Electromyographic changes of leg muscles with heel lifts in women: therapeutic implications.

The effects, in women, of heel lifts on EMG activity of the medial gastrocnemius and tibialis anterior muscles were analyzed to see whether they were different from those of men. Six women who wear high-heeled shoes regularly walked on a level floor with heel heights of zero, 2.5cm, 5.0cm, and 7.5cm. Results showed that as heel height increased, there were significant and progressive decreases in gastrocnemius and tibialis anterior EMG activity during walking. This decrease in gastrocnemius EMG activity in women is the same as in men, but the decrease in tibialis anterior EMG activity in women is opposite to that seen in men. The difference in responses of the tibialis anterior muscle between men and women may be related to the habitual use of high-heeled shoes by women. Since raising the heel decreases gastrocnemius muscle activity, thereby reducing tension in the Achilles tendon in both men and women, it was felt that heel lifts may provide a useful adjunct in the management of tendoachilles bursitis, tenosynovitis of the Achilles tendon, and postoperative management of a ruptured Achilles tendon.