The aim of this work is to study the incidence of diaphragmatic dysfunction after COVID 19 infection and the efficacy of different types of diaphragmatic strengthening exercises on diaphragm muscle function.

Inclusion Criteria:

• Male and female above 18 years old
• history of probable or confirmed SARS-CoV-2 infection 3 months from the onset of symptoms or at least 2 months from the end of symptoms .

Exclusion Criteria:

• Subjects under 18.
• Patients known to have chronic lung disease .
• Patients known to have neuromuscular disorder.
• Patients known to have diaphragmatic hernia.
• Patients known to have malignancy.
• Patients with clinical evidence of phrenic nerve injury.
• Patients with recent abdominal or thoracic surgery,
• Patients with history of traumatic lesion possibly affecting diaphragm.
• Subjects with severe malnutrition.
• Patients with BMI more than 30