The study is a Prospective, Randomized, Single-blinded, Sham device controlled, Parallel Treatment Grouped, Multi-center, Exploratory Clinical Trial to Evaluate Improvement of Cervical Lordosis and Safety of CGM MB-1701 (Spinal warm massage device, Ceragem Master V6) in Subjects with Cervical Kyphosis and Posterior Neck Pain.

The Cervical Kyphosis are also commonly referred to as "turtle neck syndrome." It refers to the deformation of the neck bone into an inverted C-shape due to abnormalities or degenerative changes, and it is named to mean that the neck is bent like a turtle.

This device, Ceragem Master V6 (CGM MB-1701), has been certified as a combination of a personal warmer that can be used to relieve muscle pain by applying constant heat to the human body and a medical vibrator of a device that applies physical energy (vibration, shock, pressure, etc.). Also, the device got approval for use with intermittent pneumatic compression and electrically-powered orthopedics traction.

The primary purpose of this clinical trial is to confirm the temporary cervical lordosis angle improvement (height) in subjects with cervical kyphosis through the combined function of the test device.

Inclusion Criteria:

1. Adult male and female subjects who have voluntarily decided to participate and agreed in writing after being briefed on the characteristics of this clinical trial and medical device
2. Subjects with cervical kyphosis angle between cervical lordosis 20 degrees and cervical kyphosis 5 degrees.
3. BMI betweeen 18.5 and 30
4. Chronic neck pain NRS 4 or higher lasting more than 3 months

Exclusion Criteria:

1. Secondary spondylosis
2. A tumor of the spine
3. Inflammatory spondylitis
4. Myelopathy
5. Multiple adjacent radiculopathies and others