I've been experiencing a strong jerk/twitch in my latissimus muscle couple times a day for the past 5-6 months. should i be concerned?

Muscle spasm: Causes may include repetitive use, persistent postural stress, or an underlying structural problem. The lats commonly develop knots caused by injury, overuse, or a sedentary lifestyle. The knots are a result of tense muscle tissue that is stuck in a spasm-like state. If the spams persist, see your physician. http://www.nlm.nih.gov/medlineplus/ency/patientinstructions/000063.htm

Fasciculation: A brief contraction of a bundle of muscle fibers is normally a fasciculation. It is no cause for concern. Weakness, reduced muscle bulk and pain are important symptoms though.