Sensorized gloves allow the measurement of all hand kinematics that are essential for daily functionality. However, they are scarcely used by clinicians, mainly because of the difficulty of analyzing all joint angles simultaneously. This study aims to render this analysis easier in order to enable the applicability of the early detection of hand osteoarthritis (HOA) and the identification of indicators of dysfunction. Dimensional reduction was used to compare kinematics (16 angles) of HOA patients and healthy subjects while performing the tasks of the Sollerman hand function test (SHFT). Five synergies were identified by using principal component (PC) analyses, patients using less fingers arch, higher palm arching, and a more independent thumb abduction. The healthy PCs, explaining 70% of patients’ data variance, were used to transform the set of angles of both samples into five reduced variables (RVs): fingers arch, hand closure, thumb-index pinch, forced thumb opposition, and palmar arching. Significant differences between samples were identified in the ranges of movement of most of the RVs and in the median values of hand closure and thumb opposition. A discriminant function for the detection of HOA, based in RVs, is provided, with a success rate of detection higher than that of the SHFT. The temporal profiles of the RVs in two tasks were also compared, showing their potentiality as dysfunction indicators. Finally, reducing the number of sensors to only one sensor per synergy was explored through a linear regression, resulting in a mean error of 7.0°.

The early and objective detection of hand pathologies is a field that still requires more research. One of the main signs of hand osteoarthritis (HOA) is joint degeneration, which causes loss of strength, among other symptoms. HOA is usually diagnosed with imaging and radiography, but the disease is in an advanced stage when HOA is observable by these methods. Some authors suggest that muscle tissue changes seem to occur before joint degeneration. We propose recording muscular activity to look for indicators of these changes that might help in early diagnosis. Muscular activity is often measured using electromyography (EMG), which consists of recording electrical muscle activity. The aim of this study is to study whether different EMG characteristics (zero crossing, wavelength, mean absolute value, muscle activity) via collection of forearm and hand EMG signals are feasible alternatives to the existing methods of detecting HOA patients’ hand function. We used surface EMG to measure the electrical activity of the dominant hand’s forearm muscles with 22 healthy subjects and 20 HOA patients performing maximum force during six representative grasp types (the most commonly used in ADLs). The EMG characteristics were used to identify discriminant functions to detect HOA. The results show that forearm muscles are significantly affected by HOA in EMG terms, with very high success rates (between 93.3% and 100%) in the discriminant analyses, which suggest that EMG can be used as a preliminary step towards confirmation with current HOA diagnostic techniques. Digit flexors during cylindrical grasp, thumb muscles during oblique palmar grasp, and wrist extensors and radial deviators during the intermediate power–precision grasp are good candidates to help detect HOA.

Eye-tracking technology can assist researchers in understanding motivational decision-making and choice processes by analysing consumers’ gaze behaviour. Previous studies showed that attention is related to decision, as the preferred stimulus is generally the most observed and the last visited before a decision is made. In this work, the relationship between gaze behaviour and decision-making was explored using eye-tracking technology. Images of six wardrobes incorporating different sustainable design strategies were presented to 57 subjects, who were tasked with selecting the wardrobe they intended to keep the longest. The amount of time spent looking was higher when it was the chosen version. Detailed analyses of gaze plots and heat maps derived from eye-tracking records were employed to identify different patterns of gaze behaviour during the selection process. These patterns included alternating attention between a few versions or comparing them against a reference, allowing the identification of stimuli that initially piqued interest but were ultimately not chosen, as well as potential doubts in the decision-making process. These findings suggest that doubts that arise before making a selection warrant further investigation. By identifying stimuli that attract attention but are not chosen, this study provides valuable insights into consumer behaviour and decision-making processes.

The emergence of new display technologies can change the perception of product design features and their assessment. Previous studies are limited to comparisons between a few technologies; the real product is considered only occasionally. This work compares the perceptions of 10 design features in two household products, shown by five display technologies (image rendering, 360° rotation, and augmented, immersive, and non-immersive virtual reality), and also with the real product. Results show that the 360° rotation provides the best perception for the most important features. However, the perception of aesthetic features is better achieved with i_VR. Other global results vary depending on the product. Finally, interaction with the real product shows a quite different perception for many features. The results contribute to the understanding of product perceptions influenced by different displays, comparing them with perceptions generated through real interaction. It is expected that the conclusions will be used to optimize the presentation of product features.

This study explores the application of Eye-Tracking technology for the ergonomic evaluation of assistive device usability. Sixty-four participants evaluated six jar-opening devices in a two-phase study. First, the participants’ gaze was recorded while they viewed six rendered pictures of assistive devices, each shown in two different versions: with and without rubber in the grip area. Second, the participants physically interacted with the devices in a hands-on usability task. In both phases, participants rated the devices according to six usability affordances: robustness, comfort, easiness to grip, lid slippery, effort level, and easiness to use. Eye-Tracking metrics (fixation duration, number of fixations, and visit duration) correlated with the on-screen ratings, which aligned with ratings after using the physical devices. High ratings in comfort and effort level correlated with more visual attention to the grip area, where the rubber acted as key signifier. Heatmaps revealed the grip area as important for comfort and easiness to use and the lid area for robustness and slipperiness. These findings demonstrate the potential of Eye Tracking in usability studies, providing valuable insights for the ergonomic evaluation of assistive devices. Moreover, they highlight the suitability of Eye Tracking for early-stage design evaluation, offering objective metrics to guide design decisions and improve user experience.