The purpose of this study will investigate the effect of adding high power pain threshold ultrasound to traditional therapy on axioappendicular muscles amplitude and fatigue in neck pain

Myofascial pain syndrome is a common musculoskeletal pain disorder affecting almost 95% of people with chronic pain disorders and is a common finding in especially pain management centres.It is characterized by trigger points, defined as hyperirritable spots within taut bands of skeletal muscle fibers. The syndrome is associated with tenderness in the muscle, referred pain, spasm and restriction of motion. Patients with MPS begin with one active MTrP (called the primary MTrP) in the affected muscles due to chronic repetitive minor muscle strain, poor posture, systemic diseases, or neuro-musculoskeletal lesions. When not treated correctly, expansion of the pain region and additional active MTrPs (called secondary or satellite MTrPs) will develop one of the most appropriate treatments for trigger points ultrasound therapy. The high-power pain threshold ultrasound (HPPTUS) technique is one of the ultrasound modifications used to treat trigger points In 2004, Majlesi et al. performed the first clinical study to compare this technique with the traditional ultrasound technique in patients with myofascial trigger points. The results showed that HPPTUS was much more effective than the traditional technique, and pain reduction and improved range of motion (ROM) were significant in a smaller number of sessions.sixty patients with mechanical neck pain will be assigned randomly to two equal group. one group will receive high power pain threshold ultrasound and traditional therapy and the other receive traditional therapy alone for four weeks.

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Inclusion Criteria:

• patients with mechanical neck pain from both genders.
• age between 19 and 38 years
• patients will be required to have active TrPs in the upper trapezius and levator muscle and neck pain

Exclusion Criteria:

• Patients will be excluded if they have History of whiplash injury,
• History of cervical spine surgery,
• Cervical radiculopathy or myelopathy,
• Having undergone physical therapy within the past 3 months before the study
• Non- rheumatologic diseases as multiple sclerosis,
• thyroid dysfunction and chronic infection and Rheumatologic condition as mild systemic lupus erythematosus, poly-articular osteoarthritis, rheumatoid arthritis and advanced cervical spine degenerative diseases.

permuted block randomization