This prospective, single-blind, parallel-group randomized controlled trial evaluated whether adding cervical and thoracic spinal mobilization (Maitland concept, grades I-IV) to a structured home therapeutic exercise program improves pain intensity and physical fitness parameters in recreational tennis players with mechanical neck pain. Thirty adults aged 18-45 years with body mass index (BMI) of 18-30 kg/m² and mechanical neck pain (Visual Analog Scale, VAS > 4) lasting more than one week were randomized 1:1 into a Control Group (CG, n=15) performing an unsupervised 21-session home exercise program (one session per day for three weeks) and an Experimental Group (EG, n=15) performing the identical home exercise program plus four therapist-delivered sessions of cervical and upper thoracic spinal mobilization (one at baseline and one per week thereafter, across three weeks). Outcomes assessed at baseline (Week 0) and post-intervention (Week 3) included VAS for pain during physical activity, at rest, and during sleep; cervical range of motion measured with a Cervical Range of Motion (CROM) device; isometric neck muscle strength (handheld dynamometer); pinch and hand grip strength; ruler-drop reaction time; sit-and-reach flexibility; and vertical jump performance assessed with the My Jump Lab application.

Design: Prospective, single-blind, randomized controlled, two-arm parallel-group superiority trial. Eligible adults aged 18-45 years (BMI 18-30 kg/m²) who were recreational tennis players (playing tennis at least twice weekly, ≥2 hours/week) and presented with mechanical neck pain (>1 week duration, VAS > 4, reduced cervical range of motion confirmed by the cervical flexion-rotation test, and tenderness on external pressure over at least one cervical joint) were enrolled after providing written informed consent. Participants were allocated 1:1 to one of two groups using simple randomization with sealed opaque envelopes. The outcome assessor was blinded to group allocation (single-blind, assessor masking).

Interventions: Both groups completed an identical structured home exercise program lasting three weeks (21 daily sessions). The program comprised stretching of the upper trapezius, right and left levator scapulae, hamstring, and lumbar extensor muscles (30-second holds, 5 repetitions, 3 sets), isometric resistance exercises for cervical flexion, extension, and right and left lateral flexion (10-second holds with 10-second rests, 5 repetitions, 3 sets), the chin-tuck exercise (10-second holds, 5 repetitions, 3 sets), and the cat-camel exercise (10-second holds in each position, 5 repetitions, 3 sets). Written instructions illustrated by figures were provided to ensure correct execution and adherence. The Experimental Group received the same home program plus a Maitland-concept spinal mobilization protocol delivered by a physiotherapist over four supervised sessions (one at baseline and one per week, total of four sessions across three weeks). Cervical mobilization was applied with the participant prone, the therapist standing at the head, and bilateral thumb pressure applied over the facet joint or spinous process of the targeted hypomobile vertebra; grades I-II were used when pain preceded the motion limit and grades III-IV when the motion limit preceded pain, with oscillations at 2-3 Hz performed for approximately 30 seconds per bout, 3-4 bouts per segment, with 1-minute rest between bouts. Upper thoracic mobilization aimed to increase upper-thoracic extension, applying the same dosage as the cervical mobilization, performed with anterior-to-posterior pressure on the transverse processes of the targeted segments.

Assessments: Pre-intervention (Week 0) and post-intervention (Week 3) measurements were performed in a fixed order with rest intervals. Pain intensity was assessed using a 10 cm Visual Analog Scale (VAS) for pain during physical activity, at rest, and during sleep. Cervical active range of motion (flexion, extension, right and left lateral flexion, right and left rotation) was measured with a Cervical Range of Motion (CROM) device with the participant in upright sitting (three measurements per direction, recorded in degrees). Isometric neck muscle strength for flexion, extension, and bilateral lateral flexion was measured using a handheld dynamometer (JTECH Medical Commander Echo MMT) with the participant seated; the maximum of three 3-second contractions was averaged and recorded in kilograms-force. Hand grip strength (hydraulic hand dynamometer) and pinch grip strength (pinch meter) were measured bilaterally in standardized seated posture with elbow at 90° flexion (mean of three trials, kilograms). Reaction time was assessed bilaterally using the Ruler Drop Test with a 60 cm ruler. Vertical jump height was measured using the validated My Jump Lab smartphone application (iPhone 15 Pro Max on a tripod 20 cm above the floor), with three trials and the highest, lowest, and mean values recorded. Flexibility was measured by the sit-and-reach test (three trials, recorded in centimeters).

Statistical Analysis: Sample size of 30 (15 per group) was based on study termination criteria. Descriptive statistics included mean ± standard deviation, median with 25th-75th percentiles, and frequencies. Normality was tested with the Shapiro-Wilk test. Within-group changes were analyzed using paired-samples t-tests for normally distributed variables and the Wilcoxon signed-rank test for non-normally distributed variables; between-group comparisons of change scores used independent-samples t-tests or the Mann-Whitney U test as appropriate. Categorical variables were compared using chi-square tests. Statistical significance was set at p < 0.05. Analyses were performed in IBM SPSS Statistics. There was no external funding for this study and the investigators declare no conflicts of interest.

Inclusion Criteria:

• Age between 18 and 45 years.
• Body Mass Index (BMI) between 18 and 30 kg/m².
• Recreational tennis player, playing tennis at least 2 days per week and at least 2 hours per week.
• Mechanical neck pain triggered by neck movement or sustained positions on the symptomatic side.
• Reduced cervical range of motion as confirmed by a positive cervical flexion-rotation test.
• Pain elicited by external pressure over at least one cervical zygapophyseal (facet) joint.
• Neck pain of at least 1 week duration, with intensity greater than 4/10 on the Visual Analog Scale (VAS), not associated with any specific medical history.
• Able to communicate in Turkish or English (verbal and written).
• Free from systemic, orthopedic, neurological, chronic, or psychiatric disease.

Exclusion Criteria:

• Neck pain of more than 6 months duration.
• Concomitant sensory loss (paresthesia, hypoesthesia, or anesthesia).
• Pain radiating to the upper extremities (radicular symptoms).
• History of long-term systemic corticosteroid use.
• Regular use of medications affecting musculoskeletal performance or pain perception.
• Sequelae from prior injury or any surgical history involving the cervical or thoracic spine.
• Prior interventional procedures targeting the neck region (e.g., injection therapy).
• Pregnancy or suspected pregnancy.
• During the study: pain greater than 3/10 on VAS during sessions, three consecutive missed sessions, incident illness or trauma, withdrawal request, or failure to meet exercise progression criteria.

Single (Outcomes Assessor). The outcome assessor performing baseline and post-intervention measurements was blinded to group allocation; participants and the treating physiotherapist were not blinded due to the nature of the manual therapy intervention