BACKGROUND: The importance of postoperative stability when considering surgery on the foot and ankle cannot be overestimated. To our knowledge, no literature exists to describe the radiographic sagittal plane motion with varying types of immobilization devices. The purpose of this study was to evaluate the sagittal plane range of motion allowed in different types of boots in comparison to fiberglass cast treatment on normal human subjects. MATERIALS AND METHODS: Ten healthy volunteers without preexisting foot and ankle pathology were chosen for the study. Five types of immobilization were selected for testing, including 4 off-the-shelf braces and a fiberglass cast. Maximum dorsiflexion and maximum plantarflexion lateral radiographs were taken without any immobilization and in the fiberglass cast and all walkers. RESULTS: The mean range of motion in a fiberglass cast was 8.4 degrees (SD, 4.3 degrees); FP Foam Walker, 16 degrees (SD, 6.7 degrees); XP Pneumatic Walker, 15.4 degrees (SD, 5.6 degrees); Donjoy Max Walker, 19.1 degrees (5.4 degrees); and the SP Walker, 39 degrees (SD, 10.7 degrees). The cast was noted to have a significantly greater limitation of sagittal plane motion compared to all other forms of immobilization (p < 0.05). CONCLUSION: Sagittal plane motion is restricted significantly more with a fiberglass cast compared to the FP Foam Walker, and XP Pneumatic Walker, Donjoy Max Walker, and the SP Walker. Therefore, in patients whom maximum restriction of sagittal plane motion is required, use of a fiberglass cast offers superior control.