Participants receive manual acupuncture at distal acupoints (SI3, SI5, TE4, BL60, BL62, GB40) on the contralateral side of the painful neck area for 25 minutes. During needle retention, patients perform active cervical spine movements (flexion, extension, lateral flexion, and rotation) for at least 10 minutes.

Participants receive electroacupuncture for 25 minutes at local acupoints (GB20-SI15 and GB21-LU7) on the painful side. After needle removal, patients perform active cervical spine movements (flexion, extension, lateral flexion, and rotation) for at least 10 minutes.

Manual acupuncture applied for 25 minutes at distal acupoints selected based on meridian diagnosis (SI3, SI5, TE4, BL60, BL62, GB40) on the contralateral side of the pain. During needle retention, participants performed active cervical spine movements (flexion, extension, lateral flexion, and rotation) for at least 10 minutes.

Pain intensity is assessed using a 100 mm Visual Analogue Scale (VAS), where ≤4 indicates no pain and 100 indicates the worst imaginable pain. The change in VAS score from baseline to each treatment day is recorded for comparison between groups.

The cervical range of motion (ROM) was measured for six movements: flexion, extension, right and left lateral flexion, and right and left rotation. Each movement was assessed using a goniometer, and the measured angles were converted into a limitation score ranging from 0 to 4 according to the following grading system:

• 0 - Normal ROM (flexion 45°-55°, extension 60°-70°, lateral flexion 40°-50°, rotation 60°-70°)
• 1 - Mild limitation (flexion 40°-44°, extension 55°-59°, lateral flexion 35°-39°, rotation 55°-59°)
• 2 - Moderate limitation (flexion 35°-39°, extension 50°-54°, lateral flexion 30°-34°, rotation 50°-54°)
• 3 - Severe limitation (flexion 30°-34°, extension 45°-49°, lateral flexion 25°-29°, rotation 45°-49°)
• 4 - Very severe limitation (<30° flexion, <45° extension, <25° lateral flexion, <45° rotation) The total limitation score was calculated as the sum of all six movement scores, with higher scores indicating greater cervical movement restriction.

Any adverse events such as local pain, swelling, dizziness, or fainting were observed and recorded after each treatment session. Severity and frequency were summarized descriptively.

Participants were allowed to take one 500 mg tablet of paracetamol at ≥6-hour intervals if the pain exceeded their tolerance, with a maximum dose of 1500 mg/day. The number of tablets used per day was recorded.