Dynamic in Vivo Subtalar Joint Kinematics Measured Using a Skin Marker–Based Protocol

Abstract

Background The subtalar joint allows complex motion of the foot relative to the leg, the analysis of which has presented a major challenge for researchers. The considerable interpatient variation in structure and function of the subtalar joint highlights the importance of developing a protocol to assess the kinematics in individuals rather than developing an overarching description of function. The use of skin-mounted markers is, therefore, preferable, allowing the noninvasive collection of data. We sought to assess the face validity of a skin-mounted marker–based protocol to measure the in vivo kinematics of the subtalar joint. Methods Thirty participants were recruited using minimal exclusion criteria. A previously tested skin-mounted marker placement protocol was used in conjunction with two CODA MPX 30 sensors to capture data during walking. The data produced were compared with those from previous studies that used bone-mounted markers. Results The results in all three planes represented feasible outcomes compared with those of previous studies, the data falling within the ranges published. Patterns of movement demonstrated are similar to, although not the same as, those shown by previous investigations. Conclusions This study did not produce patterns of movement that exactly matched those of previous investigations. The results were, however, within the ranges previously published, and the patterns of movement shown were feasible. The results suggest the face validity of the method as a means of assessing the in vivo kinematics of the subtalar joint during the stance phase of gait.