Which findings predict a favorable response to mechanical traction in the traction subgroup?

• A. Centralization with extension and a positive straight-leg raise
• B. Centralization with extension and a negative straight-leg raise
• C. Peripheralization with extension and a positive crossed straight-leg raise
• D. Peripheralization with extension and a positive straight-leg raise

Answer: (C)

Traction tends to help when there is nerve root irritation from a disc problem that can be relieved by unloading the spine. If extension worsens symptoms and they peripheralize—moving further down the leg—this pattern signals ongoing nerve tension from a disc source that may respond to decompression. A positive crossed straight-leg raise adds evidence of significant disc-related nerve root compression affecting the opposite side, which is particularly responsive to traction’s unloading effect. In this context, that combination best predicts a favorable response to mechanical traction. Centralization with extension suggests a different direction of symptom change and isn’t as strongly predictive here, and a negative straight-leg raise or a non-crossed positive SLR provides less corroborating evidence of a disc-related radiculopathy amenable to traction.