Visual Analogue Scale (VAS)
Time frame · Baseline and Post-treatment (4 weeks)
A validated 10-centimeter scale used to evaluate the intensity of neck pain. The scale is anchored at 0 cm (representing "no pain") and 10 cm (representing the "worst imaginable pain"). Baseline severity is categorized as mild (≤ 3.4 cm), moderate (3.5-7.4 cm), and severe (≥7.5 cm). Higher scores indicate greater pain intensity. This metric serves both as a primary efficacy outcome and an inclusion criterion (≥3.5 cm).
Neck Disability Index (NDI)
Time frame · Baseline and Post-treatment (4 weeks)
The Turkish version of the Neck Disability Index (NDI), used to assess functional impairment related to neck pain. It comprises 10 items (including pain intensity, personal care, lifting, reading, headaches, concentration, work, driving, sleeping, and recreation). Each item is scored from 0 (no disability) to 5 (most severe disability), yielding a total cumulative score ranging from 0 to 50. Higher scores indicate greater functional impairment, categorized as no disability (0-4), mild (5-14), moderate (15-24), severe (25-34), and complete (≥ 35). The minimal clinically important difference (MCID) is 8.5 to 9.5 points. This scale serves as both a primary outcome and an inclusion criterion (≥ 5 points).
Cervical Range of Motion (CROM)
Time frame · Baseline and Post-treatment (4 weeks)
Active cervical ROM is assessed across three anatomical planes using the Baseline CROM Deluxe device, which utilizes two gravity-dependent goniometers and a head-mounted compass dial. Measured movements include cervical flexion, extension, right/left lateral flexion, and right/left rotation, recorded in degrees. The arithmetic mean of two consecutive trials for each movement is used for analysis. Higher values indicate greater joint mobility
Cervical Joint Position Sense (JPS)
Time frame · Baseline and Post-treatment (4 weeks)
Cervical joint position sense (JPS) is evaluated using the Baseline CROM Deluxe device to measure target repositioning accuracy. The target angle for each direction is set at 65% of the participant's mean maximum active ROM. The absolute error between the target angle and the participant's active repositioning attempt is recorded in degrees. Smaller error values indicate superior proprioceptive accuracy and joint position sense.
Postural Stability (Sway Medical Application)
Time frame · Baseline and Post-treatment (4 weeks)
Static postural stability is assessed using the Sway Medical mobile balance application via a triaxial accelerometer. The protocol involves 5 sequential static standing conditions performed on a firm surface while blindfolded: (1) feet together, (2) tandem stance with left foot forward, (3) tandem stance with right foot forward, (4) single-leg stance on the right, and (5) single-leg stance on the left. Balance scores are derived from deviance acceleration using proprietary algorithms. The application generates a composite score ranging from 0 to 100, where higher scores indicate superior postural control and balance.
Dynamic Balance (Y-Balance Test)
Time frame · Baseline and Post-treatment (4 weeks)
Dynamic balance is evaluated barefoot using the Y-Balance Test (YBT) in three reach directions: anterior, posterolateral, and posteromedial. Maximum reach distances are recorded after six practice trials and three formal trials per direction. Reach distances are normalized to the participant's leg length (measured from the anterior superior iliac spine to the medial malleolus) and expressed as a percentage (%). A composite score is calculated by averaging the normalized percentages across all three directions, with higher scores representing superior dynamic balance.
Cervical Deep Flexor Muscle Endurance
Time frame · Baseline and Post-treatment (4 weeks)
sometric endurance of the deep cervical flexor muscles is assessed using the Cervical Deep Flexor Endurance Test. Participants in a supine, hook-lying position execute a craniocervical flexion (chin-tuck) maneuver, elevate their head approximately 2.5 cm off the surface, and maintain this position for as long as possible. The duration is recorded in seconds (s) until termination criteria are met (e.g., loss of alignment, head contact with the surface, acute pain, or participant request). Longer holding times indicate better muscle endurance.
Gaze Stability (Head-Eye Movement Control Test)
Time frame · Baseline and Post-treatment (4 weeks)
Dynamic head-eye coordination and gaze stability are evaluated using the Head-Eye Movement Control Test. Participants maintain visual fixation on a camera lens during rapid, maximum-range head rotations. Performance is graded on an ordinal 3-point scale: 0 (stable gaze with coordinated movements), 1 (stable gaze with slightly uncoordinated movements), and 2 (recurrent gaze instability with slow, poorly controlled movements). Lower scores represent better gaze stability and motor control.