Which orthosis is used for sacral S1-S2?

• A. SMO or FO
• B. KAFO
• C. AFO
• D. RGO

Answer: (A)

When the lesion is at the sacral level (S1–S2), the knee and hip function are typically relatively preserved, so the brace needs to focus on the foot and ankle rather than proximal joints. The goal is to stabilize the foot and provide proper alignment without restricting knee movement or adding bulk.

A supra-malleolar orthosis (SMO) or a simple foot orthosis (FO) does exactly that. SMO wraps around just above the ankle to control hindfoot alignment and provide mediolateral stability, helping with foot position and gait mechanics while still allowing natural ankle motion. A basic FO offers foot-level support for milder deformities. Both are lighter, more growth-friendly options appropriate for sacral-level spina bifida, where extensive knee–hip braces aren’t necessary.

In contrast, devices like a reciprocating gait orthosis (RGO) or knee-ankle-foot orthoses (KAFO) are chosen when higher-level motor impairment affects the knee or hip, requiring more proximal stabilization. An ankle-foot orthosis (AFO) focuses mainly on the ankle and may be less ideal if a child benefits from the broader hindfoot control that an SMO provides in this group.