// add new widget called repeatHeaders
$.tablesorter.addWidget({
    // give the widget a id
    id: "repeatHeaders",
    // format is called when the on init and when a sorting has finished
    format: function(table) {
        // cache and collect all TH headers
        if(!this.headers) {
            var h = this.headers = [];
            $("thead th",table).each(function() {
                h.push(
                    "" + $(this).text() + ""
                );

            });
        }

        // remove appended headers by classname.
        $("tr.repated-header",table).remove();

        // loop all tr elements and insert a copy of the "headers"
        for(var i=0; i < table.tBodies[0].rows.length; i++) {
            // insert a copy of the table head every 10th row
            if((i%5) == 4) {
                $("tbody tr:eq(" + i + ")",table).before(
                    $("").html(this.headers.join(""))

                );
            }
        }
    }
});