Scenario:
You come home from school, run up the stairs and throw your backpack on your bed. This
sequence of events took only minutes, but used joints in your ankles, knees, elbows, shoulders,
and wrists. You realize that when you threw your bag, your cell phone slid under your dresser.
You try to reach it, but you cannot seem to get your arm back far enough. Your twin sister comes
in and offers to help. She bends down, stretches and twists her arm and almost instantly, you
have your phone back.
If we all have the same general arrangement of bones and joints, why was she able to
reach the phone with ease when you did not even come close?