Cause of the left–right gate asymmetry

Determine the cause of the observed left–right asymmetry in the learned foot-orientation gate values, which cannot be explained by the measured bias magnitudes.

Background

The reliability-gated model assigns substantially different mean gate values to the left and right foot-orientation channels on clean real data: approximately 0.41 for the left foot and 0.15 for the right foot. The authors report that the corresponding median bias magnitudes are nearly identical, 34.3° and 35.0°, respectively.

Because the asymmetry is not accounted for by the measured orientation-bias magnitude, its source remains unresolved. Identifying the cause could clarify whether the gates are responding to other channel-specific fault characteristics, device-side differences, mounting conditions, data artifacts, or distinct motion and signal statistics.

References

The left/right asymmetry ($0.41{\pm}0.10$ vs. $0.15{\pm}0.04$) is unexplained by bias magnitude (median $|B|$ $34.3\circ$ vs. $35.0\circ$): gate value is channel-specific fault structure, not a calibrated scalar.

— Reliability-Gated Fusion of Consumer Head and Foot IMUs for Lower-Body 3D Pose  (2609.35764 - Guo et al., 28 Sep 2026) in Section 5.3, “What the gates learn” (Section \ref{sec:interp})