the aim of this study is to investigate if there is any difference between INSTRUMENT-ASSISTED SOFT TISSUE MOBILIZATION and Muscle Energy Technique over sternocleidomastoid on Neck pain, Range of motion and Functional disability in patients with Chronic Non-specific Neck Pain

Non-specific neck pain (NSNP) is the most common and the 4th leading cause of musculoskeletal disorder worldwide. It is estimated that about 70% of the population experiences neck pain throughout life, with an annual incidence of 15% to 50%0. It is seen more commonly in middle-aged females. It has been well established that NSNP is not only the risk factor for developing severe spinal pathologies and functional disability but that it is also associated with decreasing the quality of life and productivity of workers. Pain, which leads to functional limitations especially in the cervical region, is associated with a decrease in the activation of the deep cervical flexors such as the longus colli and longus capitis muscles, and an increase in the activation of the superficial cervical flexors, such as SCM and anterior scalene muscles.It is reported that in individuals with CNP, there is an increase in the activation of SCM and anterior scalene muscles, especially during isometric cervical flexion and dynamic upper limb movements. In their study, Falla et al. concluded that individuals with unilateral CNP had muscle fatigue in their ipsilateral SCM and anterior scalene muscles. Wang et al. reported postural imbalance in individuals with CNP due to an increased activation and tightening of the suboccipital, SCM, upper trapezius, pectoralis, and rotator cuff muscles. A study by Mostafa et al., (2021) stated that IASTM has a favorable effect than conventional treatment in reduction mechanical neck pain, improvement cervical range of motion &activity of daily living.

A Systematic Review by Sbardella et al., (2021) stated that all the studies analyzed show an effective improvement in the outcomes of pain, disability and joint function, which leads us to say that Muscle Energy Technique (MET) is certainly an effective and safe technique in the treatment of cervical pain.

this trail has three groups; one will receive IASTM+ conventional, the second will receive Muscle energy technique+ conventional and the third one will receive conventional treatment for four weeks

Inclusion Criteria:

1. The subjects are of both genders, aged between 18-35 years old .
2. Subjects with Neck pain continued for at least the last 12 weeks .
3. body mass index (18.5-24.9).

Exclusion Criteria:

1. Any specific neck pathology as radiculopathy, rheumatoid arthritis, and systemic diseases
2. Sensory problems at the mid or upper back .
3. A tendency to hemorrhage or anticoagulation treatment. And nonsteroidal pain medication .
4. Signs of severe pathology such as malignancy, fractures of the cervical spine, cervical radiculopathy or myelopathy, or vascular syndromes such as vertebrobasilar insufficiency .
5. surgery of the cervical spine, whiplash trauma (in the past or recent, as cause of the complaint).