Effectiveness of proprioceptive neuromuscular facilitation and stabilization exercises on cross sectional area of deep flexor muscles in chronic non-specific neck pain

INTERVENTION: Intervention 1: Stability group: Patient will train stability exercises of neck and shoulder for 8 weeks. Intervention 2: PNF group: In this group, patients will train proprioceptive neuromuscular facilitation exercises of neck and upper limbs daily for 8 weeks. PNF group: In this group, patients will train proprioceptive neuromuscular facilitation exercises of neck and upper limbs daily for 8 weeks. Rehabilitation Stability group: Patient will train stability exercises of neck and shoulder for 8 weeks. CONDITION: Chronic neck pain. ; Soft tissue disorder, unspecified Soft tissue disorder, unspecified PRIMARY OUTCOME: Cross‐sectional area of deep neck flexor. Timepoint: Before intervention and 2 months after intervention. Method of measurement: By ultrasonography and per square centimeter. SECONDARY OUTCOME: Neck Disability Index. Timepoint: Before intervention and 2 months after intervention. Method of measurement: Neck Disability Index questionnaire. Pain. Timepoint: Before intervention and 2 months after intervention. Method of measurement: Visual Analog Scale questionnaire. INCLUSION CRITERIA: INCLUSION CRITERIA: Men and women; Aged 20 to 50 years; With chronic non‐specific neck pain; With BMI between 25 to 30. Exclusion criteria: Protrusion or Prolapse of disc with neurologic symptoms; Spinal surgery; Existence of certain structural damage in the neck; Neck pain caused by autoimmune diseases; Inflammation; Congenital deformity of spine; Compression fracture because of Osteoporosis; Stenosis and Spondylolysis or Spondylolisthesis; Myofacial Trigger Point; Shoulder injury; Rheumatoid arthritis; Pregnancy; Torticollis; Diabetes; Lung diseases; Myopathies; Cancer; History of physical therapy intervention on neck or shoulder in last three months; Physiotherapy; Chiropractic treatment; Osteopathy; Massage and so on to the neck or shoulders in the last three months.