The dataset includes 4244 trials of EMG recordings after ipsilateral TMS under muscle contraction. This data was used for the evaluation of the DiMEP toolbox https://pypi.org/project/dimep/ All subjects provided written, informed consent before participation and following approval by the local ethics committee. Subjects had no contraindications to TMS. TMS was delivered with a MagVenture MagPro-R30 with MagOption and a MCF-B70 figure 8-coil at an orientation of 45° to the midsagittal plane (see figure 1A). First, the motor hotspot of the contralateral, i.e., right, extensor digitorum communis (EDC) was determined by applying 40 stimuli to the left hemisphere. 40% MSO was used as the starting intensity and increased in steps of 5% MSO in case no MEPs could be elicited. Next, at the locations of the three stimuli that resulted in the greatest MEP, i.e., the largest MEP peak-to-peak amplitude, additional three stimuli were applied. The stimulation location that consistently elicited the largest MEPs in the contralateral EDC was then selected as the hotspot. A neuro-navigation system (TMS Navigator, Localite GmbH, Germany) supported coil positioning throughout the measurements. In order to measure ipsilateral MEPs, TMS pulses were applied to the motor hotspot with 5s ± 1.25 s between pulses (at an intensity of 90% MSO). To increase the likelihood of exhibiting ipsilateral MEPs, subjects were requested to isometrically contract their left biceps brachii (BB) to 30% of its maximum voluntary contraction while receiving visual feedback of the BB activity relative to the required target level of contraction on a computer display. The electromyographical response (EMG) to TMS was recorded with a BrainProducts ExG bipolar amplifier from the ipsilateral EDC. All trials were divided into 1s segments, i.e., 500 ms before and after each TMS pulse, and sampled at 1000 Hz.