Exercise & Training

Single-Camera Knee Adduction Moment Estimation for Individuals With Knee Osteoarthritis via a Novel Spatio-Temporal Graph Transformer Network.

TL;DR

A novel Spatio-Temporal Graph Transformer Network using a single-camera setup achieved KAM root mean square error of 0.48% BW·BH and peak KAM mean absolute error of 0.43% BW·BH, both within clinically meaningful error thresholds, suggesting feasibility for real-world gait assessment in individuals with knee osteoarthritis.

Key Findings

The proposed STGTN model achieved KAM estimation accuracy within clinically meaningful error thresholds using a single-camera setup.

  • KAM root mean square error was 0.48% BW·BH
  • Peak KAM mean absolute error was 0.43% BW·BH
  • Both metrics fell within the clinically meaningful error threshold range of 0.5–2.1% BW·BH
  • The model was tested on 14 individuals with medial compartment knee OA

The STGTN model demonstrated sensitivity to gait modifications by identifying significant reductions in peak KAM across multiple conditions.

  • Significant reductions in peak KAM were identified during slow walking, toe-in gait, wide step width, and increased trunk sway conditions
  • All identified reductions were statistically significant (p < 0.05)
  • Gait modifications tested included variations in walking speed, foot progression angle, step width, trunk sway, and dual-task walking

Fourteen individuals with medial compartment knee osteoarthritis performed multiple gait modifications as the study population.

  • Participants had medial compartment knee OA
  • Five categories of gait modifications were performed: walking speed, foot progression angle, step width, trunk sway, and dual-task walking
  • This represents a diverse set of gait conditions for model validation

Traditional KAM measurement systems are costly and restricted to laboratories, motivating the development of a single-camera alternative.

  • Traditional motion capture and force plate systems are costly and restricted to laboratories
  • Multi-wearable sensor and multi-camera setups have been explored but remain complex
  • Prior multi-sensor and multi-camera approaches lack validation across diverse gait modifications in individuals with knee OA
  • A single-camera setup was proposed as a feasible approach for real-world gait assessment

The single-camera-based KAM estimation approach has potential applications in clinical and rehabilitation settings for monitoring knee joint loading and exploring feedback-driven KAM reduction.

  • The approach is described as potentially applicable for monitoring knee joint loading
  • The authors highlight potential for feedback-driven KAM reduction applications
  • The system targets real-world gait assessment outside of traditional laboratory settings
  • The model's sensitivity to clinically relevant gait modifications supports its translational potential

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Citation

Wang H, Liang K, Zhu K, Xu C, Mansour O, Lu Q, et al.. (2026). Single-Camera Knee Adduction Moment Estimation for Individuals With Knee Osteoarthritis via a Novel Spatio-Temporal Graph Transformer Network.. IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society. https://doi.org/10.1109/TNSRE.2026.3672626