title: The importance of trunk muscle strength for balance, functional performance, and fall prevention in seniors: a systematic review.
abstract: BACKGROUND
  The aging process results in a number of functional (e.g., deficits in balance and strength/power performance), neural (e.g., loss of sensory/motor neurons), muscular (e.g., atrophy of type-II muscle fibers in particular), and bone-related (e.g., osteoporosis) deteriorations. Traditionally, balance and/or lower extremity resistance training were used to mitigate these age-related deficits. However, the effects of resistance training are limited and poorly translate into improvements in balance, functional tasks, activities of daily living, and fall rates. Thus, it is necessary to develop and design new intervention programs that are specifically tailored to counteract age-related weaknesses. Recent studies indicate that measures of trunk muscle strength (TMS) are associated with variables of static/dynamic balance, functional performance, and falls (i.e., occurrence, fear, rate, and/or risk of falls). Further, there is preliminary evidence in the literature that core strength training (CST) and Pilates exercise training (PET) have a positive influence on measures of strength, balance, functional performance, and falls in older adults.
  
  
  OBJECTIVE
  The objectives of this systematic literature review are: (a) to report potential associations between TMS/trunk muscle composition and balance, functional performance, and falls in old adults, and (b) to describe and discuss the effects of CST/PET on measures of TMS, balance, functional performance, and falls in seniors.
  
  
  METHODS
  A systematic approach was employed to capture all articles related to TMS/trunk muscle composition, balance, functional performance, and falls in seniors that were identified using the electronic databases PubMed and Web of Science (1972 to February 2013).
  
  
  METHODS
  A systematic approach was used to evaluate the 582 articles identified for initial review. Cross-sectional (i.e., relationship) or longitudinal (i.e., intervention) studies were included if they investigated TMS and an outcome-related measure of balance, functional performance, and/or falls. In total, 20 studies met the inclusionary criteria for review.
  
  
  METHODS
  Longitudinal studies were evaluated using the Physiotherapy Evidence Database (PEDro) scale. Effect sizes (ES) were calculated whenever possible. For ease of discussion, the 20 articles were separated into three groups [i.e., cross-sectional (n = 6), CST (n = 9), PET (n = 5)].
  
  
  RESULTS
  The cross-sectional studies reported small-to-medium correlations between TMS/trunk muscle composition and balance, functional performance, and falls in older adults. Further, CST and/or PET proved to be feasible exercise programs for seniors with high-adherence rates. Age-related deficits in measures of TMS, balance, functional performance, and falls can be mitigated by CST (mean strength gain = 30 %, mean effect size = 0.99; mean balance/functional performance gain = 23 %, mean ES = 0.88) and by PET (mean strength gain = 12 %, mean ES = 0.52; mean balance/functional performance gain = 18 %, mean ES = 0.71).
  
  
  CONCLUSIONS
  Given that the mean PEDro quality score did not reach the predetermined cut-off of ≥6 for the intervention studies, there is a need for more high-quality studies to explicitly identify the relevance of CST and PET to the elderly population.
  
  
  CONCLUSIONS
  Core strength training and/or PET can be used as an adjunct or even alternative to traditional balance and/or resistance training programs for old adults. Further, CST and PET are easy to administer in a group setting or in individual fall preventive or rehabilitative intervention programs because little equipment and space is needed to perform such exercises.
authors.affiliation: Department of Training and Movement Sciences, Cluster of Excellency in Cognition Sciences, University of Potsdam, Am Neuen Palais 10, Haus 12, 14469 Potsdam, Germany. urs.granacher@uni-potsdam.de
authors.forename: Urs
authors.initials: U
authors.lastname: Granacher
authors.forename: Albert
authors.initials: A
authors.lastname: Gollhofer
authors.forename: Tibor
authors.initials: T
authors.lastname: Hortobágyi
authors.forename: Reto W
authors.initials: RW
authors.lastname: Kressig
authors.forename: Thomas
authors.initials: T
authors.lastname: Muehlbauer
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D026241:Exercise Movement Techniques / Q000379:methods*; D006801:Humans; D053580:Muscle Strength / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D055070:Resistance Training / Q000379:methods*; D060726:Torso / Q000502:physiology*