Little robust evidence exists for appropriate venous thromboembolism prophylaxis following lower leg injury that requires cast immobilisation. We propose a randomised controlled trial to compare low dose aspirin, an intermittent pneumatic compression (IPC) device to fit under the cast plus aspirin, or a new oral anticoagulant (rivaroxaban) alone. A feasibility trial is required to assess whether this study can be carried out in a single centre and if the IPC device is an acceptable option in this setting. A total of 70 patients aged 18 to 70 years, presenting to Wellington Hospital and requiring a non-weight bearing cast for a lower limb injury will be asked to trial an IPC device for the duration of their non weight-bearing period. They will also be given aspirin. Data will be gathered about device usage, comfort and any side effects relating to its use.