John Strain: The 6th Social Muscle, Common Ground by The Voice Staff | May 5, 2018 | Game Plan For Life, Skip Hall Game Plan For Life John Strain: The 6th Social Muscle, Common Ground Play Episode Pause Episode Mute/Unmute Episode Rewind 10 Seconds 1x Fast Forward 30 seconds 00:00 / 30:48 Subscribe Share RSS Feed Share Link Embed Today Skip is talking with John Strain. John Strain discusses the 6th social muscle, common ground.