Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Stress fractures can be considered an overuse injury of a bone. The bones in
the body are constantly changing, responding to the work load that is placed
upon them, and there is a constant turnover of cells as bone acts to repair
itself. The more load placed on the bone, the more likely that calcium will be
placed at that site. The less use a bone receives, the less calcium can be
found within it. If the stress of repetitive loads overwhelm the ability of the
bone to repair itself, small cracks can begin to occur within the bone
This is especially evident in the bones of the foot, leg,
and pelvis. These bones need to absorb the forces created from walking, running, and jumping. Up
to 12 times the weight of the body may be generated with each step; and the
bones, joints, muscles, and ligaments need to cushion the body against that
Bone is normally in homeostasis (homeo= same + stasis=standing still),
meaning that the natural turnover of bone cells is in balance between osteoclast
activity (bone breakdown) and osteoblast activity (bone creation). When bone is
under stress, it undergoes microscopic damage. Osteoclast cells are stimulated
to absorb bone, and the injured site is weakened. If a long period of time
elapses prior to the next injury, osteoblast cells produce more bone cells to protect the damaged
area. If there is not enough time for the osteoblasts to produce more bone cells
in the injured area; the micro
fractures can join together to form a large enough area to cause a stress
Symptoms of a stress fracture may include pain and swelling,
weight bearing on the injured bone. Often plain
X-rays may appear normal.
If stress on the area of the compromised bone continues, and the microscopic damage
increases in the area; the bone's integrity can be
completely disrupted and cause a fracture that can be recognized on X-rays.
Stress fractures generally often occur in the following locations:
Stress Fractures: Some Take Longer to Heal Than Others
Medical Author: Benjamin C. Wedro, MD, FAAEM Medical Editor: William C. Shiel Jr., MD, FACP, FACR
It takes a lot of effort to support 7 feet 6 inches and
the two tons of force generated when NBA basketball star Yao Ming walks or
jumps. The cushioning that absorbs the shock of his weight rests on two feet and
their joints, ligaments, and muscles. The force of that weight during runningcan
multiply a person's weight by more than12 times. Unfortunately for the Houston
Rocket basketball player, his bones couldn't withstand the constant pounding and
he developed a stress fractureof the navicular bone of his foot.
The navicular bone helps support the arch of the foot and
is a bridge between the bones of the ankle and those of the toes. The bony arch
is also supported by the plantar fascia, the thick band of tissue that connects
the heel to the front of the foot. The solid bones and the pliable ligaments
flex the foot to disperse the forces generated with walking, running, and
jumping. But if the force placed on the bone is greater than its ability to
withstand it, small micro fractures can occur in the bones that can develop into
a stress fracture.