1. Unisa Biomechanics Research Lab, Department of Mechanical Engineering, School of Engineering, College of Science Engineering and Technology, University of South Africa , Pretoria 0184, South Africa ; , London SW7 2BX, UK
2. Department of Bioengineering, Imperial College London , Pretoria 0184, South Africa ; , London SW7 2BX, UK
3. Department of Bioengineering, Imperial College London , London SW7 2BX, UK
4. Department of Bioengineering, Imperial College London , London SW7 2AZ, UK