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Serum [25(OH)D] status, ankle strength and activity show seasonal variation in older adults: relevance for winter falls in higher latitudes


Bird, M-L and Hill, KD and Robertson, IK and Ball, MJ and Pittaway, J and Williams, AD, Serum [25(OH)D] status, ankle strength and activity show seasonal variation in older adults: relevance for winter falls in higher latitudes, Age and Ageing, 42, (2) pp. 181-185. ISSN 0002-0729 (2013) [Refereed Article]

Copyright Statement

Copyright 2013 Oxford University Press

DOI: doi:10.1093/ageing/afs067


Background: seasonal variation exists in serum [25(OH)D] and physical activity, especially at higher latitudes, and these factors impact lower limb strength. This study investigates seasonal variation in leg strength in a longitudinal repeated measures design concurrently with serum vitamin D and physical activity.

Methods: eighty-eight community-dwelling independently mobile older adults (69.2 6.5 years) were evaluated five times over a year, at the end of five consecutive seasons at latitude 41.1S, recruited in two cohorts. Leg strength, serum [25(OH)D] and physical activity levels were measured. Time spent outside was recorded. Monthly falls diaries recorded falls. Data were analysed to determine annual means and percentage changes.

Results: significant variation in [25(OH)D] (15%), physical activity (13%), ankle dorsiflexion strength (8%) and hours spent outside (20%) (all P < 0.001) was demonstrated over the year, with maximums in January and February (mid-summer). Low mean ankle strength was associated with increased incidence of falling (P = 0.047). Quadriceps strength did not change (2%; P = 0.53).

Conclusion: ankle dorsiflexor strength varied seasonally. Increased ankle strength in summer may be influenced by increased levels of outdoors activity over the summer months. Reduced winter-time dorsiflexor strength may predispose older people to increased risk of tripping-related falls, and warrants investigation in a multi-faceted falls prevention programme.

Item Details

Item Type:Refereed Article
Keywords:elderly, exercise, preventative measures, physical activity, accidental falls
Research Division:Biomedical and Clinical Sciences
Research Group:Medical biochemistry and metabolomics
Research Field:Metabolic medicine
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Bird, M-L (Dr Marie-Louise Bird)
UTAS Author:Robertson, IK (Dr Iain Robertson)
UTAS Author:Ball, MJ (Professor Madeleine Ball)
UTAS Author:Pittaway, J (Ms Jane Pittaway)
UTAS Author:Williams, AD (Associate Professor Andrew Williams)
ID Code:79549
Year Published:2013
Web of Science® Times Cited:18
Deposited By:Health Sciences A
Deposited On:2012-09-19
Last Modified:2017-11-02

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