Nakanishi K, et al. - This research was formulated in order to gauge the effects of forced deep breathing on peak blood velocity in the superficial femoral vein (PBVFV), which served as a surrogate measure of the efficacy of thromboprophylaxis against deep-vein thrombosis (DVT), in patients with plaster cast immobilization of the lower limb. A prominent increase was noted in PBVFV among patients with plaster cast immobilization of the lower limb in both supine and sitting positions due to forced deep breathing. In order to develop a new physical prophylaxis for DVT, prospective trials were warranted.