title: Effect of diathermy on muscle temperature, electromyography, and mechanomyography.
abstract: This study examined the effects of pulsed shortwave diathermy on intramuscular temperature, surface electromyography (EMG), and mechanomyography (MMG) of the vastus lateralis. Thirty-five men were assigned to diathermy (n = 13), sham-diathermy (n = 12), or control (n = 10) groups. Each subject performed isometric maximal voluntary contractions (MVCs) and incremental ramp contractions (10%-90% MVC) before and after treatment. Torque, intramuscular temperature, EMG, and MMG were recorded. Temperature for the diathermy group increased (P <or= 0.05). MMG amplitude and instantaneous mean frequency (IMF) increased (P <or= 0.05) during the MVCs with the greatest increases observed for the diathermy group. During ramp contractions, MMG amplitude and IMF increased at all percentages of MVC (10%-90%) for the diathermy group only (P <or= 0.05). There were no changes in MVC torque, EMG amplitude, or IMF. Diathermy treatments may decrease musculotendinous stiffness, but not absolute strength or motor control strategies that influence force production.
authors.affiliation: Athletic Training Education, Texas A&M University - Commerce, Commerce, Texas, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Mitchell
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Trowbridge
authors.forename: A Louise
authors.initials: AL
authors.lastname: Fincher
authors.forename: Joel T
authors.initials: JT
authors.lastname: Cramer
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D001831:Body Temperature / Q000528:radiation effects*; D003972:Diathermy / Q000379:methods*; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology / Q000528:radiation effects; D018482:Muscle, Skeletal / Q000502:physiology* / Q000528:radiation effects*; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013314:Stress, Mechanical