Jesus didn't have to touch the man - he could have just spoken words, but in touching him, he sought to heal more than just the outside condition, but to heal the condition of his heart - the loneliness and isolation and despair the man had been living in for years - isolated from family and community.  Before he is healed, Jesus touches him - Jesus enters his 'space' as is, then heals him there....  
 Matthew 8:1-4  /  Mark 1:40-45