Abstract: Objective To explore the relevance between gait speed and muscle strength of lower extremities, or several kinds of physical functional tests. Methods 341 community-dwelling individuals (160 males, 181 females) aged 65-94 years were selected. They were divided into suspected sarcopenia group (n=137) and normal group (n=204) by their gait speed less or more than 0.8 m/s. It was compared between both groups with the basic physical characteristics, strength of iliopsoas, quadriceps, hamstrings and tibialis anterior, and the scores of One Leg Standing Test, Berg Balance Scale, Functional Gait Assessment, Functional Stretch Test and Timed Up and Go Test. Results The subjects were older in the suspected sarcopenia group than in the normal group. The difference of body weight, height were not statistically significant between groups. The strength of the muscles in bilateral lower limbs was not significantly different between both groups (P>0.05), while the gait speed positively correlated with the strength of iliopsoas, quadriceps and hamstrings (r=0.121-0.227, P<0.05), but not with the tibialis anterior (P>0.05). Gait speed positively correlated with the scores of One Leg Standing Test, Berg Balance Scale, Functional Gait Assessment, Functional Stretch Test (P<0.05), and negatively correlated with the score of Timed Up and Go Test (r=-0.502, P<0.001). The scores of all the tests were significantly different between 2 groups (P<0.05), except that of Functional Stretch Test (P=0.28). Conclusion Sarcopenia diagnosis is not only depended on the strength of muscle of lower extremity, but also their functions.

Key words: sarcopenia, muscle strength, lower extremities, gait speed, One Leg Standing Test, Berg Balance Scale, Functional Gait Assessment, Timed Up and Go Test, Functional Stretch Test