THE REACHING AND HAND TO MOUTH METHOD FOR AN INSTRUMENTAL FUNCTIONAL ASSESSMENT OF THE UPPER LIMB

INTRODUCTION and AIM The kinematic analysis of the upper-limb motion experienced, during the last decades, several different methods and setups for the kinematic data acquisition. However, to the best of authors' knowledge, no instrumental kinematic procedure for the assessment of the upper-limb functional ability has been up to date defined for routinely-clinical use. The lack of methodological works about shared protocols for standard acquisition (i.e. conveniently usable sampling procedures according to models) and analysis (i.e. comparable data evaluation) of UL movements can be also reckoned as the main cause of the to-date unavailability of kinematic control data from healthy subjects. The objective of this study is therefore two-fold: first, a procedure for upper-limb data acquisition and evaluation in selected functional tasks, the Reaching and Hand-to-Mouth method, is tested according to sensitivity and reliability criteria in order to be deployed for routinely-clinical use as a kinematic examination protocol. Second, evaluated data are used to populate a wide control group of healthy subjects to be used in the assessment of patients' upper-limb motor control and functional ability. PATIENTS/MATERIALS and METHODS The Reaching and Hand-to-Mouth, which is a method that had been developed at the Movement Analysis Lab at Villa Beretta Rehabilitation Hospital for functional assessment, [1] has been applied to examine a group of 42 healthy subjects. They were evaluated for both the dominant and nondominant arm motor performance. Sixteen of them were reevaluated after 2 weeks to allow test-retest repeatability analysis. Mean values of times of movement execution, joint angles and trajectories of bony landmarks were computed for each subject. Movement repeatability and smoothness were also evaluated for motor control assessment. Data evaluation was considered for reliability (data consistency over time and among subjects) and sensitivity (discrimination capability among different evaluation clustering of data, i.e. age subjects' groups, limb dominance and tasks). RESULTS The kinematic data analysis show notable test-retest repeatability in all tasks. Regardless the task, no statistically-significant differences between the dominant and nondominant limb are observed. Significant differences are present between elderly and young subjects in the measures related to the ability for coordination. Results suggest the presence of lower motor control abilities in old subjects compared to the young ones, especially at low movement speeds. DISCUSSION and CONCLUSIONS The sensitivity of the method against changes in the movement control is further demonstrated. Interestingly enough, the evidence of a selective coordination deficit for the elderly subjects is displayed consistently with the results of other studies reported in the literature [3]. Test-retest repeatability, which had already been proved to be high in a small group of subjects [1], is consistently confirmed. Further, the applicability of the method has been demonstrated over 15 years of use in patients affected by different pathologies (Stroke, TBI, Parkinson and Friedreich). Particular applications refer to the use of the method to test the effect of the Bilateral Subthalamic Deep Brain Stimulation [2] and to verify the efficacy of treatments like the Constraint Induced Movement Therapy [1]. In conclusion, the proposed method, combined with control data from healthy subjects, appears to be a suitable and reliable tool for functional routinely assessment of the upper limb in the clinical environment. REFERENCES [1] Caimmi M, Carda S, Giovanzana C, Maini ES, Sabatini AM, Smania N, Molteni F: Using kinematic analysis to evaluate constraint-induced movement therapy in chronic stroke patients. NNR 2008, 22(1):31-39. [2] Molteni F, Caimmi M, Maini ES, Sabatini AM, Rossini M, Franzini A: Instrumental kinematic approach for assesing upper limb motor control in Parkinson's Disease: case report. Movement Disorders 2002, 17(5):31-39. [3] Seidler RD, Alberts JL, Stelmach GE. Changes in multi-joint performance with age. Motor Control 2002;6:19-31.