sort by best latest
Probably to help balance the body. As a leg moves forward, the arm on the same side swings backward.
You can help the HubPages community highlight top quality content by ranking this answer up or down.
For balance and keep your center of gravity from deviation
Copyright © 2017 HubPages Inc. and respective owners. Other product and company names shown may be trademarks of their respective owners. HubPages® is a registered Service Mark of HubPages, Inc. HubPages and Hubbers (authors) may earn revenue on this page based on affiliate relationships and advertisements with partners including Amazon, Google, and others.
Copyright © 2017 HubPages Inc. and respective owners.