In grade 2 muscle pull, there is limping with severe muscle pain in the thigh, along with a slight swelling. This may take a month or two to heal. In grade 3 hamstring injuries, there is severe throbbing pain, swelling, and complete inability to walk. In this case, a conservative approach in the form of recovery exercises may not suffice, so there may be need for surgical intervention. The healing time is estimated to be around six months.