muscle activation during maximum voluntary contraction and mwave related in healthy but not in injured conditions implications when normalizing electromyography background electromyography signal amplitude is influenced by a variety of factors normalization strategies aimed at decreasing signal variability include using peak electromyography signal during a maximum voluntary contraction and peaktopeak mwave amplitude however whether these normalization methods are comparable has not been investigated in injured populations this study investigated the relationship between peak signal during maximum voluntary contraction and mwave amplitude in individuals with a unilateral achilles tendon rupture secondarily we observed whether the two normalizations strategies would yield similar results when evaluating between limb differences in muscle activity during a jump taskmethods eleven individuals 13years after a unilateral achilles tendon rupture were included in this study surface electromyography was used on the medial and lateral gastrocnemii bilaterally peak maximum voluntary contraction mwave amplitude and electromyography during a jumping task were collectedfindings a strong relationship was observed between peak maximum voluntary contraction and mwave amplitude on the uninjured r071088 p005 the two normalization techniques did not produce different results when comparing the uninjured and ruptured sidesinterpretation the findings of this study suggest that mwave normalization yields similar results as peak maximum voluntary contractionnormalized electromyography in uninjured conditions mwave normalization may be a useful strategy in an injured population where a maximal muscle contraction is unsafe or impaired