Critical Force Testing

This is a desktop application to measure climbing specific finger strength metrics such as critical force. With this software, it's possible to capture the force applied to a load-cell and analyse the data.

What is critical force?

There is a research paper of Dave Giles et al. (Lattice Training Ltd.) that describes why critical force can be a useful metric for climbers and how it can be measured. This whole software is based on this paper. The paper can be accessed via this link.

Here you can find a video of Dave MacLeod doing the test at Lattice, including some explanations.

Which hardware is required?

• A load-cell (preferably S-type) and 2 eyebolts to hang it up. The maximum load should be higher than the force you can apply to a 20mm crimp with one arm. As long as you're not Alex Megos, 100kg should be fine.
• A (wooden) finger rung, that is somehow attached to the load-cell. Preferably 20mm with 10mm radius to ensure comparability.
• A load-cell amplifier (NAU7802). I am using this one but this one should work as well. Attention! This software is not compatible with the commonly used HX711 amplifier.
• An MCP2221A USB board to connect the amplifier to a computer via USB.
• A cable to connect the MCP2221A and the NAU7802 (Qwiic/STEMMA QT compatible JST-SH cable).

See also this blog.

Which software is required?

This software contains everything you need, to connect to the load-cell, run a workout, and analyze the data.

Use the software

If you want to use the software, you can download the latest release here:

• Executable for Windows (64bit)
• Application for Macs with Intel chips (allow app start)
• Application for Macs with Apple M chips (allow app start)

Contribute to the source code

If you want to contribute to the source code, fix some bugs, or change the background color to pink, you need Python >=3.9. I've developed the software with version 3.11. You can use the requirements.txt file to install the required packages with pip install -r requirements.txt.

The app is started via python start.py.

You can compile an executable/application for windows/mac via pyinstaller start_win.spec or pyinstaller start_mac.spec.

License

Copyright 2024 Dr.-Ing. Philipp Bulling

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.