title: Myoelectrical manifestation of fatigue less prominent in patients with cancer related fatigue.
abstract: OBJECTIVE
  A lack of fatigue-related muscle contractile property changes at time of perceived physical exhaustion and greater central than peripheral fatigue detected by twitch interpolation technique have recently been reported in cancer survivors with fatigue symptoms. Based on these observations, it was hypothesized that compared to healthy people, myoelectrical manifestation of fatigue in the performing muscles would be less significant in these individuals while sustaining a prolonged motor task to self-perceived exhaustion (SPE) since their central fatigue was more prominent. The purpose of this study was to test this hypothesis by examining electromyographic (EMG) signal changes during fatiguing muscle performance.
  
  
  METHODS
  Twelve individuals who had advanced solid cancer and cancer-related fatigue (CRF), and 12 age- and gender-matched healthy controls performed a sustained elbow flexion at 30% maximal voluntary contraction till SPE. Amplitude and mean power frequency (MPF) of EMG signals of the biceps brachii, brachioradialis, and triceps brachii muscles were evaluated when the individuals experienced minimal, moderate, and severe fatigue.
  
  
  RESULTS
  CRF patients perceived physical "exhaustion" significantly sooner than the controls. The myoelectrical manifestation of muscular fatigue assessed by EMG amplitude and MPF was less significant in CRF than controls. The lower MPF even at minimal fatigue stage in CRF may indicate pathophysiologic condition of the muscle.
  
  
  CONCLUSIONS
  CRF patients experience less myoelectrical manifestation of muscle fatigue than healthy individuals near the time of SPE. The data suggest that central nervous system fatigue plays a more important role in limiting endurance-type of motor performance in patients with CRF.
authors.affiliation: Department of Biomedical Engineering, the Lerner Research Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America ; Department of Kinesiology, Faculty of Physiotherapy, University School of Physical Education in Wroclaw, Wroclaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kisiel-Sajewicz
authors.affiliation: Department of Biomedical Engineering, the Lerner Research Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America ; Department of Physical Medicine and Rehabilitation, the Neurological Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Vlodek
authors.initials: V
authors.lastname: Siemionow
authors.affiliation: The Harry R. Horvitz Center for Palliative Medicine, the Taussig Cancer Center, the Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Dilara
authors.initials: D
authors.lastname: Seyidova-Khoshknabi
authors.affiliation: The Harry R. Horvitz Center for Palliative Medicine, the Taussig Cancer Center, the Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Mellar P
authors.initials: MP
authors.lastname: Davis
authors.affiliation: Department of Biomedical Engineering, the Lerner Research Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Alexandria
authors.initials: A
authors.lastname: Wyant
authors.affiliation: Department of Biomedical Engineering, the Lerner Research Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America ; Department of Physical Medicine and Rehabilitation, the Neurological Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Vinoth K
authors.initials: VK
authors.lastname: Ranganathan
authors.affiliation: The Harry R. Horvitz Center for Palliative Medicine, the Taussig Cancer Center, the Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Declan
authors.initials: D
authors.lastname: Walsh
authors.affiliation: Institute of Affective and Social Neuroscience, Shenzhen University, Shenzhen; Department of Psychology, Tsinghuan University, Beijing, China.
authors.forename: Jin H
authors.initials: JH
authors.lastname: Yan
authors.affiliation: Department of Physical Medicine and Rehabilitation, the Neurological Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Juliet
authors.initials: J
authors.lastname: Hou
authors.affiliation: Department of Biomedical Engineering, the Lerner Research Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America ; Department of Physical Medicine and Rehabilitation, the Neurological Institute, the Cleveland Clinic, Cleveland, Ohio, United States of America ; Kessler Foundation Research Center, West Orange, New Jersey, United States of America.
authors.forename: Guang H
authors.initials: GH
authors.lastname: Yue
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D004558:Electric Stimulation; D004576:Electromyography; D005221:Fatigue / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D018908:Muscle Weakness / Q000209:etiology / Q000503:physiopathology; D009369:Neoplasms / Q000150:complications* / Q000503:physiopathology*; D010465:Perception; D010807:Physical Endurance / Q000502:physiology