---
title: "Step 1 - Load data"
canonical: "https://help.vicon.com/space/ProCalc16/12648547/Step%201%20-%20Load%20data"
format: markdown
---
ProCalc always needs some motion-captured data to work with. The data is loaded from a C3D file, which may contain one or more of the following:

- 3D trajectories (XYZ positions of markers in space and time)
- Modeled data (joint angles, moments, forces, powers, and so on), for example, from the Plug-in Gait model
- Standard Vicon events (left/right/general foot strike/foot off/general)
- Analog data (for example, EMG or force plates)

When you start ProCalc, the main ProCalc interface is displayed:

![Main ProCalc interface](media://77e0fc2c-1583-416f-9a87-31199b60ef06)

The main window consists of four parts:

- Top left lists the variables or trials that you’re currently working with.
- Bottom left contains buttons, menus and other controls that let you modify the variables.
- Top right contains the 3D workspace that shows you what you’re working with.
- Bottom right contains a textual log output window.

> Macro (scroll-pagebreak)

**To load data for this tutorial:**

<span style="color: #172B4D">Before you begin, ensure you have downloaded the</span><span style="color: #172B4D"> </span><span style="color: #172B4D">ProCalc Tutorials data as described in </span>[<span style="color: #172B4D">About the data for this tutorial</span>](https://vicon-help.atlassian.net/wiki/spaces/ProCalc16/pages/12649990/Getting+started+with+Vicon+ProCalc#AboutData)<span style="color: #172B4D">.</span>

1. At the top left, click the **Data Management** tab.
2. Navigate to the *Getting Started* session folder
3. Double-click **Walking01** to open the trial in ProCalc.  
The trial is displayed in the 3D workspace as a stick figure, similar to the display in Vicon Nexus.