Background:Apreviousstudyhasreporteda50%reductionindisuseatrophyofthequadricepsduringthefirst14daysafteranteriorcruciateligament(ACL)reconstruction.Afollow-uptrialisneededtoconfirmthesepromisingresults.ThepresentstudyaimstoinvestigatetheeffectofanocclusionstimulusonquadricepsatrophyafterACLreconstruction.Methods:Atotalof24subjectsparticipatedinthestudy.Theywererandomizedintotwogroups.Startingthe2nddayaftersurgery,theocclusiongroupreceivedanocclusionstimulusfor5min,followedbyremovaloftheocclusivepressurefor3min.Thiswasrepeatedfivetimesinonetrainingsession,twicedaily.Duringtheperiodofocclusivestimulus,thesubjectsperformed20lowloadexercisesforthequadriceps.Thecontrolgroupfollowedthesameexerciseprotocol,butwithouttheocclusionstimulus.Changesinquadricepsanatomicalcrosssectionarea(ACSA)weremeasuredusingaxialmagneticresonance(MR)imagesat40%and50%ofthelengthofthefemur.Results:BothgroupshadasignificantreductionofquadricepsACSAfrom2daysbeforesurgeryto16daysaftersurgery.Duringtheinterventionperiod,theocclusiongrouplost13.8%±1.1%(mean±SEM)andthecontrolgrouplost13.1%±1.0%oftheirquadricepsACSA,respectively.Therewasnosignificantdifferencebetweentheocclusionandcontrolgroupswithregardstoatrophyofthequadricepsmuscles.Conclusion:Inconflictwithotherstudiesusingasimilarprotocol,applicationofbloodflowrestrictionthefirst14daysafterACLreconstructiondidnotreducequadricepsACSAmuscleatrophymeasuredbyMRinapopulationofathletes.
