Knee injuries are increasing in the Netherlands, while many physiotherapists are leaving the profession due to high workloads and limited career growth, highlighting a growing gap in rehabilitation services. Through literature research and qualitative interviews, the rehabilitation process, patient challenges, biomechanics, and emotional adaptations after injury were explored. A stakeholder analysis and patient journey mapping revealed that a major barrier to recovery is the misalignment between physical and psychological rehabilitation, known as parallel recovery.
Further research into existing knee wearables and competitor analysis indicated a market gap. While current solutions focus on either physiological or biomechanical measures, few integrate both to address parallel recovery. With the rise of E-health technologies and constrained healthcare access, moving the patient more to home and self management, a system promoting synchronized physical and mental rehabilitation is viable.
Based on these insights, the project scope shifted towards developing a system that enhances parallel recovery using actionable sensor data. Three design directions were developed, with the final concept being Symphysis. Symphysis is a product-service system that detects physiological responses in relation to knee movement through a sensor kit combined with a mobile app and therapist dashboard. It enables patients and physiotherapists to identify emotional challenges during rehabilitation through a unique feedback loop.
The system uses three wearable modules placed on the thigh, shin and wrist , integrating heart rate (PPG), galvanic skin response (GSR), and inertial measurement unit (IMU) sensors. By analysing changes in heart rate variability, skin conductance, range of motion, and movement biomechanics, Symphysis provides insights into how psychological states influence movement patterns. The wearable connects via Bluetooth Low Energy (BLE) to an app that visualizes the data for both patients and therapists, supporting live session tracking, daily monitoring and telerehabilitation.
To test the concept, a functional prototype was developed and evaluated with nine healthy participants. Participants completed three conditions: resting baseline, squats without cognitive load, and squats with a cognitive load (counting backwards in 7s).
Paired sample T-tests showed a significant increase in GSR (P = 0.038, d = 0.83), internal/external rotation range of motion (P = 0.045, d = 0.28), and velocity (P = 0.049, d = 0.17) under cognitive load. Participants also took significantly longer to complete exercises under cognitive load (P = 0.021, d = 0.96), indicating clear effect of the cognitive load, but the differences in time allowed participant use different adaptation strategies, which made comparison more difficult.
These results suggest that Symphysis can detect emotional influences on movement. However, sensor reliability, particularly in the wrist module, needs improvement. Future work should refine the hardware, set a fixed exercise pace to minimize adaptation strategies, and conduct further validation before drawing conclusions and beginning clinical trials.

‘Sliders’ are plastic pucks attached to the leather suit of a motorcycle racer, whose knees come in active contact with the tarmac during cornering.
The exact location of these contact points are influenced by the rider’s body position, which is highly personal for each rider due to their anthropometry and riding techniques and styles.

A new slider attachment system called the ‘Damen Grid System’ is tailored to the exact active tarmac contact points of the rider, by 3D-scanning the rider in their personally used body positions. A contact point research was conducted with professional world championship riders, to gain insight into the variables that influence the ideal position of the slider on a rider's suit. Extensive context and user research forms the base of designing a new, complementary attachment system and implementing the tailored positioning.

The system and its locking mechanism were designed to address the shortcomings of traditionally used Velcro attachment systems, by providing a more secure, precise and consistent placement solution.

By ensuring that the slider is always positioned in the optimal spot, it not only enhances rider safety but also protects the integrity of the leather suit, reducing wear and tear caused by incorrect placement or detachment.
The system integrates effortlessly with existing suits, maintaining both functionality and improving aesthetics and aerodynamics, while also increasing the overall durability and reliability of the racing gear.

This innovation aims to give riders confidence in their equipment, allowing them to focus on performance without worrying about potential gear failures.

Children with disabilities (CwD) experience many barriers decreasing their quality of life and hindering their development. Child therapists support CwD and parents of children with disabilities (PCwD) to participate in daily activities. However, the child therapists indicated to be missing the practical tools to also facilitate inclusive outdoor play. For this reason, the HU University of Applied Sciences Utrecht (HU) set up the Samen spelen project. The Samen spelen project found that PCwD and parents of children with typical development (PCwTD) play a role in the barriers CwD experience as there is a knowledge gap between them. This thesis was set up in collaboration with the HU to further explore the knowledge gap and the role increased parental contact can play in decreasing the barriers CwD experience.
It was found that PCwTD rarely come into contact with CwD and therefore lack the knowledge and skills to treat CwD properly and teach children with typical development (CwTD) about CwD. Additionally, mainly the differences between CwTD and CwD are perceived, preventing the normalisation of CwD.
Based on these findings, the design vision is formulated. The vision focuses on stimulating direct contact between CwD, PCwD, CwTD and PCwTD by guiding the parents to provide input for inclusive play. Followed by stimulating PCwD to help PCwTD correct the children during inclusive play and highlighting the similarities between the children.
Based on this vision, de Voelvlek is designed. The Voelvlek consists of a sensory rug, abstractly shaped balls called ‘monstertjes’ and play cards. The monstertjes are dynamic objects that stimulate spontaneous interaction between PCwD and PCwTD and stimulate bystanders to join the play. The parents can mix and match the play cards to facilitate inclusive play ideas for their children. By discussing the common interests of the children for the play, PCwTD learn about the similarities between CwD and CwTD. When the children are playing the PCwTD can continue this learning process through observation and the questions on the play cards. The play cards use different kinds of questions to stimulate parental interaction and help PCwTD reflect on their behaviour towards CwD and PCwTD.