Abstract: Objective To establish a new model of the Achilles tendon(AT) contraction by stress-shielding. Methods 8 SD rats were randomly divided into two groups, the normal control group and the experimental group. The ATs of the experimental group were stress-shielded by fixing the upper ankle joint in equines position using a cerclage and transecting the sciatic nerve. The control group received no treatment. All rats were killed three weeks later, and all the ATs of the left hind limbs of the experimental and normal control group were tested morphologically by transmission electron microscope (TEM). Results Compared to the normal control group, the collagen fibrils of the experimental tendons did not arrange very well. The number of tendon cells increased, and some of them were pycnotic. Some mitochondrias were swollen. The proportion of the smaller diameter collagen fibril became lager, and small and large fibrils did not distribute in even. Conclusion Our research is successful compared to the past researches and repeatable.

Key words: Achilles tendon, contraction, stress-shielding