Literature review Delayed onset muscle soreness (DOMS), or what is commonly known as post-exercise muscle soreness, is the feeling of discomfort and pain muscle (Lieber and Friden, 2002) which are caused by vigorous and unusual resistance training or any form of muscular effort (Kisner and Colby, 2012). Other commonly observed symptoms are loss of strength and range of motion (ROM) (Valle et.at. 2013). These symptoms of DOMS usually begin to be experienced about 12 to 24 hours after exercise and usually last a few days, but have been known to last 10 to 14 days. Much research has been done on various aspects of DOMS, what causes it, how to prevent it, and how to treat it once it occurs in an athlete. But unfortunately, very little is known about DOMS. Throughout this section, many aspects of DOMS will be examined. First, there will be an introduction to the etiology of DOMS and the many theories about why and how this phenomenon occurs. Second, measures taken to prevent DOMS will be discussed. Finally, there are many different approaches to treating an athlete with DOMS, with most of the actual benefits of these treatments being inconclusive at best, and even detrimental in some cases. Possible Causes of DOMSMuscle Spasm TheoryOne theory thought to be the cause of DOMS in the 1960s was the muscle spasm theory. This theory suggested that a pain feedback cycle caused by ischemia and an accumulation of metabolic waste during exercise led to muscle spasms (Kisner & Colby, 2012). It was hypothesized that the accumulation of these metabolic wastes caused the symptoms of DOMS and a continuous pain-spasm reflex cycle that could last for several days afterwards (Vries, 1966). This theory has since been dispelled in the middle of the article ......d on myofibril damage in human muscles with DOMS: an ultrastructural and immunoelectron microscope study. Histochemistry and Cell Biology, 121(3), 219-227.Ayles, S., Graven-Nielsen, T., and Gibson, W. (2011). Vibration-induced afferent activity increases delayed onset muscle allodynia. The Journal of Pain, 12(8), 884-891. Vries, H. A. (1966). Quantitative electromyographic investigation of muscle pain spasm theory. American Journal of Physical Medicine and Rehabilitation, 45(3). Abraham, W. M. (1977). Factors of delayed muscle soreness. Medicine and Science in Sport and Exercise, 9(1), 11???20. Jakeman, J.R., Byrne, C., & Eston, RG (2010). Effectiveness of Lower Limb Compression and Combined Treatment of Manual Massage and Lower Limb Compression on Symptoms of Exercise-Induced Muscle Injury in Women. Journal of Strength and Conditioning Research, 24(11), 3157-3165.