title: Factors predicting dynamic balance and quality of life in home-dwelling elderly women.
abstract: BACKGROUND
  Proper balance seems to be a critical factor in terms of fall prevention among the elderly.
  
  
  OBJECTIVE
  The purpose of this cross-sectional study was to examine factors that are associated with dynamic balance and health-related quality of life in home-dwelling elderly women.
  
  
  METHODS
  One hundred and fifty-three healthy postmenopausal women (mean age: 72 years, height: 159 cm, weight: 72 kg) were examined. General health and physical activity were assessed by a questionnaire. Quality of life was measured using a health-related quality of life questionnaire (Rand 36-Item Health Survey 1.0). Dynamic balance (agility) was tested by a figure-of-eight running test. Static balance (postural sway) was tested on an unstable platform. Maximal isometric strength of the leg extensors was measured with a leg press dynamometer. Dynamic muscle strength of lower limbs was tested by measuring ground reaction forces with a force platform during common daily activities (sit-to-stand and step-on-a-stair tests).
  
  
  RESULTS
  Concerning physical activity, 33% of the subjects reported brisk exercise (walking, Nordic walking, cross-country skiing, swimming and aquatic exercises) at least twice a week, and 22% some kind of brisk activity once a week in addition to lighter physical exercise. The remaining 45% did not exercise regularly and were classified as sedentary. The correlations of step-on-a-stair and sit-to-stand ground reaction forces, and leg extensor strength to dynamic balance were from -0.32 to -0.43 (the better the strength, the better the balance). In the regression analysis with backward elimination, step-on-a-stair and sit-to-stand ground reaction forces, and leg extensor strength, age, brisk physical activity, number of diseases and dynamic postural stability explained 42% of the variance in the dynamic balance. Similarly, dynamic balance (figure-of-eight running time), number of diseases and walking more than 3 km per day explained 14% of the variance in the quality of life score. Of these, figure-of-eight running time was the strongest predictor of the quality of life score, explaining 9% of its variance.
  
  
  CONCLUSIONS
  This study emphasizes the concept that in home-dwelling elderly women good muscle strength in lower limbs is crucial for proper body balance and that dynamic balance is an independent predictor of a standardized quality of life estimate. The results provide important and useful information when planning meaningful contents for studies related to fall prevention and quality of life and interventions in elderly women.
authors.affiliation: UKK Institute for Health Promotion Research, Tampere, Finland. saija.karinkanta@uta.fi
authors.forename: S
authors.initials: S
authors.lastname: Karinkanta
authors.forename: A
authors.initials: A
authors.lastname: Heinonen
authors.forename: H
authors.initials: H
authors.lastname: Sievanen
authors.forename: K
authors.initials: K
authors.lastname: Uusi-Rasi
authors.forename: P
authors.initials: P
authors.lastname: Kannus
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control; D000368:Aged; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D004856:Postural Balance; D011788:Quality of Life; D012307:Risk Factors; D011795:Surveys and Questionnaires