On-field testing environment and balance error scoring system performance during preseason screening of healthy collegiate baseball players

J Athl Train. 2007 Oct-Dec;42(4):446-51.


Context: To determine if testing environment affects Balance Error Scoring System (BESS) scores in healthy collegiate baseball players.

Design: Experimental, randomized, repeated-measures design with a sample of convenience.

Setting: Uncontrolled sideline and controlled locker room baseball environments.

Patients or other participants: A total of 21 healthy collegiate baseball players (age = 20.1 +/- 1.4 years, height = 185.1 +/- 6.8 cm, mass = 86.3 +/- 9.5 kg) with no history of head injury within the last 12 months, no lower extremity injuries reported within the past 2 months that caused them to miss 1 or more days of practice or game time, and no history of otitis media, Parkinson disease, or Meniere disease.

Main outcome measure(s): Participants performed the BESS test in 2 environments, controlled locker room and uncontrolled sideline, in 2 testing sessions 1 week apart during the baseball preseason. The BESS scores were evaluated for each of the 6 conditions and total score across the testing sessions. Separate, paired-samples t tests with Bonferroni adjustment (P < .008) were used to examine differences between testing environments for each BESS subcategory and total score. Cohen d tests were calculated to evaluate effect sizes and relative change.

Results: Significant group mean differences were found between testing environments for single-leg foam stance (P = .001), with higher scores reported for the uncontrolled sideline environment (7.33 +/- 2.11 errors) compared with the controlled clinical environment (5.19 +/- 2.16 errors). Medium to large effect sizes (0.53 to 1.03) were also found for single-leg foam, tandem foam, and total BESS scores, with relative increases (worse scores) of 30% to 44% in the sideline environment compared with the clinical environment.

Conclusions: The BESS performance was impaired when participants were tested in a sideline environment compared with a clinical environment. Baseline testing for postural control using the BESS should be conducted in the setting or environment in which testing after injury will most likely be conducted.

Keywords: attention; concussion; environment; postural control.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Baseball / injuries
  • Baseball / physiology*
  • Biomechanical Phenomena
  • Brain Concussion / physiopathology
  • Humans
  • Joint Instability / physiopathology
  • Male
  • Postural Balance / physiology*
  • Posture / physiology*
  • Proprioception / physiology