What can cause a person feeling weak and shaking arms after the corona virus, no fever for 4 days originally had fever for 13 days now weakness and shaking hands like tremor?

Mechanism unsure: Coronavirus (COVID 19) is a new infection and much is not known about how it causes complications. We do know it can affect multiple organ systems eg the lungs, muscles (causing fatigue), the heart (heart attacks), the liver, the kidneys and the brain. There are reports of patients with seizures, tremors, altered mental status, loss of taste and smell, headache, strokes and extremity numbness.

Residual effects: There is a lot we still need to learn about this virus. Many people who have had more significant illness have slow recovery with residual symptoms.