Mechanical Diagnosis and Therapy

Mechanical Diagnosis and Therapy is a classification-based approach that uses standardized clinical examination to identify patient subgroups and guide exercise-based treatment and self-management. Derangement syndrome is described as the most common MDT classification. Research support for McKenzie shift correction is sparse, appearing primarily in case reports rather than controlled trials. Systematic reviews suggest MDT may help selected chronic spinal pain subgroups, but evidence remains inconclusive outside chronic low back pain and certain populations. MDT classifies patients by symptom and mechanical responses during repeated movements or sustained positions. The McKenzie Method addresses lateral shifts with a shift correction technique that physically guides the patient's body back toward neutral alignment. MDT treatment follows four overlapping stages: symptom reduction, maintenance of reduction, recovery of function, and prophylaxis. Forcing the body back to neutral in the acute disc bulge phase can provoke significant symptom flare-ups. Participants assigned to MDT receive individualized assessment and treatment based on directional preference exercise.