Conclusion Overall , our findings do not support the presence of a secondary loss of strength following an acute muscle injury , and strongly suggest that strength , on average , recovers steadily over the first 3 days post-injury
Background An immediate loss of strength follows virtually all types of muscle injury but there is debate whether the initial strength loss is maximal or if a secondary loss of strength occurs during the first 3 days post-injury .
Objective The objective of this analysis was to conduct a systematic review and meta- analysis of the research literature to determine if a secondary loss of strength occurs after an injurious initiating event .
Weakness in Mouse Masticatory Muscles by Repetitive Contractions with Forced Lengthening
The etiology of myofascial tenderness and pain of masticatory muscles in humans is difficult to underst and . Parafunctional oral habits such as tooth grinding or vigorous chewing are thought to be factors . The objective of this study was to determine if masticatory muscles are susceptible to weakness and injury induced by repetitive , dynamic , forced-lengthening contractions . Results would support the hypothesis that contraction-induced injuries could occur in hyperactive masticatory muscles of humans in response to parafunctional oral habits . Mice were anesthetized and r and omly assigned to three groups : non-treated controls , treated by repetitive passive jaw opening , or treated by repetitive isometric tetanic contractions with lengthening by jaw opening . In each treatment group , masticatory muscle injury was evaluated by contractile tension , plasma creatine kinase , and muscle glycogen . Contractile tension was determined at different stimulation frequencies and was significantly decreased 5 min , 4 h , and 72 h after repetitive contraction/lengthening . Plasma creatine kinase was significantly elevated at 4 but not at 72 h post-treatment in mice subjected to repetitive contraction/lengthening . Masticatory muscle glycogen was not significantly different in any groups at 4 or 72 h post-treatment . These results indicate that contraction injuries can be induced in masticatory muscle of mice by forced lengthening contractions which simulate eccentric contractions
Conclusion Overall , our findings do not support the presence of a secondary loss of strength following an acute muscle injury , and strongly suggest that strength , on average , recovers steadily over the first 3 days post-injury
Background An immediate loss of strength follows virtually all types of muscle injury but there is debate whether the initial strength loss is maximal or if a secondary loss of strength occurs during the first 3 days post-injury .
Objective The objective of this analysis was to conduct a systematic review and meta- analysis of the research literature to determine if a secondary loss of strength occurs after an injurious initiating event .