INTRODUCTION:Missing-heel shoes are propagated for the prevention of problems of the locomotor system by strengthening of muscles and are thought for rehabilitation purposes e.g. of Achilles-tendon problems and chronic lumbago.The objective of this study was to compare gait patterns of nonsymptomatic subjects walking with missing-heel shoes with patterns obtained with a normal shoe-sole geometry by means of kinematic and kinetic analyses.METHODS:Three-dimensional motion analysis was performed using a VICON system for data capture; ground reaction forces (GRF) were simultaneously recorded with two KISTLER force plates. Video cameras documented the trials in the sagittal and frontal plane. Seven healthy young subjects (25.4+/-4.1 years, 182.3+/-4.2cm, 72.4+/-2.8 kg) were recorded standing upright and walking at a self-selected free gait velocity. The test subjects underwent an instructional session before data collection in order to ensure adequate 'missing-heel-shoe-gait-technique'. Results were compared between normal shoe and missing-heel shoe.RESULTS:Standing: With missing-heel shoes, ankle- and knee joints were significantly more flexed. The hip joint tended to extend more, but the results were not consistent across subjects. The overall trunk position did not alter.Walking: Time-distance parametersWalking speed was reduced significantly with the missing-heel shoe as a consequence of a shorter stride length combined with an increased cadence. No other time-distance-parameters did discriminate.Kinematic analysis of sagittal plane motions: The walking pattern differed drastically at the ankle joint, resulting in a sudden rocking motion at the heel followed by a significantly prolonged and augmented dorsiflexion. No significant differences were found at the level of the knee and hip joints.Kinetic analysis: Significant differences were found in GRF parameters until mid-stance. Additionally, the shape of the GRF curves were markedly different between the two conditions.DISCUSSION:The rocking movement around the ankle joint involves sudden changes in movement speed and may therefore produce high stresses on the Achilles tendon. Greater knee flexion angle may result in higher stresses in the knee-joint due to increased and prolonged muscle activity of the knee-extensors.CONCLUSION:The walking pattern with missing-heel shoes differs drastically from the pattern with normal sole geometry in the sagittal plane during the first half of the gait cycle. Depending on the individual situation, these sudden changes in speed may be either a) of considerable therapeutical value or b) an unnecessary load for passive and/or active structures of the lower limbs and the spine.Prospective studies will be necessary to document the long-term effects of the use of a missing-heel shoe.