The Gemara does not actually say that he damages with his feet and hands. The Gemara says "d'Kayif u'Pashit." The word "Kayif" means to straighten (as in the word "Kefufim," which we say in the morning blessings, "Zokef Kefufim," which praises Hash-m for "straightening" the people who were "bent" in their sleep). The Gemara is saying that the person was folded up ("d'Kayif") in his sleep and then straightened himself ("u'Pashit"). Rashi explains that he straightened his feet. It seems that Rashi is telling us that it is more likely that a sleeping person will break an object by stretching out his feet in the middle of his sleep.

Kol Tuv,

Dovid Bloom