Pain interference may be an important link between pain severity, impairment, and self-reported disability in participants with wrist/hand pain.

STUDY DESIGN: Cross-sectional. INTRODUCTION: Pain severity, sensory and motor impairment, and psychological (distress and anxiety) and social factors have previously been related to self-reported disability in persons with wrist and hand pain. PURPOSE OF THE STUDY: The purpose of this study to determine the relative contribution of pain severity, measures of impairment (sensory and motor function), psychosocial factors, and pain interference on self-reported disability experienced by persons with heterogeneous orthopedic injuries and conditions of the wrist and hand. METHODS: Measures of disability and pain severity as well as measures of sensory (pressure pain thresholds, joint position sense), motor (grip strength, Purdue pegboard), and cognitive performance (Stroop test) and psychosocial variables related to pain and participation (West Haven-Yale Multidimensional Pain Inventory) were administered to 60 participants with wrist and hand pain. Pearson product correlations controlled for age and sex, and multiple linear regression was performed to determine the relationship between measures of impairment, pain severity, psychosocial variables, and pain interference with self-reported disability assessed with the Disability of Arm, Shoulder and Hand (DASH) questionnaire. RESULTS: The best-fitting regression model with DASH scores entered as the dependent variable (F4,50 = 28.8, P < .01) included MPI Pain Interference (ß = -0.54), Life Control (ß = -0.16), Purdue pegboard scores (ß = -0.32), and Stroop test times (ß = 0.21). Pain Interference had the strongest correlation with self-reported disability (adjusted R2 = 0.67, P < .01). CONCLUSION: Pain interference appears to be an important factor explaining the link between impairment, pain severity, and self-reported disability. Addressing pain interference may be important to improve outcomes in this population.

Left Right Judgement Task and Sensory, Motor, and Cognitive Assessment in Participants with Wrist/Hand Pain.

The Left Right Judgement Task (LRJT) involves determining if an image of the body part is of the left or right side. The LRJT has been utilized as part of rehabilitation treatment programs for persons with pain associated with musculoskeletal injuries and conditions. Although studies often attribute changes and improvement in LRJT performance to an altered body schema, imaging studies suggest that the LRJT implicates other cortical regions. We hypothesized that cognitive factors would be related to LRJT performance of hands and feet and that sensory, motor, and pain related factors would be related to LRJT in the affected hand of participants with wrist/hand pain. In an observational cross-sectional study, sixty-one participants with wrist/hand pain participated in a study assessing motor imagery ability, cognitive (Stroop test), sensory (Two-Point Orientation Discrimination, pressure pain thresholds), motor (grip strength, Purdue Pegboard Test), and pain related measures (West Haven Yale Multidimensional Pain Inventory) as well as disability (Disability of the Arm, Shoulder and Hand). Multiple linear regression found Stroop test time and motor imagery ability to be related to LRJT performance. Tactile acuity, motor performance, participation in general activities, and the taking of pain medications were predictors of LRJT accuracy in the affected hand. Participants who took pain medications performed poorly in both LRJT accuracy (p=0.001) and reaction time of the affected hand (p=0.009). These participants had poorer cognitive (p=0.013) and motor function (p=0.002), and higher pain severity scores (p=0.010). The results suggest that the LRJT is a complex mental task that involves cognitive, sensory, motor, and behavioural processes. Differences between persons with and without pain and improvement in LRJT performance may be attributed to any of these factors and should be considered in rehabilitation research and practice utilizing this task.