Changes of the soft tissue of the forefoot during loading: a volumetric study

Abstract

Background: Although complaints of the forefoot are frequent, little is known about the changes in the soft tissue of the forefoot that take place during loading. Objective: To study the volume changes of the soft tissue of the forefoot in reaction to loading in normal volunteers and to compare it to the described changes in the heel pad. Method: With computed tomography (CT), the volume distribution of the soft tissue of the right forefoot of 11 healthy volunteers was examined in unloaded and in loaded posture. Results: The decrease of the overall volume of the forefoot (4.8%) in the loaded posture was located on the plantar side. A small increase in volume (1.6%) occurred on the dorsal side of the forefoot at the metatarsal (MT) level. Conclusions: The changes in soft tissue volume distribution in the forefoot by loading resemble observations in the heel region. The increase in volume on the dorsal side is unique for the forefoot and likely reflects a dorsal shift of soft tissue in the intermetatarsal spaces. The decrease in the overall volume was due to compression of plantar venous structures. Both observations may have an important function in shock absorption. In normal volunteers, the volume differences are so prominent that the described procedure may find clinical use in early identification of tissue damage.