title: Relationships among the Y balance test, Berg Balance Scale, and lower limb strength in middle-aged and older females.
abstract: BACKGROUND
  Older females have less dynamic postural control and muscle strength than do middle-aged females. Aging-related strength losses may limit balancing performance.
  
  
  OBJECTIVE
  The purpose of this study was to investigate the ability of the Y Balance Test (YBT) and lower limb strength to discriminate between females in 2 age groups, the relationship between YBT distance and the Berg Balance Scale (BBS), and the degree to which performance on YBT distance is related to lower limb strength in middle-aged and older females.
  
  
  METHODS
  The 40 healthy, independently active females were divided into 2 groups: older and middle-aged. The participants underwent measurements of YBT distance using the YBT, maximal muscular strength of the lower limbs using a handheld dynamometer, and the BBS.
  
  
  RESULTS
  The YBT distance in 3 directions and lower limb muscle strength for both lower limbs were significantly lower in the older adults than in the middle-aged group. A moderate correlation but insignificant correlation was found between the YBT composite distance and the BBS score. In the older females, YBT distance was significantly positively correlated with strength of the knee flexor and hip abductor. In the middle-aged group, YBT distance was significantly positively correlated with strength of the knee flexor and hip extensor.
  
  
  CONCLUSIONS
  Performance on the YBT was influenced by the strength of lower limb. We suggested that YBT can be used to alternative as a measurement of dynamic balance. Proper training programs for older people could include not only strengthening exercises but also YBT performance to improve balance.
authors.affiliation: Department of Rehabilitation Science, Graduate School, INJE University, Gimhae, South Korea.
authors.forename: Dong-Kyu
authors.initials: DK
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Science, Graduate School, INJE University, Gimhae, South Korea.
authors.forename: Min-Hyeok
authors.initials: MH
authors.lastname: Kang
authors.affiliation: Department of Physical Therapy, Dong-Eui Institute of Technology, Busan, South Korea.
authors.forename: Tae-Sik
authors.initials: TS
authors.lastname: Lee
authors.affiliation: Department of Physical Therapy, College of Biomedical Science and Engineering, INJE University, Gimhae, South Korea.
authors.forename: Jae-Seop
authors.initials: JS
authors.lastname: Oh
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*