The goal of this clinical trial study: is to determine the effect of Virtual reality on pain and function for shoulder dysfunction post neck dissection surgeries. The main question is: Can Virtual reality technique affect the dysfunction of shoulder joint post neck dissection surgeries? Participants will receive the treatment for 2 times per week for 2 months. Assessment will be done before and after treatment.

1. Subjects: sixty eight patients from both genders, suffering from shoulder dysfunction post neck dissection surgery, their ages ranges from 40-60 years.
2. Design of the study:

In this study the patients will be randomly assigned into two equal groups (34 patients for each group):

1. Group A (Study group):

   This group includes 34 patients suffering from pain and loss of shoulder flexion, abduction and external rotation ROM, patients will be treated with active ROM exercise, stretching exercise for shoulder extensors, adductors and internal rotators muscles and strengthening exercise for shoulder muscles, and with fully immersive Head-Mounted Display virtual reality (Oculus Quest virtual reality (VR) headset with hand controller) for 30 min. 2 times per week for 2 months.

2. Group B (Control group):

This group includes 34 patients suffering from pain and loss of shoulder flexion, abduction and external rotation ROM, patients will be treated with traditional physical therapy: active ROM exercise, stretching exercise for shoulder extensors, adductors and internal rotators muscles and strengthening exercise for shoulder muscles, 2 times per week for 2 months.

- Equipments:

Measuring tools:

• Measuring and assessment of pain by: Smart phone version of visual analogue scale (VAS).
• Measuring range of motion (ROM) by: Mobile application Goniometer.
• Measuring upper limb function by: The Arabic Version of Modified QuickDASH-9 Questionnaire.

Therapeutic equipment:

• Oculus Quest virtual reality (VR) headset with hand controller.

Each patient will play 3 games 10 min. for each with 1 min. rest in between. First game is Dance loop gameplay, there are throwing balls moving toward the patient in all directions, and the patient tries to catch all of them by the arm controllers, so it promote the movement of the arm toward flexion, abduction and external rotation directions.

Second game is Tennis ball, which promote the arm to move toward flexion, abduction and external rotation directions.

Third game is Boxing, which promote the arm to move toward flexion and abduction directions.

Inclusion Criteria:

• Age range between 40-60 years
• Both genders will participate in the study
• All patients have undergone neck dissection surgery
• All patients enrolled to the study will have their informed consent

Exclusion Criteria:

• Age more than 60 years or less than 40 years
• Subjects who have hearing problems
• Subjects who have visual problems
• Patients have acute viral diseases, acute tuberculosis, mental disorders or those with pace makers