By: 30 October 2019
‘A personalised solution is the future in the field of prosthetics and orthotics’

OPN talk to Dr Elena Seminati, a lecturer in clinical biomechanics at the University of Bath and research associate working on rehabilitation for the Centre for the Analysis of Motion, Entertainment Research and Applications (CAMERA)

OPN: Tell us a little about your background and education and your current role at the University of Bath?

ES: I joined the University of Bath in September 2014 as a Teaching Fellow. Since November 2014 I have been a research associate within the Sport, Health and Exercise Science Research Group. Prior to that I obtained the Laurea degree (BSc plus MSc) in Biomedical Engineering (2007) from Politecnico di Milano and a PhD degree in Human Physiology (2010) from Università degli Studi di Milano. I remained in Milan to undertake two post-doctoral research positions (2010-2014), working on human locomotion and injury prevention in sport.

I am interested in the biomechanics of human motion, especially for clinical, sport and injury prevention applications. My previous research has been focused on the relationship between energetics and mechanics of different forms of locomotion and sports. I worked on shoulder injury prevention in volleyball players, biomechanics of cycling, pathological locomotion in osteoarthritis-affected patients and cervical spine injury prevention in rugby activities.

In 2016, I joined the Centre for the Analysis of Motion, Entertainment Research and Applications (CAMERA) at the University of Bath, as a research associate working in the area of rehabilitation and in September 2018, I was appointed a lecturer in clinical biomechanics.

My research interests include lower limb amputees, pathological locomotion, sport injury prevention, musculoskeletal simulation and motion analysis. My research approach includes both experimental sessions and musculoskeletal modelling of human motion, in order to establish risk factors, prevent injuries and illness, and improve sports performance.

OPN: What was your involvement in the design of the tailor-made prosthetic liners that could help more amputees walk again?

ES: The prosthetic liner is the result of  teamwork with three different disciplines working together: Health, Mechanical Engineering and Computer Science. I’m a lecturer in clinical biomechanics and therefore I contributed to the second part of the project, mostly related to the tests with a real amputee wearing the liner. These included measurements of pressure at the interface between the skin and the liner, and classic gait analysis.

OPN: Tell us more about how you developed the liners?

ES: The idea started from thinking about personalised insoles for shoes. Since the material was comfortable and customised for the shape of the shoe and the toe, we thought about preparing something similar for amputees; something that could help the fitting of a prosthetic leg. Using a state-of-the-art scanner, which quickly captures 3D shape, we were able to precisely scan an amputee’s residuum and his socket. The scanned data was then used to create a full digital model of the residuum, which was subsequently used to design the personalised liner. The liner was then manufactured using a cryogenic machining technique. This significantly reduces production time and keeps costs down.

OPN: So far, are the outcomes promising?

ES: So far, we have been testing the liner on a single transtibial (below the knee) amputee. He seems very satisfied and he finds it very comfortable. So, I would say that the outcomes are promising. However, I would like to test the liner on a larger population of amputees with different levels of amputation and stump shape.

The quantitative outputs we have measured with gait analysis and pressure sensors seem promising, but more tests are needed to validate the use of the liner, on more people and for a longer period of time.

OPN: You use motion capture technology to monitor the patient’s gait while using the liner. How can this technology help amputees in the future?

ES: Motion capture is one of the methods we use to investigate the liner characteristics, when an amputee is wearing it. We use the motion capture system, together with force plates to check how good the gait of the amputee is, while wearing the liner. We aim to guarantee a correct gait/walking pattern, so that the lower limbs’ range of motion is symmetrical and the loads at the joints are symmetrically distributed.

We also use pressure sensors combined with the gait analysis to check that the liner is not damaging the skin of the stump of the amputee.

OPN: What is the next stage for your product development?

ES: We are planning to do some more testing with the liner and to embed some sensors within the liner. The manufacturing technique allows us to prepare very specific custom-made liners, which can accommodate the shape of the stump, but also the shape of the sensors. In particular, we are interested in measuring humidity and temperature inside the socket, where the liner is in contact with the skin of the stump of the amputee. One of the big problems for amputees is the moisture and sweating inside the socket. If we can demonstrate that our solution is able to maintain a low level of sweating/humidity, it would be a big advantage for the amputee population.

OPN: What could your research mean for the future of orthopaedics and prosthetics?

ES: Our research is aiming to improve the quality of life of the amputee population.

Although most of the amputees could benefit from our solution, we believe that the customised liner would be particularly useful during the first months after the amputation, when the stump of the amputee is continuously changing. In fact, after the surgery the stump of the amputee shrinks dramatically for the next 15-18 months, before stabilising. A personalised solution is the future in the field of prosthetics and orthotics. If it can be quick to manufacture and cheap, then it will really help the people affected by an amputation.

OPN: How could these technological advances improve patient experience?

ES: To help amputees’ sockets fit their stumps, they currently wear multiple socks and/or a silicone layer, but with the new liner amputees will be able to just simply wear this next to their skin because it fits perfectly. 

This not only gives a more comfortable fit but makes it easier and faster to fit the limb, meaning amputees can quickly put on their prosthetic if they need to get out of bed at night or in the case of a fire.

OPN: Are you currently working on any more research looking at injury prevention for athletes?

ES: I have been working on sport injury prevention during my post doctoral experience in Italy (mainly volleyball), and in UK (mainly rugby). In terms of other projects, I’m involved now in a project entitled ‘Mapping Amputees residuum changes’. This research aims to generate an accurate measure of daily and long-term residual limb volume changes in lower limb amputees, providing data, which can immediately be utilised for patients’ rehabilitation and adaptable prosthetic liners design.

For more details on the study, please visit: