Table 2.
Acupoints and operating parameters for electroacupuncture treatment.
| Acupoint | Meridian | Laterality | Location | Needling direction and depth | Manipulation | Electroacupuncture connection |
|---|---|---|---|---|---|---|
| LI15 (Jianyu) | Large Intestine meridian of hand-yangming | Affected side | On the shoulder, in the depression anterior and inferior to the acromion; when the arm is abducted, located in the depression between the anterior border of the acromion and the greater tubercle of the humerus. | Perpendicular insertion, approximately 0.8–1.5 cun. | Mainly reducing manipulation with twirling, aiming to elicit de qi sensations such as soreness, numbness, distension, heaviness, or local radiating sensation. | Output channel 1; connected with LI14. |
| LI14 (Binao) | Large Intestine meridian of hand-yangming | Affected side | On the lateral aspect of the upper arm, near the insertion of the deltoid muscle; located on the line connecting LI15 and LI11. | Perpendicular insertion, approximately 0.8–1.5 cun. | Mainly reducing manipulation with twirling, aiming to elicit de qi. | Output channel 1; connected with LI15. |
| SJ14 (Jianliao) | Sanjiao meridian of hand-shaoyang | Affected side | On the shoulder, in the depression posterior and inferior to the acromion when the arm is abducted. | Perpendicular insertion, approximately 0.8–1.2 cun. | Mainly reducing manipulation with twirling, aiming to elicit de qi. | Output channel 2; connected with SJ11. |
| SJ11 (Qinglengyuan) | Sanjiao meridian of hand-shaoyang | Affected side | On the posterior aspect of the upper arm, 2 cun proximal to the olecranon, on the line connecting the olecranon and SJ14. | Perpendicular insertion, approximately 0.5–1.0 cun. | Even reinforcing-reducing manipulation, aiming to elicit local soreness and distension. | Output channel 2; connected with SJ14. |
| SJ5 (Waiguan) | Sanjiao meridian of hand-shaoyang | Affected side | On the dorsal aspect of the forearm, 2 cun proximal to the dorsal wrist crease, between the radius and ulna. | Perpendicular insertion, approximately 0.5–1.0 cun. | Even reinforcing-reducing manipulation, aiming to elicit local soreness and distension. | Not connected to electroacupuncture; conventional needle retention only. |
| ST38 (Tiaokou) | Stomach meridian of foot-yangming | Contralateral to the affected shoulder | On the anterolateral aspect of the lower leg, 8 cun inferior to ST35 and one finger-breadth lateral to the anterior crest of the tibia. | Perpendicular insertion toward Chengshan (BL57), approximately 1.0–2.0 cun. | Mainly reducing manipulation with twirling, aiming to elicit de qi sensations such as soreness, numbness, distension, and heaviness. | Not connected to electroacupuncture; conventional needle retention only. |
All acupoints will be located according to the WHO Standard Acupuncture Point Locations. Output channels 1 and 2 refer to two independent electrical output channels of the electroacupuncture device. In this study, output channel 1 will connect LI15 and LI14 on the affected side, and output channel 2 will connect SJ14 and SJ11 on the affected side. SJ5 on the affected side and ST38 contralateral to the affected shoulder will not be connected to the electroacupuncture device and will receive conventional needle retention only. Both groups will receive the same acupoint prescription, needling procedures, and electroacupuncture connection pattern; the only planned between-group difference will be the stimulation frequency (2 Hz vs. 100 Hz). BL, Bladder meridian; EA, electroacupuncture; LI, Large Intestine meridian; SJ, Sanjiao meridian; ST, Stomach meridian; TDP, specific electromagnetic spectrum lamp; WHO, World Health Organization; cun, a proportional body unit used in acupuncture point location; de qi, the characteristic needling sensation associated with acupuncture stimulation.