title: A system for predicting musculoskeletal disorders among dental students.
abstract: OBJECTIVE
  This study aimed to develop a system for predicting work-related musculoskeletal disorders (WMSD) among dental students.
  
  
  METHODS
  The system comprised 2 accelerometer sensors to register neck and upper back postures and movements, and software developed to collect and process the data. Hidden Markov models (HMMs) were used to predict the likelihood of WMSD in dental students by comparing their neck and upper back movement patterns with WMSD and non-WMSD HMMs learned from previous data. To evaluate the performance of the system, 16 participants were randomly assigned into a 2 × 2 crossover trial scheduled for each sequence of working: receiving feedback or no-feedback from the system. The primary outcome measure was the extension of the neck and upper back, before (pre-test) and after (posttest) receiving feedback or no-feedback from the system. The secondary outcome measure was the log likelihood of classifying the movements as WMSD.
  
  
  CONCLUSIONS
  The results showed that in the group that received feedback, the extension of the neck in the y axis and of the upper back in the y axis decreased significantly (t test, p < .05) on the post-test.
  
  
  CONCLUSIONS
  The system for predicting and preventing WMSD aids the correction of the extension of the neck and upper back in the y axis.
authors.affiliation: Faculty of Dentistry, Srinakarinwirot University, Bangkok, Thailand.
authors.forename: Bhornsawan
authors.initials: B
authors.lastname: Thanathornwong
authors.affiliation: Faculty of Dentistry, Thammasat University, Pathumthani, Thailand. siriwan.suebnukarn@gmail.com.
authors.forename: Siriwan
authors.initials: S
authors.lastname: Suebnukarn
authors.affiliation: School of Engineering and Technology, Asian Institute of Technology, Pathumthani, Thailand.
authors.forename: Kan
authors.initials: K
authors.lastname: Ouivirach
mesh_terms: D061725:Accelerometry; D000328:Adult; D001415:Back / Q000502:physiology; D025461:Feedback, Physiological / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008390:Markov Chains; D009068:Movement / Q000502:physiology; D009140:Musculoskeletal Diseases / Q000517:prevention & control*; D009333:Neck / Q000502:physiology; D009784:Occupational Diseases / Q000517:prevention & control*; D016272:Occupational Health; D011187:Posture; D012307:Risk Factors; D013335:Students, Dental