Answer: no. A player or creature knocked prone has several penalties assigned to it:
A prone attacker has a –4 penalty on melee attack rolls and cannot use a ranged weapon (except for a crossbow). A prone defender gains a +4 bonus to Armor Class against ranged attacks, but takes a –4 penalty to AC against melee attacks.
Standing up is a move-equivalent action that provokes an attack of opportunity. (Citation)
Normally, for a standing creature or player, five-foot step avoid the AoO. But a little digging turns up this:
You can crawl 5 feet as a move action. Crawling incurs attacks of opportunity from any attackers who threaten you at any point of your crawl. A crawling character is considered prone and must take a move action to stand up, provoking an attack of opportunity. (Citation)
Basically: if you can only move five feet because of a condition, then you can’t make a five foot step, and you incur AoOs.