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NDORMS DPhil & MSc by Research

project outline

Optical motion capture systems are the most widely used method of assessing human motion. The movement of markers attached to the skin are used to represent the motion of the underlying bony anatomy. However, skin‐markers slide relative to the underlying bone, a phenomenon known as Soft Tissue Artefact (STA). Studies have quantified STA for different limbs during a variety of activities like walking and running [1, 2]. STA tends to be greatest for the thigh (femur), with STA values as high as 50mm [3].

We are developing a novel method which combines ultrasound‐imaging with motion analysis to more accurately measure human movement in 3 dimensions called CAT & MAUS (Computer Aided Tracking and Motion Analysis with Ultrasound) [4]. This system reduces STA by imaging the underlying bone during motion. In this project you will refine this system to assess the motion of the knee cap (patella) relative to the femur during knee flexion. The method will be refined using human joints in vitro before being applied to subjects in the Oxford Gait Laboratory. Ultimately, the correlation between pain after a knee replacement and the motion of the patella will be investigated.

Research Group

This project will take place at the Oxford Orthopaedic Engineering Centre which is part of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences based at the Botnar Research Centre. We are an interdisciplinary team consisting of orthopaedic surgeons and bioengineers. We believe engineering is the basic science of orthopaedics and employ motion analysis, musculoskeletal modelling, 3D imaging, segmentation and finite element analysis (FEA) to carry out research on joint mechanics. We currently have seven students, five of whom are doing a DPhil and two doing an MSc.


Students will receive specialist training on the use of the CAT & MAUS system for the analysis of joint mechanics. This will include training in the use of the Vicon motion analysis system at the Oxford Gait Lab and on techniques for the analysis of ultrasound images. A core curriculum of 20 lectures will be taken in the first term of year 1 to provide a foundation in musculoskeletal sciences and data analysis. Students will attend weekly departmental meetings and will be expected to attend seminars within the department. Subject‐specific training will be received through weekly supervision meetings. Students will also attend external scientific conferences where they will be expected to present their research.


  1. Cappozzo, A., et al., Position and orientation in space of bones during movement: experimental artefacts. Clinical Biomechanics, 1996. 11(2): p. 90‐100. 
  2. Reinschmidt, C., et al., Effect of skin movement on the analysis of skeletal knee joint motion during running. Journal of Biomechanics, 1997. 30(7): p. 729‐732. 
  3. Akbarshahi, M., et al., Non‐invasive assessment of soft‐tissue artifact and its effect on knee joint kinematics during functional activity. Journal of Biomechanics, 2010. 43(7): p. 1292‐1301. 
  4. Jia, R., et al., A computer‐aided tracking and motion analysis with ultrasound (CAT & MAUS) system for the description of hip joint kinematics. International Journal of Computer Assisted Radiology and Surgery, 2016: p. 1‐13.

Further information

Enquiries should be directed to Stephen Mellon,

Project reference number #NDORMS-2017/13


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