Effectiveness of Visual Perceptual Learning on Inter-Therapist Reliability of Lumbar Spine Mobilization

ABSTRACT
Manual therapy is a widely used treatment technique among physical therapists and is effective in the treatment of musculoskeletal disorders.  The theory behind the selection of the appropriate grade of mobilization dictates that proper assessment of the stiffness or resistance of a joint must occur in order to assign the therapeutic intensity. Educational models to teach this theory have shown variable success.  In numerous studies, the reliability of clinicians' assessment of stiffness and movement assessment is poor.  This present study involved a pre-perceptual educational model designed for 22 practicing physical therapists that performed Grade I, II, III and IV mobilizations on two asymptomatic volunteers.  Therapists stood on a Kistler force plate™ during mobilization, and mobilization forces were calculated based on the magnitude of reduction of the therapist's ground reaction forces during mobilization.  The five maximal force values for each grade and each subject were used for Intraclass correlation (ICC) analysis of inter-therapist reliability.  The ICC value was -0.05 for Grade I mobilizations, -0.05 for Grade II mobilizations, -0.04 for Grade III, and -0.03 for Grade IV.  The results for a pre-perceptual educational model are similar to past studies and indicate poor inter-therapist reliability in the performance of all grades of manual therapy mobilization.