Abstract
This study was aimed to develop a non-invasive technique to analyse motion of the patella during the gait cycle. Ten subjects with no history of patello-femoral pain syndrome or evidence of patella mal-tracking on clinical examination were individually assessed on 160 dynamic walking trials. Retro-reflective markers were attached to the proximal, distal, medial and lateral poles of the patella and the position of the patella relative to the centre of the knee joint was tracked and recorded during their gait cycle using a nine camera (120Hz) ViconTM infra-red motion analysis system.
We found that there was more medial-lateral motion (shift) of the patella than proximal-distal (tilt) motion during the gait cycle. It was noted that the patellar shift motion occurred in the swing phase or the early stance phase of the gait cycle of all subjects with the maximum patellar shift occurring when the knee was flexed between 30–56 degrees in the majority of subjects. Similarly the patellar tilt motion occurred in the swing phase or the early stance phase of the gait cycle with the maximum patellar tilt occurring between 20–36 degrees of knee flexion in the majority of subjects.
These results indicate that normally the maximum amount of patellar shift and tilt occurs in the swing and early stance phases of the gait cycle and that abnormal patellar motion can be detected if excessive shift or tilt occurs outside of these phases. From the findings of the current study, it is proposed that future studies are needed to quantify patellar motion during walking. The future work should be directed to assess patellar motion during swing phase and early stance phase of the gait cycle using more sophisticated techniques like dynamic magnetic resonance imaging to exactly quantify patellar motion.
Correspondence should be addressed to Editorial Secretary Mr ML Costa or Assistant Editorial Secretary Mr B.J. Ollivere at BOA, 35–43 Lincoln’s Inn Fields, London WC2A 3PE, England; Email: mattcosta@hotmail.com or ben@ollivere.co.uk
