what causes my arm to be weak when lifting something
Functional weakness is weakness of an arm or leg due to the nervous system not working properly. It is not caused by damage or disease of the nervous system. Patients with functional weakness experience symptoms of limb weakness which can be disabling and frightening such as problems walking or a âheavinessâ down one side, dropping things or a feeling that a limb just doesnât feel normal or âpart of themâ.