title: Relationship between standing posture and stability.
abstract: OBJECTIVE
  This study determined whether persons with stability impairments have postural aberrations. We investigated whole-body posture and its relationship to center-of-gravity (COG) stability.
  
  
  METHODS
  Data from 27 subjects with vestibular hypofunction and 26 subjects without vestibular impairment were analyzed.
  
  
  METHODS
  An optoelectronic full-body system measured kinematics. Force plates measured ground reaction forces while subjects stood with their feet 30 cm apart and eyes open and with their feet together and eyes closed.
  
  
  RESULTS
  The subjects with vestibular hypofunction demonstrated less stability than the subjects without impairment, but there were no postural differences. Subjects with vestibular hypofunction had more weight on the left lower extremity during standing with feet apart. In all subjects in both groups, during standing with feet apart, the COG was anterior to the ankle, knee, back, and shoulder and posterior to the hip and neck. Subjects had an anterior pelvic tilt, extended trunk and head, right laterally flexed trunk and pelvis, and flexed knees. With their feet together, subjects increased their anterior pelvic tilt; trunk, head, and knee flexion; and anterior COG position.
  
  
  CONCLUSIONS
  Posture and stability had a low correlation. Subjects with bilateral vestibular hypofunction did not demonstrate a forward head or backward trunk lean, as has been reported anecdotally. Changing from standing with feet apart to feet together increased whole-body movement patterns to control standing stability.
authors.affiliation: MGH Institute of Health Professions, Boston 02114-4719, USA. krebs.david@mgh.harvard.edu
authors.forename: C G
authors.initials: CG
authors.lastname: Danis
authors.forename: D E
authors.initials: DE
authors.lastname: Krebs
authors.forename: K M
authors.initials: KM
authors.lastname: Gill-Body
authors.forename: S
authors.initials: S
authors.lastname: Sahrmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D005260:Female; D006112:Gravitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology*; D011446:Prospective Studies; D015837:Vestibular Diseases / Q000503:physiopathology*; D016474:Weight-Bearing