Monitoring foot prostheses is essential, as their performance impacts users’ daily lives. Fiber Bragg Grating (FBG) sensors represent a gold standard in monitoring applications, but traditional optoelectronic units are too cumbersome for wearable applications. This research addresses this issue by using a lightweight and compact optoelectronic unit and developing a compensation algorithm to overcome the signal drift phenomena caused by the light source instability. The proposed method uses an FBG as a reference to provide the algorithm with information on the signals drift. The developed algorithm is based on the assumptions of linearity among drift in different detection channels and the absence of drift at the initial time instant. The compensation variable was experimentally identified and validated. Experimental validation through temperature tests showed the algorithm reduces the drift error by 60%. Finally, mechanical tests were conducted on a foot prosthesis equipped with two FBGs: one used as a reference and the other for strain sensing. An electrical strain gauge was used to validate the FBG-based sensing system. The results of the mechanical tests indicate the possiblity to monitor a foot prosthesis using FBGs. The FBG and strain gauge measurements comparison aligns with previous studies where high-performance optoelectronic units were used.

Accurate monitoring of classical dance movements, such as the demi plié and grand plié, is crucial for understanding postural dynamics and preventing injuries. In this work, the execution of the above-mentioned ballet exercises performed by one professional ballet dancer and nine amateurs is analyzed. The monitoring system consists in a 3D-printed wearable insole based on an optical fibre with eight fiber Bragg grating (FBG) sensors, employed to detect pressure changes and displacements of the center of pressure. In addition, standardized dimensionless indices (asimmetry index and time in boundary) are introduced and used for the evaluation of both asymmetries and a quantitative understanding of postural stability and muscle control during performance. The results prove that the FBG insole can detect pressure variations with high sensitivity (0.5-0.8 pm/kPa), showing significant differences between demi plié and grand plié in terms of maximum pressure (28.1 kPa × m²/kg for demi plié and 46.3 kPa × m²/kg for grand plié), and center of pressure stability. The FBG-based insole tailored for ballet dance activity and allowed comparison of the performance of the amateurs with the one of the professional dancer, and to identify potential errors during the execution of the exercises (e.g., heel lifting). The implemented methods and the obtained results allow to evaluate improvement solutions for training, readjust preparation and, in the future, identify possible injury sources.

Running-specific prostheses are widely used in Paralympic sport and their performance assessment under real running conditions requires wearable monitoring systems capable of capturing both prosthesis dynamics and athlete kinematics. Existing solutions have been validated in laboratory settings and short trials, leaving open challenges related to autonomy, robustness, and applicability to prolong outdoor running. This study aimed to design and evaluate a wearable IMU-based monitoring system for assessing prosthesis dynamics and athlete kinematics during long-distance running. Four IMU sensors mounted on prosthetic blades and sockets were deployed, addressing practical constraints of battery life, memory, and outdoor robustness. The system was tested during a 35 km trail running race by a former Paralympic athlete with bilateral transtibial amputation. The race course was segmented into nine slope-based sectors, and stride-level metrics, including impact acceleration, vibration peak, damping ratio, and damped natural frequency, were extracted from blade-mounted IMU data and compared across sectors using non-parametric statistics and effect size measures. The results suggest that the proposed system may capture meaningful variations in prosthesis dynamics across different running conditions, with moderate to large effect sizes observed for most metrics. These preliminary findings support the feasibility of the proposed approach for in-field prosthesis monitoring.

This systematic review investigates the state of the art of smart fasteners and smart washers. The collected documents were systematically classified, focusing on fasteners and washers equipped with embedded sensors capable of detecting flaws, corrosion, cracks, or monitoring features like structural response, applied load, and preload. The review emphasizes sensor technologies rather than devices made from smart materials. A total of 148 documents were found through electronic databases, of which 32 were thoroughly analyzed and categorized into 5 categories depending on the sensing capabilities, actuating capabilities, ability to transmit data, and their combinations. The analysis showed that most devices incorporate piezoelectric materials as sensing or actuation elements, primarily aimed at detecting fastener loosening or monitoring preload and load in fastened joints. Despite progress, several challenges limit industrial adoption, including sensor integration affecting bolt integrity, durability and calibration issues, and high costs. Few studies address scalability or measurement performance, highlighting the need for reliable, low-cost, and industrially scalable solutions.