Which statement about assigning a motor level for spina bifida is true?

Which statement about assigning a motor level for spina bifida is true?

• A. The motor level is the lowest intact functional neuromuscular segment
• B. The motor level is the most impaired side
• C. The motor level is determined by imaging only
• D. The motor level is the highest spinal segment with any movement

Answer: (A)

In spina bifida, the motor level is defined by the clinical exam of the body's myotomes. The motor level is the most caudal spinal segment that still has functional movement against gravity (typically a muscle strength of about 3/5 in the corresponding key muscles), with all segments above it functioning normally. This means you’re identifying the lowest intact functional neuromuscular segment, not the most impaired one. Imaging can show anatomy, but it cannot replace the live motor exam for determining motor level. It is not about the highest segment that can move, and it is not determined by the most impaired side.