title: Lumbar- and Cervicothoracic-Spine Loading During a Fast-Bowling Spell.
abstract: BACKGROUND
  Epidemiological studies highlight a prevalence of lumbar vertebrae injuries in cricket fast bowlers, with governing bodies implementing rules to reduce exposure. Analysis typically requires complex and laboratory-based biomechanical analyses, lacking ecological validity. Developments in GPS microtechnologies facilitate on-field measures of mechanical intensity, facilitating screening toward prevention and rehabilitation.
  
  
  OBJECTIVE
  To examine the efficacy of using GPS-mounted triaxial accelerometers to quantify accumulated body load and to investigate the effect of GPS-unit placement in relation to epidemiological observations.
  
  
  METHODS
  Repeated measures, field-based.
  
  
  METHODS
  Regulation cricket pitch.
  
  
  METHODS
  10 male injury-free participants recruited from a cricket academy (18.1 ± 0.6 y).
  
  
  METHODS
  Each participant was fitted with 2 GPS units placed at the cervicothoracic and lumbar spines to measure triaxial acceleration (100 Hz). Participants were instructed to deliver a 7-over spell of fast bowling, as dictated by governing-body guidelines.
  
  
  METHODS
  Triaxial total accumulated body and the relative uniaxial contributions were calculated for each over.
  
  
  RESULTS
  There was no significant main effect for overs bowled, in either total load or the triaxial contributions to total load. This finding suggests no cumulative fatigue effect across the 10-over spell. However, there was a significant main effect for GPS-unit location, with the lumbar unit exposed to significantly greater load than the cervicothoracic unit in each of the triaxial planes.
  
  
  CONCLUSIONS
  There was no evidence to suggest that accumulated load significantly increased as a result of spell duration. In this respect the governing-body guidelines for this age group can be considered safe, or potentially even conservative. However, the observation of higher body load at the lumbar spine than at the cervicothoracic spine supports epidemiological observations of injury incidence. GPS microtechnologies might therefore be considered in screening and monitoring of players toward injury prevention and/or during rehabilitation.
authors.forename: Matt
authors.initials: M
authors.lastname: Greig
authors.forename: Philip
authors.initials: P
authors.lastname: Nagy
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000517:prevention & control; D001484:Baseball; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae / Q000502:physiology*; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology*; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D013177:Sports / Q000502:physiology*; D013314:Stress, Mechanical
keywords: acceleration; back injury; cricket bowling