I think perhaps there is a basis to say that through not eating the Gid HaNasheh, we are actually strengthing and healing Yaakov Avinu's leg. This particular mitzwah is associated with this part of the body, and through performing this mitzwah we are returning our collective soul to this part of the collective body from whence it was driven out.
This is mentioned by-the-way in the beginning of Parashath Hukath by the Noam Elimelech. There he goes on to explain (according to Rashi according to Rabeinu Mosheh haDarshan) that the reason the parah adumah is considered a hok, generally a law with no known reason, is because it is the only mitzwah that does not correspond to a particular part of the the body, neither the 248 limbs nor the 365 sinews. Why doesn't it correspond to a part of the body? Because its sole purpose was to educate the masses about the reality of Teshuvah. In this explanation even the sin of the golden calf only came about in order to create a situation that the mitzwah of the Red Heifer would be revealed such that we all could reveal the great mitzwah of Teshuvah.