Wu, F and Callisaya, M and Laslett, LL and Wills, K and Zhou, Y and Jones, G and Winzenberg, T, Lower limb muscle strength is associated with poor balance in middle-aged women: linear and nonlinear analyses, Osteoporosis International, 27, (7) pp. 2241-2248. ISSN 0937-941X (2016) [Refereed Article]
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Copyright International Osteoporosis Foundation and National Osteoporosis Foundation 2016 This is a post-peer-review, pre-copyedit version of an article published in Osteoporosis International. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00198-016-3545-3.
This was the first study investigating both linear associations between lower limb muscle strength and balance in middle-aged women and the potential for thresholds for the associations. There was strong evidence that even in middle-aged women, poorer LMS was associated with reduced balance. However, no evidence was found for thresholds.
INTRODUCTION: Decline in balance begins in middle age, yet, the role of muscle strength in balance is rarely examined in this age group. We aimed to determine the association between lower limb muscle strength (LMS) and balance in middle-aged women and investigate whether cut-points of LMS exist that might identify women at risk of poorer balance.
METHODS: Cross-sectional analysis of 345 women aged 36-57 years was done. Associations between LMS and balance tests (timed up and go (TUG), step test (ST), functional reach test (FRT), and lateral reach test (LRT)) were assessed using linear regression. Nonlinear associations were explored using locally weighted regression smoothing (LOWESS) and potential cut-points identified using nonlinear least-squares estimation. Segmented regression was used to estimate associations above and below the identified cut-points.
RESULTS: Weaker LMS was associated with poorer performance on the TUG (β -0.008 (95 % CI: -0.010, -0.005) second/kg), ST (β 0.031 (0.011, 0.051) step/kg), FRT (β 0.071 (0.047, 0.096) cm/kg), and LRT (β 0.028 (0.011, 0.044) cm/kg), independent of confounders. Potential nonlinear associations were evident from LOWESS results; significant cut-points of LMS were identified for all balance tests (29-50 kg). However, excepting ST, cut-points did not persist after excluding potentially influential data points.
CONCLUSIONS: In middle-aged women, poorer LMS is associated with reduced balance. Therefore, improving muscle strength in middle-age may be a useful strategy to improve balance and reduce falls risk in later life. Middle-aged women with low muscle strength may be an effective target group for future randomized controlled trials.
|Item Type:||Refereed Article|
|Keywords:||Balance, Middle-aged women, Muscle strength|
|Research Division:||Medical and Health Sciences|
|Research Group:||Clinical Sciences|
|Research Field:||Rheumatology and Arthritis|
|Objective Group:||Clinical Health (Organs, Diseases and Abnormal Conditions)|
|Objective Field:||Skeletal System and Disorders (incl. Arthritis)|
|Author:||Wu, F (Mr Feitong Wu)|
|Author:||Callisaya, M (Dr Michele Callisaya)|
|Author:||Laslett, LL (Dr Laura Laslett)|
|Author:||Wills, K (Dr Karen Wills)|
|Author:||Zhou, Y (Mr Yuan Zhou)|
|Author:||Jones, G (Professor Graeme Jones)|
|Author:||Winzenberg, T (Professor Tania Winzenberg)|
|Web of Science® Times Cited:||5|
|Deposited By:||Menzies Institute for Medical Research|
|Downloads:||1 View Download Statistics|
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