By Angela Kedgley, Musculoskeletal Mechanics Group at Imperial College London.

Like most academic labs, the Musculoskeletal Mechanics Group at Imperial College London writes a lot of custom code. The Imperial College Lower Limb Model (ICLLM) is the product of some of this. It is a C- and Matlab-based musculoskeletal modelling software package that is currently being used and further developed as part of the Medical Engineering Solutions in Osteoarthritis Centre of Excellence, funded by the Wellcome Trust and the EPSRC. It allows the prediction of subject-specific muscle and joint forces at the hip, knee, and ankle by employing motion data obtained through gait analysis techniques. These outputs may be used to assess disease progression, or evaluate both surgical and non-surgical treatment strategies.

The transient nature of students and staff in academia has meant that the development of the ICLLM has been driven by several different students and researchers. Most of the group are engineers and have not been formally trained in best practices for ensuring the various components of the ICLLM are sustainable. There has been no clear strategy for how to contain the code, or strategies for ensuring easy further development. Documentation was limited, and coding practices were left to the individual developers.

As a huge amount of time and money has gone into generating this code, we knew it was time to develop a long-term strategy for sustainability. We therefore submitted an application to the Software Sustainability Institute via the open call for projects.

The Institute conducted a technical evaluation of the ICLLM and a full assessment of our development processes and documentation. The Institute's team were invaluable and proposed a new workflow that involved adhering to coding standards, introducing a revision control system, and developing a code testing framework. In many ways the suggestions were simple, but they were not ideas that as engineers we’d been formally exposed to in the past. The next stage of the project is to implement an online Subversion (SVN) code repository and revision control system with some assistance and guidance by the Institute.

Since the Software Sustainability Institute evaluation we’ve also beefed up our documentation policies, actively encouraging our team members to take the time to ensure that any code written will be useable even if that individual team member moves on. It may take a little extra time in the short-term, but the Osteoartiritis Centre of Excellence aims to tackle big problems, and putting in that extra effort to ensure our code continues to be useful means the investment of our funders, the Wellcome Trust and EPSRC, is money well spent.