A muscle cell contracts or expands when

Walking

Explanation:

A muscle cell usually contracts or expands simultaneously when one is working or doing some activities like running, exercises, house chores e.t.c

Muscles are flexible fibers that are very essential appendages for locomotion in human beings.

For muscle cells to contract, they are pulled together thereby causing tension in the muscle. When they are relaxed, they move away from one another.

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.