Prevention in dangerous industries: does safety certification prevent tree-faller injuries?

OBJECTIVES: The aim of this study was to evaluate if safety certification reduces the risk of work injury among experienced manual tree-fallers. METHODS: This study used a retrospective cohort study design. Experienced manual tree-fallers employed in the Canadian province of British Columbia (N=3251) between 2003-2008 were enumerated from a mandatory faller registry. Registry records with demographic and certification data were linked to workers' compensation claims for injury outcomes. Data were analyzed using discrete time survival analysis over a two-year period, centered on certification date with pre- and post-certification demarcated into four three-month periods. Models were adjusted for demographic, occupation/industry, previous injury, and seasonal/temporal effects. RESULTS: The relative risk (RR) of work injury during the post certification periods were elevated in comparison to the pre-certification reference period, but the 95% confidence intervals included "1" for all estimates by the end of follow-up, suggesting no statistically significant increased risk of injury. Results were consistent across different outcome measures of acute injury (ie, fracture or amputations) (N=186), musculoskeletal injury (ie, back strain) (N=137), and serious injury claims (ie, long duration, high cost and/or fatal) (N=155). CONCLUSION: Certification did not reduce the risk of work injury among experienced tree-fallers in the province of British Columbia. Non-statistically significant increases in the observed risk of work injury in the months immediately following certification may be attributable to an intervention effect or a methodological limitation related to a lack of individual-level, time-at-risk exposure data.

Metabolic requirements of interactive video game cycling.

BACKGROUND: Interactive video game exercise leads to improved exercise adherence and health-related physical fitness in comparison to traditional stationary cycling. It has been postulated that interactive video game exercise has greater metabolic requirements than traditional cycling; however, this has not been tested to date. PURPOSE: To examine the metabolic requirements of interactive video game exercise in comparison to traditional stationary cycling at matched incremental workloads. METHODS: Fourteen participants (seven males and seven females) were examined during three separate sessions: 1) incremental cycle ergometer exercise for the assessment of maximal aerobic power and peak workload; 2) traditional cycling on a cycle ergometer using 5-min constant workloads of 25%, 50%, and 75% of maximal power output; and 3) cycling using identical constant, relative workloads while playing interactive video games. Measurements of oxygen consumption, heart rate, and rating of perceived exertion were assessed throughout. RESULTS: During interactive video game exercise, steady-state heart rate (26% +/- 18% and 14% +/- 13%), energy expenditure (61% +/- 41% and 25% +/- 21%), and oxygen consumption (34% +/- 17% and 18% +/- 12%) were significantly higher at the constant submaximal workloads of 25% and 50%, respectively. There was no significant difference in rating of perceived exertion between conditions at any workload. CONCLUSIONS: Interactive video game cycling results in greater metabolic requirements (despite similar perceptions of exertion) at submaximal constant workloads than traditional cycling. This form of training may be a novel and an attractive intervention in the battle against physical inactivity and associated health complications.