O(n^2) String computation to find reverse words

gistfile1.js

function reverse_word(w){
	return w.split("").reverse().join("");
}

// O(n^2) Implementation
function hasreverse(string){

	var s_length = string.length;
	var words_reversed=[];	

	if(s_length < 5) {
		return -1;
	}else{
		for (var i = 2; i < s_length; i++){
			var left_characters = string.substr(0, i);
			var reverse_left_characters = reverse_word(left_characters);
			var right_characters = string.substr(i + 1, s_length);
			var word_out = '';
			var index = 0;
			for(var j = 0; j < reverse_left_characters.length; j++){				
					if(left_characters[j] && right_characters[j]){
						if(reverse_left_characters[j] === right_characters[j]){
							word_out += reverse_left_characters[j];	
							index=i;
						}else{
							break;
						}
					}				
			}

			if(word_out.length>2){
				words_reversed.push({
					word: word_out,
					at_index: index
				})
			}
		}
	}
	return words_reversed;
}

console.log(hasreverse("oracicarlrenogabgyioiygiuduliter")); //should output [{word:"car", at_index:4}]