Differences between Proximal and Distal Muscle Activity of the Lower Limbs of Community-dwelling Women during the 6-minute Walk Test

[Purpose] This study examined the change in the muscle activities of the lower limbs during the 6-minute walk test to identify the relationship between the change in muscle activity and physical performance of community-dwelling elderly women. [Methods] Twenty-three elderly women (mean age: 77.9 years) were recruited from the community to participate. Their muscle activities were recorded using surface electromyography of the gastrocnemius, tibialis anterior, vastus medialis, hamstrings, and gluteus medius, and muscle strength, mobility, balance and 6-minute walking distance were also measured. [Results] The decrease of electromyography activity during the 6-minute walk test was significantly greater in the gastrocnemius and tibialis anterior than in the other muscles. The decrease of electromyography activity in the gastrocnemius was correlated with the timed up-and-go time (r= –0.435) and that of the tibialis anterior was correlated with the timed up-and-go time (r= –0.530) and walking distance (r= 0.482). [Conclusions] The electromyogram activities of the gastrocnemius and the tibialis anterior showed deterioration during the 6-minute walk test, and they were correlated with gait performance. These results suggest that muscle activity of the distal muscles plays an important role in the walking ability of elderly women.