A randomized double blinded controlled trial will be conducted to determine and compare the effects of low and medium dose radial extracorporeal shock wave therapy on upper trapezius trigger points in patients with cervicogenic headache. Data will be collected at base line and at the end of the treatment program. Participants will be assigned randomly into three groups Group (A) will receive 2000 shock waves at frequency 10 MHz and 0.045 mj/mm2 flux density plus strengthening and stretching exercise for upper trapezius muscle.

Group (B) will receive 2000 shock waves at frequency 10 MHz and 0.18 mj/mm2 energy flux density plus strengthening and stretching exercise for upper trapezius muscle.

Group (C) will receive sham shock wave therapy plus strengthening and stretching exercise for upper trapezius muscle.

Inclusion Criteria:

• Symptoms of mechanical neck pain lasting for more than three months
• Skeletal muscle with a palpable taut band
• Hypersensitive point inside the taut band with the ability to reproduce referred pain when the sensitive spot is palpated,
• Joint soreness in at least one of the upper cervical spine's joints (c1-c3)
• Unilateral discomfort that originates in the neck and radiates to the frontotemporal area
• Pain that is made worse by moving the neck
• Headaches that occur at least once a week for a duration longer than three months.

Exclusion Criteria:

• Other primary headaches (i.e., migraine, tension-type headache)
• Bilateral headaches,
• Other defined cervical problem such as fracture, dislocation, skin disease, illness that is inflammatory, neural illness, vertebrobasilar insufficiency, a birth defect, tumor, or infection.