The aim of our study is to compare the short-term effects of traditional classical massage and percussive massage on neck pain, patient satisfaction level, and upper extremity flexibility in young adults with MBS. Another aim of the study is to contribute to the literature, as there are a limited number of studies that directly evaluate the effectiveness of popular vibration devices (Theragun, etc.) compared to classical massage. Original value: With the development of technology and the increase in mobile device usage times, MBS is increasingly common, especially among young adults and university students. There are limited studies in the literature on the treatment of MBS. No studies comparing the acute effects of classical massage and percussion therapy in the treatment of this syndrome have been found. Therefore, our study has the potential to make a unique contribution to the literature by offering a direct comparison between both traditional classical massage and the modern technological method of percussion gun.

Sociodemographic Assessment Form: The form to be prepared before the study will record information such as age (years), gender, body weight (kg) and height (cm) of the participants, as well as trauma-surgery history, systemic problems, and average daily mobile device usage time. Six symptoms reporting MBS diagnostic criteria (neck pain, back pain, shoulder pain, headache, insomnia, tingling and numbness in the hands) will be questioned .

Pain Assessment: The pain intensity of individuals with MBS will be assessed using the Visual Analog Scale, which is reported to be valid and reliable. Individuals included in the study will be asked to indicate the pain intensity they experienced in the last week on a vertically positioned 100 mm long line. The marked points will be measured and recorded in millimeters.

Neck Disability Index (NDI): It is planned to use the Neck Disability Index, which has Turkish validity and reliability, to determine neck disability. The first four items of the ten-item questionnaire are related to subjective symptoms, while the other six items are related to daily life activities. When the total score of the questionnaire is examined, 0 points indicate no disability, 5-14 points indicate mild disability, 15-24 points indicate moderate disability, 25-34 points indicate severe disability, and 35 points and above indicate complete disability.

Evaluation of Patient Satisfaction Level: The treatment satisfaction levels of the participants included in the study will be evaluated with the Patient Satisfaction Scale developed for physical therapy outpatient clinics.

The Turkish validity and reliability study of this 24-item scale was carried out by Tüzün et al. (2009) (Cronbach alpha: 0.88). The scale is scored between 0 (strongly disagree) and 4 (strongly agree), and higher scores indicate higher satisfaction. Assessment of Upper Extremity Balance: Participants' upper extremity balance and performance will be assessed using the Upper Extremity Balance Test.

While maintaining a push-up position with feet no more than twelve inches (30.5 cm) apart, the individual will reach with maximum effort in three directions (medial, superolateral, and inferolateral) with their free hand relative to the fixed hand, and the distance reached in each direction will be recorded. Each individual will be allowed to make 3 practice trials before the test, and the average of 3 trials will be used for analysis.

Assessment of Upper Extremity Flexibility: To assess the upper extremity flexibility of the participants, the Apley Scratch Test will be used. Also called the Dawbarn Test, the Apley Scratch Test provides a rapid assessment of the patient's active range of motion, including internal rotation, extension, and adduction. During the Apley scratch test, the patient attempts to reach upwards from their back, starting from below and aiming to place their hand between their shoulder blades. Then the distance between the two hands is measured with the help of a tape measure.

Interventions Percussive Massage Therapy: Percussive massage therapy will be applied with the TheraGun Relief Navy massage gun, which is planned to be supplied within the scope of the project. Percussive massage application will be applied from distal to proximal along the starting points of the trapezius, levator scapulae and cervical paravertebral muscles at a medium speed (level 2, range: 33-40 Hz) and 12 mm amplitude. Percussive therapy will be performed using the soft head of the massage gun with a treatment time of five minutes for each muscle group.

Classic Massage Therapy: After carefully protecting patient privacy in a prone position, general stroking is applied to the neck area, followed by massage oil using the 3 Stroking-3 Kneading-3 Stroking technique on the erector spinae, trapezius and levator scapulae muscles, from distal to proximal.

Inclusion Criteria:

• University students aged between 18 and 30 years.
• Willing to participate in the study and provide informed consent.
• Have been using a mobile device for at least 1 year.
• Have no communication impairments.
• Use a mobile device for at least 3 hours per day.
• Report at least three of the six core symptoms of Mobile Neck Syndrome (MNS): neck pain, upper back pain, shoulder pain, headache, insomnia, and tingling or numbness in the hands.
• Have a Neck Disability Index (NDI) score of 10 or higher.

Exclusion Criteria:

• History of generalized joint disorders affecting the head, neck, or shoulder region.
• History of radiotherapy involving the head, neck, or shoulder region.
• History of surgery involving the head or neck region.
• Diagnosis of cervical disc herniation, cervical radiculopathy, or cervical myelopathy.
• History of inflammatory, neuromuscular, or congenital disorders affecting the head or neck region.
• Presence of a metal implant in the treatment area.
• Current use of analgesics, muscle relaxants, anticoagulants, or other medications that may influence the study outcomes.
• History of systemic disease.
• Receipt of any treatment targeting the cervical region within the previous 3 months.
• Pregnancy.