Assessment in patients with NMD consists principally of measures of motor impairment since they are well known by clinicians and their measures do not require much equipment. The conventional treatments in patients with NMD are above-all focused on the diminution of motor impairments by maintaining or improving joint mobility, muscle strength and endurance. Nevertheless, a reduction of motor impairments does not directly lead to a higher ability in performing daily activities. Therefore, activity limitations should be measured specifically. A new scale of activity limitations was first developed in children and adults with NMD. The use of the Rasch model provided a scale to assess the fundamental psychometric qualities. Secondly, relationships between motor impairments and activity limitations were investigated to verify the assumption that reduced motor impairments do not necessarily lead to higher activity levels. Finally, to complete the investigation of psychometric qualities, a longitudinal study of the developed questionnaire was carried out to evaluate its sensitivity to change. Chapter 1 presents the development of ACTIVLIM, a Rasch-built measure of activity limitations and its validation in children and adults with NMD. ACTIVLIM is a self-reported questionnaire that assesses the difficulties adult patients and parents of affected children perceive when they or their children perform daily activities. This questionnaire originally included 126 daily activities and was submitted to 369 patients. The Rasch model selected 22 daily activities to define a linear and unidimensional measure of activity limitations in patients with NMD. The validity and the reproducibility of the results were also studied. A second section of Chapter 1 demonstrates why the measure of activity limitations in children with NMD as assessed using the ACTIVLIM questionnaire is based upon the perception of their parents. A third section of Chapter 1 compares the difficulties self-perceived by the patients with the difficulties observed by external examiners. The agreement between both measures is very good, indicating that the use of ACTIVLIM as a self-reporting questionnaire is a valid method to assess activity limitations in patients with NMD. Chapter 2 investigates the relationships between motor impairments and activity limitations as measured with the ACTIVLIM questionnaire. As the anatomical basis and pathophysiology are different from one NMD to another, the relationships between impairments and activity limitations were investigated in six main diagnostic groups and in the whole sample without diagnostic distinction. Gait speed and muscle weakness in proximal and flexor muscle groups were significantly but moderately correlated to the activity limitations, indicating that the latter cannot simply be inferred from motor impairments but should be independently measured and treated. Chapter 3 investigates the sensitivity to change of the ACTIVLIM questionnaire. As NMD are progressive disorders, it is important that the ACTIVLIM questionnaire be able to assess the change over time in the activity level of patients with NMD in order to characterize the disease course and to quantify the effects of new treatments on activity limitations in these patients. Finally, the last section discusses the results of the different chapters and presents perspectives for future research.

The purpose of the present work was to study hand impairments and manual ability in children with cerebral palsy (CP) as well as to clarify their relationship. Appraising the degree of hand impairments requires normative data to differentiate the real dysfunctions of CP children from the normal difficulties according to their age, sex, or handedness. As there is no normative data for gross manual and fine finger dexterity, a first experiment focused on the normal development of manipulative functions was conducted to establish these norms. A second experiment was carried out to develop and validate through the Rasch model a measure of manual ability in children with CP since such a measure was not yet available. The invariance of the ABILHAND-Kids questionnaire was also tested across relevant demographic and clinical subgroups of CP children. Finally, a third experiment was performed to quantify the hand impairments in children with CP and to investigate their relationship with manual ability as measured with the ABILHAND-Kids questionnaire. Hand motor impairments, markedly more prevalent than hand sensory impairments, were moderately correlated with manual ability measures and predicted 58% of their variance. Consequently, manual ability cannot simply be inferred from hand impairments and should be measured and treated per se. / L'objectif de ce travail était d'étudier les déficiences de la main et l'habileté manuelle chez les enfants infirmes moteurs d'origine cérébrale (IMOC) ainsi que de clarifier leur relation. Apprécier la gravité des déficiences de la main nécessite des données normatives afin de différencier les dysfonctionnements réels des enfants IMOC des difficultés normales compte tenu de leur âge, sexe, ou latéralité. Etant donné l'absence de normes quant à la dextérité manuelle grossière et la dextérité digitale fine, une première étude a été réalisée afin d'examiner le développement normal de ces deux types de dextérité. Des normes sur les dextérités manuelle grossière et digitale fine ont ainsi pu être établies. Une deuxième étude a été effectuée afin de développer et valider à travers le modèle de Rasch une mesure de l'habileté manuelle chez les enfants IMOC. L'invariance du questionnaire ABILHAND-Kids a également testée à travers différents sous-groupes démographiques et cliniques d'enfants IMOC. Enfin, une troisième étude a été réalisée afin de quantifier les déficiences de la main chez les enfants IMOC et d'investiguer leur relation avec l'habileté manuelle. Les déficiences motrices de la main, plus prévalentes que les déficiences sensitives, étaient modérément corrélées avec les mesures d'habileté manuelle et prédisaient 58% de leur variance. En conséquence, l'habileté manuelle ne peut être simplement inférée à partir des déficiences de la main et devrait donc être mesurée et traitée pour elle-même.

The purpose of the present work was to study hand impairments and manual ability in children with cerebral palsy (CP) as well as to clarify their relationship. Appraising the degree of hand impairments requires normative data to differentiate the real dysfunctions of CP children from the normal difficulties according to their age, sex, or handedness. As there is no normative data for gross manual and fine finger dexterity, a first experiment focused on the normal development of manipulative functions was conducted to establish these norms. A second experiment was carried out to develop and validate through the Rasch model a measure of manual ability in children with CP since such a measure was not yet available. The invariance of the ABILHAND-Kids questionnaire was also tested across relevant demographic and clinical subgroups of CP children. Finally, a third experiment was performed to quantify the hand impairments in children with CP and to investigate their relationship with manual ability as measured with the ABILHAND-Kids questionnaire. Hand motor impairments, markedly more prevalent than hand sensory impairments, were moderately correlated with manual ability measures and predicted 58% of their variance. Consequently, manual ability cannot simply be inferred from hand impairments and should be measured and treated per se. / L'objectif de ce travail était d'étudier les déficiences de la main et l'habileté manuelle chez les enfants infirmes moteurs d'origine cérébrale (IMOC) ainsi que de clarifier leur relation. Apprécier la gravité des déficiences de la main nécessite des données normatives afin de différencier les dysfonctionnements réels des enfants IMOC des difficultés normales compte tenu de leur âge, sexe, ou latéralité. Etant donné l'absence de normes quant à la dextérité manuelle grossière et la dextérité digitale fine, une première étude a été réalisée afin d'examiner le développement normal de ces deux types de dextérité. Des normes sur les dextérités manuelle grossière et digitale fine ont ainsi pu être établies. Une deuxième étude a été effectuée afin de développer et valider à travers le modèle de Rasch une mesure de l'habileté manuelle chez les enfants IMOC. L'invariance du questionnaire ABILHAND-Kids a également testée à travers différents sous-groupes démographiques et cliniques d'enfants IMOC. Enfin, une troisième étude a été réalisée afin de quantifier les déficiences de la main chez les enfants IMOC et d'investiguer leur relation avec l'habileté manuelle. Les déficiences motrices de la main, plus prévalentes que les déficiences sensitives, étaient modérément corrélées avec les mesures d'habileté manuelle et prédisaient 58% de leur variance. En conséquence, l'habileté manuelle ne peut être simplement inférée à partir des déficiences de la main et devrait donc être mesurée et traitée pour elle-même.