Saskia Baltrusch

170 Chapter 6 (TAM), that was proposed by Davis (1989) [20], is an influential, validated model on consumer’s acceptance of technological innovations in various contexts. It proposes that, when users are presented with new technology, a number of factors influence their decision about how and when they will use it. It also defines ‘perceived benefits’ as a major determinant of the intention to use wearable technology. In an elaborate review [21], Kalantari (2017) defines further categories to be considered in the model, such as perceived comfort and perceived compatibility, as both have confirmed impact on end-users’ attitude and their usage intentions. This model supports our suggestions to improve perceived efficacy and acknowledges that increased perceived efficacy and perceived comfort would enhance user satisfaction of the SPEXOR exoskeleton. Potential approaches to reach these objectives could be an increase of support delivered by the device or design adaptations to increase the perception of support, and to decrease the weight and dimensions of the exoskeleton. Increasing the end-users’ intention to use the exoskeleton, would allow progression from a research device to a wearable device that can be implemented in the working environment. Subgroup analysis on the effect of the SPEXOR exoskeleton in people with and without a history of low-back pain showed that the observed main effects of exoskeleton use for both objective and subjective measures, were mostly due to an effect in the low-back pain group. While perceived task difficulty did not show an interaction effect, two objective performance outcomes and local discomfort in the low back showed a clear interaction effect of exoskeleton use and group. People with low back pain showed a higher increase in performance in static forward bending and a larger decrease in wide stance performance than people in the healthy group. Additionally, people with low-back pain reported larger reduction in discomfort when using the device than people without low-back pain. This stands to reason, considering that people in the pain group reported current pain before the start of the measurement, compared to the healthy group. The interaction effects between exoskeleton use and group imply a potentially bigger effect of wearing the SPEXOR exoskeleton in people with a history of low-back pain. This indicates that such an exoskeleton would be more applicable in secondary prevention compared to primary prevention. Still, the average pain level of the participants in the pain group was rather low (3.5).