The arms allow the force on the torso to be displaced without the use of extra energy by muscles. If arm swing is done incorrectly while walking or running, extra energy will be used by your core muscles to keep proper posture. This extra energy is inefficient. A study conducted on people while walking and running showed that the swing of the arm is powered by the movement of the legs and not by the muscles in the shoulders, and that the arms act as a “passive damper” reducing head and torso rotation (Pontzer, Holloway, Raichlen, & Lieberman 2009).
Comments
Very interesting. However, I
Very interesting. However, I do think the sentence "This extra energy is inefficient" could have been worded differently.
"this extra energy is
"this extra energy is inefficient." i think you shoukd have made this sentence part of the last one with a ;
Concluding sentence.
I feel that a summarizing, concluding sentence tieing together the experimental findings and the aformentioned efficiency of arm swinging would improve the paragraph.