While the results of the use of TENS, an electrotherapy method, in chronic neck pain are included in some studies, the evidence regarding the effects of diadynamic currents is quite limited.

While the results of the use of TENS, an electrotherapy method, in chronic neck pain are included in some studies, the evidence regarding the effects of diadynamic currents is quite limited.

TENS will be applied paravertebrally using four electrodes in the neck and back areas. Self-adhesive electrodes specific to each participant will be used for the application. TENS will run on symmetrical biphasic current at 100 Hz and 120 microseconds. The current intensity is determined by the level at which the person perceives the current. The participants are informed that they will get a current, which may induce a pins-and-needles sensation. It is essential for them to perceive the current distinctly; the intensity should be sufficient to be sensed without causing discomfort. The duration of the treatment is 20 minutes. Participants will receive exercises to strengthen the muscles around the neck.

All participants will receive treatment once a day, five days a week. A total of 15 sessions will be conducted over a duration of 3 weeks.

Visual Analog Scale will be used to assess pain intensity.

Visual Analog Scale Participants will be instructed to indicate their average pain intensity during rest, activity, and sleep on a 10-centimeter (cm) line, where 0 represents no pain and 10 represents horrible pain. The distance from the origin to the participant-marked point will be measured using a ruler, and pre-treatment pain scores will be recorded.

The Neck Disability Index is a scale that shows the functional status of the participants. The Neck Disability Index consists of ten questions related to pain intensity, personal care, lifting, reading, concentration, headaches, working, driving, sleeping, and recreational activities. For each question, there are 6 options ranging from 0 to 5 points. The questionnaire is evaluated out of a maximum of 50 points. "0 points" means no restrictions; "50 points' means full disability. "0-4 points" means no restriction, "5-14 points' means slightly restricted, "14-24 points' means moderately restricted, "25-34 points' means severely restricted, and "35 and above' means completely restricted.

McGill Pain Questionnaire- Short Form will be used to assess the overall pain of participants.

McGill Pain Questionnaire- Short Form The McGill Pain Questionnaire Short Form is sufficiently sensitive to determine the efficacy of treatment interventions in alleviating pain. The questionnaire comprises 15 characteristics evaluated on a 4-point scale (the initial 11 evaluate the kind of pain, while the final 4 measure the emotional dimension): 0 = none, 1 = mild, 2 = moderate, 3 = severe.