title: Assessment of Muscle Pain Induced by Elbow-Flexor Eccentric Exercise.
abstract: BACKGROUND
  Delayed-onset muscle soreness (DOMS) is a common muscle pain that many people experience and is often used as a model of acute muscle pain. Researchers have reported the effects of various interventions on DOMS, but different DOMS assessment protocols used in these studies make it difficult to compare the effects.
  
  
  OBJECTIVE
  To investigate DOMS characteristics after elbow-flexor eccentric exercise to establish a standardized DOMS assessment protocol.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Ten healthy, untrained men (21-39 years).
  
  
  METHODS
  Participants performed 10 sets of 6 maximal isokinetic eccentric contractions of the elbow flexors.
  
  
  METHODS
  Indirect muscle-damage markers were maximal voluntary isometric contraction torque, range of motion, and serum creatine kinase activity. Muscle pain was assessed before exercise, immediately postexercise, and 1 to 5 days postexercise using (1) a visual analog scale (VAS), (2) a category ratio-10 scale (CR-10) when applying static pressure and palpation at different sites (3, 9, and 15 cm above the elbow crease), and (3) pressure-pain thresholds (PPTs) at 50 sites (pain mapping).
  
  
  RESULTS
  Maximal voluntary isometric contraction and range of motion decreased and creatine kinase activity increased postexercise, indicating muscle damage. Palpation induced greater pain than static pressure, and longitudinal and transverse palpations induced greater pain than circular palpation (P < .05). The PPT was lower in the medial region before exercise, but the pain-sensitive regions shifted to the central and distal regions of the biceps brachii at 1 to 3 days postexercise (P < .05). The VAS was correlated with the CR-10 scale (r = 0.91, P < .05) but not with the PPT (r = -0.28, P = .45).
  
  
  CONCLUSIONS
  The way in which muscles are assessed affects the pain level score. This finding suggests that pain level and pain threshold cannot be used interchangeably and that the central and distal regions of the biceps brachii should be included in DOMS assessment using the VAS, CR-10 scale, and PPT after elbow-flexor eccentric exercise.
authors.affiliation: School of Exercise and Health Sciences, Edith Cowan University, Joondalup, Western Australia;
authors.forename: Wing Yin
authors.initials: WY
authors.lastname: Lau
authors.affiliation: School of Exercise and Health Sciences, Edith Cowan University, Joondalup, Western Australia;
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Blazevich
authors.affiliation: School of Psychology and Exercise Science, Murdoch University, Western Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Newton
authors.affiliation: School of Exercise and Health Sciences, Edith Cowan University, Joondalup, Western Australia;
authors.forename: Sam Shi Xuan
authors.initials: SS
authors.lastname: Wu
authors.affiliation: School of Exercise and Health Sciences, Edith Cowan University, Joondalup, Western Australia;
authors.forename: Kazunori
authors.initials: K
authors.lastname: Nosaka
mesh_terms: D000328:Adult; D001132:Arm / Q000502:physiology; D004550:Elbow / Q000502:physiology; D004551:Elbow Joint / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D063806:Myalgia / Q000209:etiology* / Q000503:physiopathology; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology; D019415:Torque; D055815:Young Adult
keywords: delayed-onset muscle soreness; muscle damage; palpation; pressure-pain threshold; visual analog scale