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Freebase(4.82 / 22 votes)Rate this definition: Muscle pain. Myalgia, or muscle pain, is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections.
What is a Muscle Strain. Definition of a muscle strain : A strain is an injury to a muscle or tendon in which the muscle fibres tear as a result of over-stretching. Remember a Strain is NOT a Sprain.You strain a muscle but you sprain a ligament.A muscle strain is also commonly known as a pulled muscle.efinition of a muscle strain : A strain is an injury to a muscle or tendon in which the muscle fibres tear as a result of over-stretching. Remember a Strain is NOT a Sprain.