Leg extension power asymmetry and mobility limitation in healthy older women.
OBJECTIVE
To investigate the association of asymmetry in leg extension power (LEP) with walking and standing balance.


METHODS
Cross-sectional analysis.


METHODS
Research laboratory.


METHODS
Healthy female twins (N=419), ages 63 to 75 years.


METHODS
Not applicable.


METHODS
The LEP difference between the stronger and the weaker leg, measured with the Nottingham power rig, was calculated. Ten-meter maximal walking velocity was assessed in a laboratory corridor on a wide (170 cm) and narrow (35 cm) track, and the ability to maintain tandem stance for 20 seconds was recorded.


RESULTS
The mean LEP difference +/- standard deviation between the legs was 15%+/-9% (P<.001). Those with large LEP difference had lower walking velocity and poorer standing balance than those with small LEP difference, in particular when the LEP of the stronger leg was below the median.


CONCLUSIONS
Even in healthy older women, substantial LEP asymmetry between the lower limbs was present, encumbering walking and standing balance. Lower-limb muscle power asymmetry warrants further study in order to develop well-targeted strategies for preventing mobility limitation in older people.
Portegijs
Erja
E
Department of Health Sciences, University of Jyväskylä, Jyväskylä.
Sipilä
Sarianna
S
Alen
Markku
M
Kaprio
Jaakko
J
Koskenvuo
Markku
M
Tiainen
Kristina
K
Rantanen
Taina
T
D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D009142:Musculoskeletal Physiological Phenomena; D010809:Physical Fitness; D004856:Postural Balance / Q000502:physiology*; D011336:Probability; D016059:Range of Motion, Articular / Q000502:physiology*; D012016:Reference Values; D012680:Sensitivity and Specificity; D014427:Twins; D016138:Walking