Saskia Baltrusch

205 Chapter 8 1 Introduction As one of the most common health reasons for work absence [1], affecting 75-85% of workers at some point in their lifetime [2], low back pain (LBP) continues to be an industrial health problem worldwide [3]. Risk factors contributing to an incidence of LBP are known to be multifactorial [4], including biomechanical, psychosocial and individual factors [5,6]. Exoskeletons have been introduced in the industrial environment [7] in order to reduce biomechanical work-related risk factors, such as high mechanical load due to frequent lifting and forward bending [5,8,9]. Several studies have shown efficacy of different passive exoskeletons to decrease spinal loading during controlled lifting, bending, and static holding tasks [10-15]. One of these devices is the SPEXOR exoskeleton [14], which has shown positive effects on functional performance [16] and metabolic costs during lifting [17]. This exoskeleton was used for the present study. A challenge when introducing exoskeletons in the actual working environment is the acceptability of the device to users. Consumer’s acceptance of technological innovations is described in the Technology Acceptance Model (TAM) [18]. It comprises variables that explain end-users’ behavioural intentions and the individuals’ acceptance of technology. According to this model, major determinants of accepting new technology are perceived ease-of-use and perceived usefulness, indicating that the model deals with end-users’ beliefs. This implies that potential end-users need to be involved when developing and evaluating new devices to reach high acceptability. Such a user-centred approach improves user satisfaction [19] and increases usability and functionality [20]. To collect end-users’ beliefs on the usability and acceptability of an exoskeleton at work, talking to end-users about their working environment is essential. Psychosocial factors at work, such as work pace, job content and job satisfaction [21], might influence the acceptability of introducing new technology at work. Therefore, knowledge on the effect of exoskeletons on such psychosocial factors is valuable for successful design and implementation of the device. An important determinant of whether new technology will be acceptable to potential users is its effect on their self-efficacy [18]. According to Bandura 8