Kinematic indicators of physical fatigue during walking: A systematic review of assessment parameters and protocols

Physical fatigue is a critical concern for the health and safety of construction workers. Traditional fatigue assessment methods, such as surveys, are time-intensive and lack real-time applicability during activities like walking. This review identifies key kinematic parameters relevant to real-time fatigue assessment and examines fatigue-inducing activities that alter these parameters. A search of key databases (2000-2024) identified 19 relevant studies from 352 articles. Studies varied in fatigue induction methods and measured parameters. Three types of fatigue-localized muscle, multi-joint, and whole-body-were induced. Gait speed, stride length, step width, heel contact velocity, and trunk acceleration were commonly assessed and significantly affected by fatigue. Fatigue in key muscles, including the quadriceps and ankle plantar flexors, had the greatest impact on walking kinematics. This review contributes to the existing literature by systematically identifying and organizing kinematic parameters that are practical for real-time, non-invasive fatigue monitoring. It also highlights the challenge of comparing studies that used different fatigue protocols and explains how these findings can support monitoring in real-world environments like construction, where walking is both common and physically demanding. Together, these contributions address an important research gap and provide a foundation for developing injury prevention strategies using wearable technologies.