Investigation of the relationship between plantar pressure and calf muscle tone. Development and testing of the new test bench

Plantar pressure is the most important biomechanical parameter for evaluating and modeling postoperative treatment conditions for patients with deformity of the first ray of the foot. Modern foot surgery involves early activation of the patient after surgery. The universality and reliability of this approach after surgical correction of valgus deformity of the first toe is questionable. In this regard, studies are being conducted to determine the quantitative parameters of plantar pressure under normal conditions and with the use of postoperative footwear used to reduce it in the forefoot. The relationship between calf muscle tone and plantar pressure in the forefoot has been established. There have been no studies determining the influence of calf muscle tone on the effectiveness of unloading the forefoot using postoperative footwear. The plantar pressure has been studied experimentally, including the influence of the calf muscle tone. An experimental stand was developed and tested: it was used to study the distribution of pressure under the foot in 26 healthy individuals in the standing position on a platform and in postoperative shoes. Quantitative assessment of the tone of the calf muscle in the same subjects was carried out. The plantar pressure in subjects wearing postoperative shoes and the amplitude of dorsal flexion of the ankle joint with the knee joint straightened and flexed at 90 degrees were compared. The mean load reduction in postoperative shoes was 57%, median 60%. Measurement of calf muscle tone (extensibility) can be used to predict whether forefoot loading will be reduced with the use of special shoes. The dorsiflexion angle of the foot should be used as a criterion: if it is greater than 10 degrees, there is a high probability that forefoot loading will be reduced. For dorsiflexion measured at the straightened knee joint, the probability of predicting the effectiveness of postoperative footwear is 79%. A similar probability when using the amplitude of dorsiflexion of the foot measured with the knee joint flexed at 90 degrees as a prediction criterion was 66%.