Summary

Main question:
How does the MBT sandal influence the muscle activity, the plantar pressure and kinematics and kinetics of the lower limb during walking compared to normal footwear in healthy subjects and what conclusions can be drawn concerning the benefits of the MBT sandals for patients with knee osteoarthritis?


Objective:
Gain knowledge about the muscle activity, plantar pressure and kinematics and kinetics of the lower limb of healthy subjects when walking, comparing the MBT sandal and normal footwear and draw conclusions about the benefits of the MBT sandal on osteoarthritis of the knee.

Method:
An experiment was carried out in the gait laboratory at the Fontys University of Applied Science. 12 healthy subjects were selected for this study, 6 males and 6 females. Their mean age was 25, 3 years (SD: 2, 6), height 173, 3 cm (SD: 5, 6), weight 69, 6 kg (SD: 7, 3) and BMI 23 (SD: 2). All subjects signed an informed consent for their participation in the study. The participants and normal shoes were selected by applying inclusion and exclusion criteria.
The measurement tools employed during the experiment were the Sybar system, the Pedar® insole system and the treadmill Technogym.
The EMG, knee angle and ground reaction force were assessed with the help of the Sybar system. The EMG of each participant was established by means of the Biometrics, 8 channel system and skin electrodes put on the muscles to be tested; the knee angle was evaluated using video cameras (Sony, 25Hz), reflective markers and a software for determination of knee angles; the GRF was quantified by the use of a force plate (AMTI, 500Hz)
The plantar pressure was measured using the Pedar® insole system and a treadmill (Technogym).
Data analysis took place using SPSS (Version 15). The mean and standard deviation were calculated by means of the Microsoft office Excel (version 11, 2003). The Wilcoxon signed rank test was performed in order to assess statistical significance. The significance level was set at p< 0, 05.


Results:
There were significant findings in the plantar pressure measurement and the ground reaction force, comparing the normal shoes with the MBT condition
The first maximal force in the vertical direction (loading response) was significantly lower for the MBT sandal (p< 0.05).The time it took to reach the first maximal force peak (from initial contact) in antero-posterior direction, was significantly (p< 0.05) faster in the MBT condition.
The results of the plantar pressure measurements demonstrated a significant (p< 0, 05) decrease for the MBT sandal in the PTI, PP and MF at the heel and the PP and MF at the forefoot.
The last finding illustrated a significant (p=0, 003) increase for the MBT sandal in PTI and MF at the mid foot.


Conclusion:
Based on this experimental study, the authors conclude that the MBT sandal alters gait kinetics and plantar pressure when compared to normal shoes. However, it cannot be concluded what influence these changes have on osteoarthritic knees.