This article is part of our Injury Analysis series.Jerick McKinnon and Matt Breida
The 49ers starting running back Jerick McKinnon made an early exit from practice on Sunday with what appeared to be a knee injury. McKinnon was seen grabbing the back of his right knee and would later undergo a MRI on the area. The medical imaging revealed a low-grade calf strain that will keep him sidelined for at least a week.
The results of the MRI may surprise people that don't normally associate the calf muscle complex with the knee. However, the calf is a two-joint muscle, meaning it's active in two different areas. Most people know the calf attaches to the heel via the Achilles' tendon, but they tend to overlook that it originates above the knee joint.
You've reached the end of our free article preview.