The protocol for this group is identical to the previous group with the sole difference that is added an exercise protocol :

In the fifth session we explained the patients to perform :

• Five sets of isometric contraction of the deep neck flexors for 8-10 seconds.
• Five sets of isometric contraction of the neck extensors for 6-8 seconds
• Neural self-mobilization and stretching held for 10 - 12 seconds for the levator scapulae and the trapezius muscle.

In the sixth session the patient repeat all the exercises from the previous session and also with the help of a theraband made :

• Isotonic contraction of the head, performing 3-4 sets of 8-10 repetitions.

The protocol used for therapeutic education consisted of two approaches:

Manual therapy will consist on Traction oscillatory,craniocervical region, Mobilization of upper cervical region in flexion, Side glide roll, Mobilization upper cervical anteroposterior with Wedge, Sliding lateral techniques and High-velocity technique in dorsal region. And Education of the physiology of pain and Education about cognitive behavioral perspective.

Manual therapy will consist on Traction oscillatory, Mobilization of upper cervical region in flexion, Side glide roll, Mobilization upper cervical anteroposterior with Wedge, Sliding lateral C1- C2 ( 2 minutes) , C2 -C3, and C5 -C6 and High-velocity technique in dorsal region.

Manual therapy will consist on Traction oscillatory,craniocervical region, Mobilization of upper cervical region in flexion, Side glide roll, Mobilization upper cervical anteroposterior with Wedge, Sliding lateral techniques and High-velocity technique in dorsal region. And Education of the physiology of pain and Education about cognitive behavioral perspective will add to manual therapy treatment.

This scale comprises of a 100-mm horizontal line with pain descriptors marked "no pain" at left side and "the worst pain imagine" at the right side, and is used to measure the pain intensity. It was recorded at the beginning of the physical assessment and the patient was asked what their pain intensity was at the time by marking the VAS with a perpendicular line. This is a valid method to measure the pain level37 and psychometric properties of the VAS have been reported widely. The minimal important difference of the VAS is based on detecting an 8.6 mm (based in previous study for a score < 40mm with a pain onset more than 12 weeks) of difference immediately after treatment.

Pressure pain threshold (PPT) is defined as the amount of pressure where the sense of pressure first changes to pain. A digital algometer (FDX 25, Wagner Instruments, CT, USA), will be used. Pressure pain threshold was assessed over right side of masseter 1 and 2, the temporalis muscle 1 and 2, suboccipital muscle, spinous process of C2, vertebral joint process of C5 y C6, upper trapezius muscle (midway between C7 and acromion), epicondyle, scaphoid bone and tibialis anterior muscle (upper one-third of the muscle belly) by an assessor blinded to the subject's condition.

Cervical spine mobility was measured with Cervical Range of Motion (CROM) device (Performance Attainment Associates, MN). The CROM is an instrument that assesses the active range of motion of the cervical segment. It´s a reliable method of measuring, providing a range of intra-meter reliability from 0.7 to 0.9 and a range of inter-meter reliability from 0.8 to 0.87. The patients were measured while sitting with the back against a chair. The goniometer placed over his head, is asked to perform analytical neck movements (flexion, extension, right lateral flexion, left lateral flexion, right rotation and left rotation).

The Tampa Scale for Kinesiophobia, developed by Miller was used to assess fear of movement and injury. We used a 11-items version.