How to refresh page on back button click?

Try this... not tested. I hope it will work for you.

Make a new php file. You can use the back and forward buttons and the number/timestamp on the page always updates.

<?php
header("Cache-Control: no-store, must-revalidate, max-age=0");
header("Pragma: no-cache");
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT");
echo time();
?>
<a href="http://google.com">aaaaaaaaaaaaa</a>

Or

found another solution

The onload event should be fired when the user hits the back button. Elements not created via JavaScript will retain their values. I suggest keeping a backup of the data used in dynamically created element within an INPUT TYPE="hidden" set to display:none then onload using the value of the input to rebuild the dynamic elements to the way they were.

<input type="hidden" id="refreshed" value="no">
<script type="text/javascript">
onload=function(){
var e=document.getElementById("refreshed");
if(e.value=="no")e.value="yes";
else{e.value="no";location.reload();}
}

A more recent solution is using the The PerformanceNavigation interface:

if(!!window.performance && window.performance.navigation.type === 2)
{
    console.log('Reloading');
    window.location.reload();
}

Where the value 2 means "The page was accessed by navigating into the history".

View browser support here: http://caniuse.com/#search=Navigation%20Timing%20API

Reload the site when reached via browsers back button