Spasticity scales present poor metrologic qualities, especially concerning reliability. It allows qualitative assessement without distinction of neural and non-neural component. In 2005, the SPASM consortium published recommandations for promoting the developpement of instrumented devices devoted to spasticity assessment, recommandations renewed recently in an european consensus. The MSPMI (Medical Spastic Patient Machine Interface MSPMI) has been created in the UMR 7338 in Compiègne, designed for the study of triceps surae spasticity. The study MSPMI aims to measure the metrologic properties of this new tool. We present here the preliminary results on the first 15 patients.

Interventional monocentric study with minimal risks and constraints conducted on the Nantes University Hospital. The inclusion criterion was spasticity defined as a minimal score of 1 on the modified Ashworth scale. 25 ankles were evaluated (15 subjects). Each patient was evaluated by two raters during the same session. The evaluation included passive stretch of the triceps surae according to 6 experimental conditions. The collected parameters were the Ashworth and Modified Tardieu scales and 25 kinematic, kinetic, electromyographic and mechanical parameters given by the MSPMI. Inter-observer reliability was evaluated by measuring an intra-class correlation coefficient (ICC) and the concurrent validity by a Spearman correlation test with a significance threshold set at 5%

Sixteen of the 25 parameters have good inter-rater reliability (ICC>0.6) and 7 of them have an ICC>0.8. At intermediate speed, 56% of the parameters are significantly correlated to the modified modified Ashworth and Tardieu scales. Correlations are mostly moderate to good. The work variability index has an ICC of 0.85 and a good to moderate significant correlation at the clinical scales.

The preliminary results of the IIMPS study are encouraging. The rest of this work will complete the study of the secondary evaluation criteria.