Les facteurs de risque de troubles musculo-squelettiques(TMS) tels que les facteurs physiques, organisationnels et psychosociaux sont un défi commun pour les industries de l'assemblage automobile qui entrainent des effets indésirables sur le système et les humains. L’ergonomie a déjà été intégrée dans les systèmes de production de ces industries pour la prise en charge de la prévention des TMS. La question est de savoir si l'approche ergonomique actuelle des industries automobiles, sur la base de normes à l'entreprise et des méthodes d'observation, peut fournir une connaissance partagée des facteurs ergonomiques pour les divers intervenants et pour faciliter l'amélioration des conditions de travail. Cette étude aborde la problématique du positionnement des différents méthodes d'évaluation (utilisées par les différents intervenants) et compare les résultats et apports de chaque méthode d'évaluation. Cette thèse propose que la procédure actuelle d'évaluation des risques de TMS ne favorise pas une connaissance partagée entre les intervenants dans les industries automobiles. On constate que les évaluations par auto-questionnaire (opérateurs) sont significativement différentes de celles issues des méthodes d'observation (ergonome) et des mesures directes (analyse biomécanique). Cependant, les opinions et jugements des opérateurs concernant les facteurs ergonomiques sont importants pour faciliter la réussite d'une approche ergonomique. Un entretien structuré et systématisé, basé sur des données objectives (Video-observations ou de mesure directe) liées aux activités et stratégies des opérateurs, pourrait être une procédure appropriée pour faire progresser l'ergonomie des situations de travail. Enfin, la connaissance tirée de cette thèse souligne que la variabilité des tâches dans l’industrie automobile nécessite une approche ergonomique qui partage les connaissances des risques entre les intervenants. Dans cette approche, les attitudes et les comportements des opérateurs sont pris en compte dans les projets d’amélioration continue. De plus, la participation des intervenants devrait être intégrée afin d'améliorer la prise en compte de l'ergonomie dans la production. Une synthèse de cette thèse en Français a été fournie dans l’annexe première. / Musculoskeletal risk factors such as physical, organizational and psychosocial factors are a common challenge for the automotive assembly industries and result in adverse human and system effects. Ergonomics has already been integrated inthe production systems of such factories to eliminate work related musculoskeletal disorders (WR-MSDs). The issue is whether the current ergonomic approach of car industries, based on corporate standards and observational methods, can provide a shared knowledge of ergonomic factors for various stakeholders and facilitate ergonomic improvement. This study focuses on the positioning of the different assessment methods (used by various stakeholders), agreement between their results in evaluation of physical risk factors and the influence of intervention and improvement following ergonomic assessment. This thesis proposes that the current procedure of risk factor assessment can not provide ashared knowledge and representation of risks between stakeholders in manufacturing industries. It was found that the operators’ assessments of risk factors (self-reported questionnaire) were significantly different from those assessed by observational methods (ergonomist) and direct measurement. However, the operators’ opinions and judgments of ergonomic factors of a job are of particular importance to the success of an ergonomic approach. A structured interview based on objective data (video-observation or direct measurement) linked the activities and strategies of atrisk operators might be an appropriate procedure to advance ergonomics.The knowledge gained from this study emphasizes that the variable nature of tasks in manufacturing industries needs an ergonomic approach which shares knowledge and representation of risks between stakeholders. In such an approach, attitudes and behaviors of operators are taken into consideration in developing new intervention processes, organizational and technical remedies. Moreover, involvement of stakeholders should be integrated and this should result in improving production ergonomics.

La presente tesi si focalizza sullo studio delle determinanti e delle conseguenze del rischio sul lavoro e degli incidenti occupazionali nel mercato del lavoro. Il primo contributo (Capitolo 1) fornisce una rassegna critica all'interno di un quadro di analisi armonizzato allo scopo di evidenziare le debolezze della letteratura teorica ed empirica, che si occupa di rischio sul lavoro e dei incidenti occupazionali. Nell’ indagare le determinanti degli incidenti sul lavoro (Capitolo 2), si analizza il ruolo delle condizioni di lavoro e della sicurezza sul posto di lavoro nel ridurre la probabilità di un infortunio e la durata della relativa assenza, tema inesplorato nella limitata letteratura empirica. I nostri risultati forniscono evidenze cross-country che una maggiore sicurezza contribuisce a ridurre la probabilità che un incidente si verifichi e le corrispondenti conseguenze, in termini di giorni di assenza per infortunio. Particolare attenzione viene posta nel considerare il ruolo delle regolamentazioni sulla sicurezza e delle pratiche di organizzazione del lavoro. Il Capitolo 3 studia le conseguenze degli infortuni. Ci si concentra a determinare come un incidente possa influenzare i costi sostenuti dal lavoratori, vale a dire una riduzione delle probabilità di occupazione e perdite salariali, sia nel breve sia lungo periodo. Utilizzando i dati BHPS, si trova che, nel breve periodo, uno stato di infortunio, in seguito ad un incidente occupazionale, porta ad una maggiore probabilità di perdere il lavoro; nel lungo periodo, i lavoratori infortunati possono subire consistenti perdite salariali che possono essere evitate se il lavoratore è occupato nel settore pubblico o in imprese sindacalizzate. / This dissertation focuses on investigating the determinants and the consequences of risk at work and occupational accidents in the labour market. The first contribution (Chapter 1) provides a critical survey within an harmonized framework of analysis to highlight the weaknesses of the theoretical and empirical literature. In investigating the determinants of accidents at work (Chapter 2), we analyze the role of working conditions and safety at work in reducing the probability of accidents at work and the corresponding duration of absence, which is an unexplored issue in the limited empirically literature on risk at work and occupational accidents. Our findings provide cross-country evidence that more safety at work contributes to reduce the probability that an accident occurs and its consequences, in terms of days off from work. Particular attention is used in considering the role of safety at work regulations and of work organization practices. Chapter 3 studies the consequences of occupational injuries. We focus in determining how an accident may affect workers’ costs, namely a decline of employment probabilities and earning losses, either in the short or in the long term. Using the BHPS data, we find that, in the short term, a state of injury, following an occupational accident, leads to a higher probability of losing job; in the long term, injured workers may support significant earning losses that may vanish if they are employed in the public sector or in unionized firms.