Biomechanical study of foot force pattern in Hallux Valgus (HV) patients

Abstract

Background: Hallux valgus is the angulation of the big toe of more than 15 degrees. Many people during their lives are challenged with this condition. The occurrence is 3 times more in women to men. However one of the causes of the condition is congenital but the other important factor is wearing narrow toe box and high heel shoes. There are some devices measuring the foot kinematic or sole pressure for identifying such condition but as there are lots of variations in foot kinematics and pressure the identification of the disease becomes more challenging. Many previous works are published regarding to foot sole pressure pattern but still early recognition of the condition is needed. Method: To see the existence of force pattern out of gait experiments, Rs-Scan device used to take the kinematic data of the one complete foot contact. 10 trials were conducted of each volunteer with the full right foot contact with the pressure mat. 3 valid trials have been chosen for final analyses. With this method the load/pressure measurement under the 10 anatomical regions of the foot have been recorded and used to recognise people with and without deformity. Furthermore, Motion Capture cameras were used to capture the first and the second metatarsal movements in HV and Non HV volunteers to see whether there is a joint laxity of the metatarsals in HV patients. Results: It was observed that the load pattern in forefoot in people with HV was significantly different compared to non HV volunteers.So independent sample T-Test done and the statistical difference less than 0.05 observed in Toe1,Metatarsal 1,Metatarsal 2, Metatarsal 3, Metatarsal 4 and Metatarsal 5. So just there was no difference load pattern on the Toe 2-5. Hence, the maximum load was on the 2nd and 3rd metatarsal heads in people with HV which is already published by previous authors but the walking speed showed a significant effect on the force variations in both group. The relative movements captured by 7 cameras in Motion Capture laboratory were monitored and it has shown the greater movement of first and second metatarsal heads in patients with HV. Conclusion: The observed force pattern was changing trial to trial in each individual to have a consistent reading they asked to walk 10 times over the pressure mat. After getting this, it was discovered that there is a relationship between walking speed and maximum load applied to the forefoot. Also there was rising load on the 2nd and 3rd metatarsal heads in HV patients. Hence, the 6 regions on the forefoot including Toe1, Meta1, Meta 2, Meta 3, Meta 4, Meta 5 were statistically different while comparing HV and control group. It should be indicated that HV group also had more lateral movement of the first metatarsal head comparing to control group. © 2014 Springer International Publishing Switzerland.