The main symptoms of patients with muscle diseases are weakness, which is usually progressive, bilateral and often involves muscles close to the body such as pelvic and shoulder muscles. The patient may be aware of difficulties in walking or running, climbing stairs, getting up from a seat, lifting heavy weights, lifting or grabbing over the shoulders. In infants and young children, this weakness may appear as loss of voice, too late to stand, walk or run. Often, weakness is associated with muscle weakness. Although muscle and muscle aches may occur in muscle diseases, these symptoms are more common from other causes such as muscle tension. Get tired of the weakness commonly associated with myasthenia gravis. Episodic paralysis is a special symptom of periodic paralysis.
Source : https://www.singhealth.com.sg/PatientCare/Overseas-Referral/bh/Conditions/Pages/Muscle-Diseases.aspx