IMPORTANCE Coronavirus disease MESHD 2019 (COVID-19) is an emerging disease MESHD that was declared as a pandemic by WHO. Although there are many retrospective studies to present clinical aspects of the COVID-19, still the involvement of the musculoskeletal system has not been deeply investigated.OBJECTIVE To classify the symptoms of musculoskeletal system in COVID-19 patients, to evaluate myalgia MESHD myalgia HP, arthralgia MESHD arthralgia HP and physical/ mental fatigue MESHD fatigue HP, to assess handgrip muscle strength, and to examine the relationship of these parameters with the severity and laboratory values of the disease MESHD. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study was performed at the IUC-Cerrahpaşa Pandemic Clinic. Hospitalized 150 adults TRANS with laboratory and radiological confirmation of severe acute respiratory syndrome MESHD coronavirus 2 (SARS-CoV-2) according to WHO interim guidance were included in the study. Data were recorded from May 15,2020, to June 30, 2020.MAIN OUTCOMES AND MEASURES Demographic data, comorbidities, musculoskeletal symptoms, laboratory findings and CT scans were recorded. To determine the disease MESHD severity 2007 idsa/ats guidelines for community acquired pneumonia MESHD pneumonia HP was used. Myalgia MESHD Myalgia HP severity was calculated by numerical rating scale (NRS). Visual analog scale and Chalder Fatigue MESHD Fatigue HP Scale (CFS) were used for fatigue MESHD fatigue HP severity determination. Handgrip strength (HGS) was measured by Jamar hand dynamometer.RESULTS 103 patients (68.7%) were nonsevere and 47 patients (31.3%) were severe. The most common musculoskeletal symptom was fatigue MESHD fatigue HP (133 [85.3%]), followed by myalgia MESHD myalgia HP (102 [68.0%]), arthralgia MESHD arthralgia HP (65 [43.3%]) and back pain MESHD back pain HP (33 [22.0%]). Arthralgia MESHD Arthralgia HP, which was mostly notable at wrist (25 [16.7%]), ankle (24 [16.0%]) and knee (23 [15.3%]) joints, showed significant correlation with disease MESHD severity. There was severe myalgia MESHD myalgia HP according to NRS regardless of disease MESHD severity. The physical fatigue MESHD fatigue HP severity score was significantly higher in severe cases, whereas no relationship was found with mental fatigue MESHD fatigue HP score. Female patients with severe infection HP infection MESHD had lower grip strength with a mean value of 18.26 kg (P= .010) in dominant hand, whereas no relationship was found between disease MESHD severity and grip strength in male TRANS patients, but the mean values in both genders TRANS and in decades appears below the specified normative values. Lactate dehydrogenase (LDH) level and lymphocyte count were significantly correlated with lower grip strength. LDH, C-reactive protein (CRP) and D-dimer levels were above the normal range in patients with myalgia MESHD myalgia HP, arthralgia MESHD arthralgia HP and fatigue MESHD fatigue HP. CONCLUSIONS AND RELEVANCE Musculoskeletal symptoms are quite common aside from other multi-systemic symptoms in patients with COVID-19. Arthralgia MESHD Arthralgia HP, which is related to the disease MESHD severity, should be considered apart from myalgia MESHD myalgia HP. COVID-19 patients have severe ischemic myalgia MESHD myalgia HP regardless of the disease MESHD activity. Although there is a muscle weakness MESHD muscle weakness HP in all patients, the loss of muscle function is related with the disease MESHD activity especially in women. Muscular involvement in coronavirus disease MESHD is a triangle of myalgia MESHD myalgia HP, physical fatigue MESHD fatigue HP, and functional impairment.