EVALUATION OF 3D LOWER LIMB KINEMATICS AND KINETICS WITH AND WITHOUT PLANTAR ORTHOPAEDIC PROCESSING Mathieu Tremblay, Nicola Hagemeister, Michel Pelletier, Gerald Parent, Jacques De Guise Laboratoire de recherche en imagerie et orthopédie (LIO), Centre de recherche du CHUM, Hôpital Notre-Dame, Montréal , Québec , Canada
[email protected] INTRODUCTION Although plantar orthoses are regularly prescribed to correct lower limb kinematics and kinetics, only few studies evaluated in a quantitative and non-invasive way the effect of plantar orthoses on knee kinematics. Our research group developed a non-invasive harness allowing threedimensional (3D) assessment of knee kinematics while limiting errors caused by soft tissue movements with respect to underlying bones (Sati, M. et al., 1996a, 1996b and Ganjikia, S. et al., 2000). The purpose of this study was to evaluate quantitatively the immediate effect on kinematics and kinetics following orthotic treatment of rear foot valgus.
the desired correction of orthoses as well as work presented in the literature. For example, a study (Lafortune, M. et al., 1994) using cortical pins showed reduction of tibial internal rotation. Nevertheless, more subjects must be evaluated, in order to perform quantitative and statistical analysis of results. Altogether, 30 patients will be assessed during the study. Neutral Bioform BiOpTech
METHODS For this study, 11 female and 5 male subjects aged between 16 and 54 years (m = 27.3; S = 9.6) were selected. All presented a rear-foot flexible valgus greater than 5°. Three subjects was evaluated for both left and right knees. 19 and 15 lower limbs were evaluated for the kinematics and kinetics assessments, respectively. The orthoses types used were BiOptech and Bioform (Bi-Op, Joliette, Canada). The BiOptech is a semi-rigid orthosis with high control and the Bioform is flexible and exerts a lighter control. The subjects were wearing standardized sandals and were asked to walk on an instrumented treadmill (Adal 3D, Médical Dévelopement, France) at comfortable speed without orthosis, with Bioform and with BiOptech. Order of testing was selected randomly before the experiment. Real time recording of the bone’s space position was performed via infra-red emitting diodes which were attached noninvasively on the harness and a system of three cameras (Optotrak, Northern Digital, Canada). The harness allows measurement of knee movements in the sagittal, frontal and transverse plane with an average precision of 0.4° for the abduction/adduction and 2.3° for tibial rotation movements (Sati, M., et al. 1996) RESULTS AND DISCUSSION Results showed that, depending on the subject, immediate effect of foot orthotic treatment on 3D lower limb kinematics and kinetics could vary. For the kinematic : In 12 of 19 cases, increased external tibial rotation of the knee was observed when subjects walked with the BiOpTech orthoses compared to the walk without orthosis. In 10 of 19 cases, Bioform had no effect on tibial rotation and abduction. The majority of the effects on kinematics were weak. Figure 1 shows an example of a patient for whom an increase of tibial external was observed with the wear of the BiOptech orthosis. Our result propose that Bioform orthoses affect the kinetic in antero-posterior force in 8 of 15 cases and BiOptech orthoses affect the medio-lateral force in 10 of 15 cases. Most observed effects are in accordance with
Figure 1: 3D kinematic curves typical patient. Black lines represent knee joint angles during gait without orthosis. Black dotted lines give the acquisition error (mean standard deviation). Red ones represent gait with BiOptech orthosis. Blue one represent gait with Bioform orthosis. Only stance phase of gait was analysed. SUMMARY This study aimed at assessing the effect of plantar orthopaedic processing on 3D lower limb kinematics and kinetics. Preliminary results showed that the method could be useful to quantify the effects of the orthosis on kinematics and kinetics and it could make it possible to make better a functional assessment of the patients. More patients are required to perform quantitative and statistical analysis. REFERENCES Sati, M. et al. (1996).. Knee. 3 ; 121-38. Sati, M. et al. (1996). Knee. 3 ; 179-90. Ganjikia, S. et al. (2000) . Knee. 7 ; 221-31. Lafortune, M. et al. (1994.). J Orthop Res. 12 ; 412-20.
