Two employees were attaching 8"" cement hose to surface cement hole. They were in basket of JCB to make hook up. Boom was extended out approx. 20' to reach pipe at cement hole when the basket boom tipped over & fell to ground approx. 25'. They were taken to Dr. & released to work. Injured EE continued to have pain in his rib/back area. Prescribed a cortizone shot & therapy.