How is walking speed related to muscle strength? A study of healthy persons and persons with late effects of polio.
OBJECTIVE
To evaluate the relationship between walking speed and muscle strength in the lower extremities in healthy persons and in persons with late effects of polio and to compare the models for these relationships.


METHODS
Retrospective analysis.


METHODS
University hospital department.


METHODS
An urban sample of 144 healthy men and women (age range, 40-79 y) and 234 (146 women, 88 men) subjects with late polio.


METHODS
Not applicable.


METHODS
Muscle strength in the lower extremities was measured and combined into an index. Walking speed for spontaneous and maximal walking was measured. A nonlinear regression model was developed.


RESULTS
Evidence was provided for the nonlinear relationship between walking speed and strength. A specific strength threshold could not be identified. The asymptote of this curve for maximal walking was 2.57 m/s in the healthy group and 2.02 m/s in the subjects with late effects of polio. A high body mass index (>25 kg/m2) lowered the asymptote.


CONCLUSIONS
It is important to prevent strength decrease that approaches the critical level where a further reduction affects walking speed more evidently. The difference in the relationship between muscle strength and walking speed for the 2 groups studied may partly depend on biomechanic imbalance between muscle groups.
Willén
Carin
C
Institute of Neurosciences-Rehabilitation Medicine, Sahlgrenska Academy, University of Göteborg, Sweden.
Sunnerhagen
Katarina Stibrant
KS
Ekman
Claes
C
Grimby
Gunnar
G
D000328:Adult; D000367:Age Factors; D000368:Aged; D015992:Body Mass Index; D005260:Female; D006801:Humans; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D011051:Poliomyelitis / Q000503:physiopathology*; D012044:Regression Analysis; D012189:Retrospective Studies; D012656:Self-Help Devices; D012737:Sex Factors; D016138:Walking / Q000502:physiology*