Analysis of the muscular activities of the tibialis anterior and gastrocnemius muscles in functional reach.

[Purpose] This study aimed to examine the changes in the muscle activities of each section of the tibialis anterior and gastrocnemius muscles in the functional reach test. [Subjects and Methods] This study selected those who can walk independently, can reach out their arm up to over 25 cm, can show over 90° shoulder joint bending, have not undergone an operation in the lower limb joint, and are not taking any medication affecting their ability to keep their balance from among 24 elderly males and 24 elderly females. The muscular activities of the tibialis anterior and gastrocnemius muscles were measured using the functional reach test and electromyogram. The functional reach test was conducted at a total of four sections: 0, 15, 20, and 25 cm. [Results] Gender and age affected the muscular activity by section in the functional reach test. It was also found that the gastrocnemius muscle was used more than the tibialis anterior muscle to keep the balance, and the aged subjects with good balance ability showed no great change in muscular activity on both stable and unstable ground. [Conclusion] It was found that the subjects used the tibialis anterior muscle more, and the lower limbs of the frequently used part, to keep their balance. As the aged subjects had good balance ability, they showed no great change in muscular activity on both stable and unstable ground.