THE EFFECT OF WEARING INSOLES WITH A TOE-GRIP BAR ON OCCUPATIONAL LEG SWELLING AND LOWER LIMB MUSCLE ACTIVITY

H. Nakano¹, S. Murata¹, Y. Kai¹, T. Abiko¹, D. Matsuo², M. Kawaguchi²

Background: It has been reported that occupational leg symptoms, such as leg swelling, leg pain, and the feeling of heaviness and tension in the legs, occur frequently in healthy individuals who work for hours at sitting and standing positions. Sitting or standing for hours decreases the blood flow in the legs and results in increased pressure on the veins; therefore, prolonged sitting and standing are both risk factors for the development of chronic venous disease. Occupational leg symptoms, especially leg swelling is associated with feelings of tiredness and heaviness of the legs, and leg pain. Therefore, reducing leg swelling is important in preventing the development of chronic venous disease. Insoles with a toe-grip bar, which improve the toe-grip strength and reduce leg swelling while the individual is walking, have been developed recently. It has been reported that the insoles with a toe-grip bar improved the toe-grip strength in healthy individuals and that it attenuates leg swelling in middle-aged and elderly women. This may be due to the promotion of the skeletal muscle pump function by using the insoles. A previous study reported on the muscle activity of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius muscles during the toe-grip movement in a standing position. Therefore, we hypothesized that insoles with a toe-grip bar may increase lower limb muscle activity, resulting in the attenuation of leg swelling.

Purpose: This study aimed to investigate the effects of insoles with a toe-grip bar on occupational leg swelling and lower limb muscle activity.

Methods: This randomized cross-over study enrolled 12 healthy men who work in a sitting or standing position. They were randomly divided into groups A (wore shoes with insoles with a toe-grip bar for 8 hours) and B (wore shoes with regular insoles for 8 hours) each. After 1 week, groups A and B wore shoes with regular insoles and shoes with insoles with a toe-grip bar, respectively, for 8 hours each. Lower leg volume was measured before and after each intervention, and the number of steps during each intervention was measured. Moreover, lower limb muscle activity was measured at the start of each intervention.

Results: Occupational leg swelling was significantly smaller in men wearing insoles with a toe-grip bar than in those wearing regular insoles. There was no significant difference between insoles with a toe-grip bar and regular insoles in terms of baseline lower leg volume and the number of steps. The integrated electromyogram value of the tibialis anterior muscle and medial and lateral gastrocnemius muscles during the stance phase of walking, and the tibialis anterior muscle during the swing phase of walking was significantly greater in men wearing insoles with a toe-grip bar than in those wearing regular insoles.

Conclusion(s): The findings of this study suggest that insoles with a toe-grip bar could contribute to the attenuation of occupational leg swelling and the increase in lower limb muscle activity.

Implications: Insoles with a toe-grip bar can be widely applied as a simple tool of physiotherapy practice to reduce leg swelling just by walking.

Funding, acknowledgements: None.

Keywords: Insole, Occupational leg swelling, Lower limb muscle activity

Topic: Occupational health & ergonomics

Did this work require ethics approval? Yes

Institution: Kyoto Tachibana University

Committee: Kyoto Tachibana University

Ethics number: 19-20