Demands on the Knee During Kneeling and Squatting Activities Common to Low-seam Mining

In 2009, the operating height of approximately one fourth of underground coal mines in the U.S. restricted mine workers to kneeling, crawling, and/or stooping posture to perform work. In response to a large number of knee injuries in miners, NIOSH investigated three different biomechanical parameters (muscle activity of the knee flexors and extensors, pressure at the knee, and the net forces and moments at the knee) as subjects assumed postures common to low-seam mining, both with and without kneepads.