My thinking is: trip by itself is too general; trip over something is a common expression when your emphasis is on something; trip oneself as one leg gets in the way of the other or the emphasis is on a fact that someone was losing leg coordination or balance because of nervousness or clumsiness to create a comedy effect.
http://conjugator.reverso.net/conjugation-english-verb-not%20trip%20oneself.html
Yes, "clearing" itself is sufficient, no need to add "space".
