Participants will perform three DNS exercise positions based on their ability: the 3-month prone developmental position, the 6-month developmental position, and the quadruped position. Each position will be done 3-6 repetitions and actively held for 30 to 60 seconds. Participants will perform both exercises at home twice daily, adjusting based on their ability and ensuring they do not experience pain.

Participants will perform two types of exercises: Deep Cervical Flexor Training and Deep Cervical Extensor Training. For flexor training, they will lie on their back with a small towel under the suboccipital region and slowly move their head to the inner range. This will be done in sets of 10 repetitions with a 30-second rest between sets. For extensor training, they will sit upright with their hands folded below the occiput, pushing into extension against their hands and holding the posture as long as possible. This exercise consists of 3 sets of 6 repetitions, with a 6-second rest between repetitions and a 30-seconds break between sets. Participants will perform both exercises at home twice in 6 days a week, adjusting based on their ability and ensuring they do not experience pain.

DNS is a method used to enhance muscle stability. It is a manual and rehabilitative approach based on developmental kinesiology to optimize the movement system. These exercises optimize internal muscle forces on each spinal segment.

All participants will be conducted a standard MRI of the cervical spine. They will be asked to lie on their backs and maintain a neutral cervical spine position without rotation, lateral flexion, or exaggerated lordosis. A neck coil will be used during the examination to enhance imaging accuracy. MRI will be performed using the SIGNA Premier 3.OT (GE Healthcare Japan) (Repetition time, 8000 ms; Excitation time, 102 ms; Voxel size, 0.4 x 0.4 mm; Field of view, 200 x 200 mm; Thickness, 3.5 mm). Specific neck muscles (Longus Colli + capitis, Multifidus, Semispinalis cervicis, Semispinalis capitis, and Splenius capitis + cervicis) will be mapped and analyzed for fatty infiltration using Miele-lxiv image processing software. The total fatty infiltration for bilateral muscles at different levels in the neck will be calculated.

The Neck Disability Index (NDI) is a 10-question survey that measures how neck pain affects daily life. The patient rates their pain intensity, headaches, and difficulty with personal care, lifting, reading, concentration, work, driving, sleeping, and recreation. A change of 5%-10% is considered meaningful.

Shisei-Karte is a Japanese AI-based website that analyzes posture using images. It assesses head posture, including forward and backward tilts and misalignment. The goal is to detect issues like forward head posture. The process has three steps: (1) participants register with basic details, (2) a side-view photo is taken, and (3) the AI analyzes and displays results in about 30 seconds.