A new neural network architecture named CatEquiv has been introduced for Human Activity Recognition (HAR) using inertial sensors. This model encodes various symmetries inherent in the sensor data by capturing the categorical symmetry structure, which enhances its ability to recognize human activities more effectively. The CatEquiv architecture leverages these encoded symmetries to improve the accuracy of activity recognition tasks. Multiple sources confirm the positive effectiveness of CatEquiv in this application domain, highlighting its promising performance improvements. By integrating category-equivariant features, the model addresses challenges in HAR related to sensor data variability. This approach represents a significant advancement in neural network design tailored for inertial sensor-based activity recognition. The consistent claims across recent studies underscore CatEquiv’s potential as a robust solution in this field.