Effects of transcranial magnetic stimulation of the primary motor cortex on the grip and net forces in the tripod grasp

Transcranial magnetic stimulation (TMS) is a tool of choice to study the functionality of the corticospinal pathway in the intact human. In this study, we used TMS to stimulate the hand area of the primary motor cortex (Ml) and measured TMS-evoked forces in a multi-fingered grasp. This short report aims at presenting the experimental setup and some preliminary results. The analysis of the data from one subject suggests that TMS affects differently the grip force (which measures the overall force involved in the grasp) and the net force (which measures the net effect of all contact forces exerted on the object).