You are treating a patient after a meniscal root repair with…

You are treating a patient after a meniscal root repair with the following precautions from the surgeon: nonweightbearing, no resisted hamstring strenghening, no PROM past 90 degrees. Your goal is to minimize the atrophy that is suffered following knee surgery. Which of the following intervention is most appropriate to maintain strength/minimize atrophy of the quadriceps for this patient?