Exploring indicators of extremity pain of spinal source as identified by Mechanical Diagnosis and Therapy (MDT): a secondary analysis of a prospective cohort study.

Objective: To explore indicators that predict whether patients with extremity pain have a spinal or extremity source of pain.

Methods: The data were from a prospective cohort study (n = 369). Potential indicators were gathered from a typical Mechanical Diagnosis and Therapy (MDT) history and examination. A stepwise logistic regression with a backward elimination was performed to determine which indicators predict classification into spinal or extremity source groups. A Receiver Operating Characteristic (ROC) curve was constructed to examine the number of significant indicators that could predict group classification.

Results: Five indicators were identified to predict group classification. Classification into the spinal group was associated with the presence of paresthesia [odds ratio (OR) 1.984], change in symptoms with sitting/neck or trunk flexion/turning neck/when still (OR 2.642), change in symptoms with posture change (OR 3.956), restrictions in spinal movements (OR 2.633), and no restrictions in extremity movements (OR 2.241). The optimal number of indicators for classification was two (sensitivity = 0.638, specificity = 0.807).

Discussion: This study provides guidance on clinical indicators that predict the source of symptoms for isolated extremity pain. The clinical indicators will allow clinicians to supplement their decision-making process in regard to spinal and extremity differentiation so as to appropriately target their examinations and interventions.