The study will compare the effect of virtual reality based exercise training versus Mulligan mobilization in addition to exercise therapy added to both groups on shoulder posture and function in subacromial impingement syndrome.

Inclusion Criteria:

• Patients will be referred from the orthopedic surgeon with a diagnosis of stage II SIS with the following criteria:

  1. Participants ranged in age from 30-50 years old.
  2. Participants are from non-athletes from the general population.
  3. Unilateral shoulder pain that is localized either anteriorly or laterally to the acromion. Pain that occurs or worsens when the affected shoulder is in flexion and/or abduction.
  4. Four of the following should be present in the included patients: Neer impingement test, Hawkins' test, Pain was replicated in the supraspinatus empty-can test, a painful arc of movement from 70° to 120°, and painful greater tuberosity of the humerus.
  5. BMI range 18.5- 29.9 Kg/m².

Exclusion Criteria:

• 1) Patients who, during the previous three months, underwent shoulder physical treatment and/or an acute pain flare.

  2) Patients who have undergone surgeries for tendon repair. 3) Malignancy, epilepsy, pregnant women, and/or systemic conditions like chronic renal or liver failure.

  4) Mini-Mental State Examination test (MMSE) (< 24/30) to exclude cognitive impairment and/or significant vision impairment (if they couldn't read the introduction while wearing the Head Mounted Device (HMD).

  5) Corticosteroid injection during the last three months or used steroids chronically.

  6) Adhesive capsulitis, glenohumeral joint instability, Numbness or tingling of the upper limb, and/or full-thickness tear of the rotator cuff.