatment	16.09 ± 2.02a	22.02 ± 1.69a	-15.649	< 0.001

^aP < 0.05.

Compared with the level before treatmen.

Mobility

Before treatment, the groups demonstrated similar measures of flexion, extension, external rotation, and internal rotation (P > 0.05). After treatment, both groups experienced an improvement in shoulder joint mobility, with the study group exhibiting significantly more improvement than the control group (P < 0.05, Table 4).

Table 4 Comparison of the shoulder range of motion.

	Control group (n = 48)	Study group (n = 49)	t	P value
Antexion (°)
Before treatment	117.26 ± 23.12	116.18 ± 22.12	0.235	-2.288
After treatment	131.03 ± 24.13a	142.96 ± 27.10a	0.815	0.024
After stretching (°)
Before treatment	61.13 ± 7.55	61.22 ± 8.45	-0.055	0.956
After treatment	80.16 ± 7.15a	94.12 ± 8.45a	-8.775	< 0.001
Extorsion (°)
Before treatment	21.22 ± 1.12	20.89 ± 1.56	1.195	0.235
After treatment	70.55 ± 1.15a	78.66 ± 2.45a	-20.797	< 0.001
Internal rotation (°)
Before treatment	15.11 ± 1.67	43.23 ± 1.64a	-3.394	0.001
After treatment	16.23 ± 1.58	55.26 ± 2.36a	-29.097	< 0.001

^aP < 0.05.

Compared with the level before treatment.

SF-36 scale scores

No significant between-group differences in SF-36 scale scores were observed before treatment (P > 0.05, Table 5). After treatment, the study group demonstrated significantly improved physiological, psychological, emotional, physical, vitality, and health status scale scores compared to the control group (P < 0.05).

Table 5 Comparison of the 36-Item Short Form Health Survey scales.

	Control group (n = 48)	Study group (n = 49)	t	P value
Physiology
Before treatment	54.89 ± 7.56	55.44 ± 8.98	-0.326	0.745
After treatment	71.55 ± 6.02a	84.22 ± 5.59a	-10.744	< 0.001
Psychology
Before treatment	56.78 ± 6.13	55.12 ± 6.55	1.288	0.201
After treatment	72.15 ± 6.18a	85.15 ± 4.15a	-12.186	< 0.001
Feeling
Before treatment	55.12 ± 5.13	55.46 ± 6.16	-0.295	0.769
After treatment	71.03 ± 2.99a	85.11 ± 3.46a	-21.425	< 0.001
Body
Before treatment	53.11 ± 2.16	52.99 ± 3.11	0.220	0.826
After treatment	70.65 ± 2.99a	81.23 ± 3.56a	-15.833	< 0.001
Vigour
Before treatment	55.12 ± 2.16	54.97 ± 1.87	0.366	0.715
After treatment	77.23 ± 2.46a	86.66 ± 3.16a	-16.377	< 0.001
Health status
Before treatment	55.16 ± 2.68	55.64 ± 3.64	-0.738	0.462
After treatment	74.26 ± 2.96a	83.87 ± 1.96a	-18.890	< 0.001

^aP < 0.05.

Compared with the level before treatment.

Complications

Six patients (12.24%) in the study group experienced complications during treatment, whereas nine patients (18.75%) in the control group experienced the same. There were no significant between-group differences in complications (P > 0.05, Table 6).

Table 6 Comparison of the occurrence of complications.

	Control group (n = 48)	Study group (n = 49)	χ2	P value
Secondary tear	1 (2.08)	0 (0.00)
Shoulder joint adhesion	1 (2.08)	1 (2.04)
Joint itch of skin	3 (6.25)	2 (4.08)
Infect	2 (4.17)	1 (2.04)
Numb	2 (4.17)	2 (4.08)
Total occurrence	9 (18.75)	6 (12.24)	0.785	0.376

DISCUSSION

Shoulder impingement is a common cause of shoulder joint dysfunction in athletes and the elderly. The incidence rate for people aged > 60 years is approximately 30%, whereas that for people aged > 80 years is as high as 60%[16]. Timely repair of rotator cuff injuries can reduce pain and improve shoulder joint function.

In clinical practice, rehabilitation training is commonly used for treating mild to moderate rotator cuff injuries. Studies have found that rehabilitation training can prevent shoulder soft tissue adhesion and muscle atrophy through passive, active, and massage techniques, which is beneficial for the recovery of shoulder joint function[17]. Factors such as the patient’s level of cooperation and pain tolerance can affect the effectiveness of the treatment process. Consequently, the efficacy of rehabilitation training alone can vary, and the overall treatment effectiveness may be unsatisfactory. Additionally, shoulder pain and mobility issues on the affected side can decrease the patient’s quality of life, causing significant discomfort[18].

Traditional Chinese medicine has a long history of treating rotator cuff injuries with external treatment methods, rehabilitation training, and other treatments. “The Origins of Miscellaneous Diseases: Rhinoceros Candle” describes this injury as sudden physical discomfort caused by falling, damaging both qi and blood circulation. Appropriate treatment of rotator cuff injuries should focus on promoting qi, improving blood circulation, dispersing blood stasis, and relieving pain[19].

Electroacupuncture involves passing a small electric current through acupuncture needles to stimulate local nerves and muscles. The acupoints targeted in this study for shoulder treatment are effective in dispelling wind, unblocking collaterals, relaxing tendons, and promoting joint health. Specifically, Shoulder Liao aids in dispelling wind and dampness, unblocking meridians, and activating collaterals. Additionally, stimulation of the shoulder joint clears heat, dispels wind, and enhances joint function. Tianzong serves to broaden the chest with qi, relax muscles, and activate collaterals, whereas Shoulder front clears meridians, reduces swelling, and relieves pain. Furthermore, stimulation of the arm aids in activating meridians, regulating qi, and reducing phlegm. The combined stimulation of various acupoints effectively unblocks qi and blood in the shoulder meridians, thereby preventing pain[20,21].

Even at the last follow-up, the study group demonstrated a higher treatment effective rate than the control group. After treatment, both groups showed improved CMS scores (pain, daily living ability, shoulder range of motion, and muscle strength), shoulder range of motion (flexion, extension, external rotation, internal rotation), and SF-36 scale scores (physiological, psychological, emotional, physical, vitality, and health status) compared to before treatment; however, the study group demonstrated more improvement.

Combined-modality treatment involving electroacupuncture and rehabilitation produced a superior therapeutic effect in patients with rotator cuff injuries, helping restore shoulder joint function and improve quality of life. This is because rehabilitation techniques can loosen shoulder tissue adhesions, prevent muscle atrophy within the shoulder strap musculature, improve microcirculation, and alleviate pain[22].

Importantly, the Shouzhen, Shouliao, Shougui, Tianzong, Shouqian, and Wugui, acupoints—stimulated through electroacupuncture—are all located around the shoulder joint. Acupuncture at these points can provide sustained and beneficial stimulation to the muscles and nerves surrounding the shoulder joint to promote local microvascular dilation, accelerate blood flow, and aid in the absorption and metabolism of inflammatory exudates, ultimately helping to reduce inflammation and tissue adhesion around the shoulder joint[23]. Microcurrent stimulation has a feedback effect on the central nervous system, releasing endogenous opioid peptides and producing a wide range of analgesic effects[24-26].

The combination of electroacupuncture and rehabilitation techniques for treating rotator cuff injuries demonstrates a synergistic effect through different mechanisms of action, leading to improved therapeutic effects. Alleviating shoulder pain symptoms in patients can enhance their willingness to participate in rehabilitation training, resulting in better recovery of shoulder joint mobility and an improved quality of life.

This study also found no difference in the incidence of complications such as secondary tearing, shoulder joint adhesion, skin itching, infection, and numbness between the two groups during treatment. Our findings suggest that combining electroacupuncture with rehabilitation techniques is effective and safe and does not increase the risk of complications.

CONCLUSION

The combination of electroacupuncture and rehabilitation techniques resulted in a good therapeutic effect on patients with rotator cuff injuries, helping restore shoulder joint function, improving quality of life, and demonstrating high safety.