Amazon is disregarding its own research that shows warehouse employees are facing an increased injury threat due to its focus on productivity, according to Senate investigators.Related video above: Look out for ads posing as Amazon search resultsThe Senate report released Sunday said the company forces workers to repeat the same movements hundreds, if not thousands, of times each shift, resulting in extremely high rates of injury to their muscles and joints. Amazon also forces workers to choose between following safety procedures, such as asking for help to move heavy objects, or risk discipline and potential termination for not moving fast enough, the report said.But the company insists the report intentionally distorts data, and its record shows injuries are down even while its output has increased significantly in recent years.The 160-page report, from the staff of a Senate committee headed by long-time Amazon critic Sen. Bernie Sanders of Vermont, is not …