Running Shoes May Cause Damage to Knees, Hips and Ankles

New York, 4 January 2010 – Knee osteoarthritis (OA) accounts for more disability in the elderly than any other disease. Running, although it has proven cardiovascular and other health benefits, can increase stresses on the joints of the leg. In a study published in the December 2009 issue of PM&R: The journal of injury, function and rehabilitation, researchers compared the effects on knee, hip and ankle joint motions of running barefoot versus running in modern running shoes. They concluded that running shoes exerted more stress on these joints compared to running barefoot or walking in high-heeled shoes.

Sixty-eight healthy young adult runners (37 women), who run in typical, currently available running shoes, were selected from the general population. None had any history of musculoskeletal injury and each ran at least 15 miles per week. A running shoe, selected for its neutral classification and design characteristics typical of most running footwear, was provided to all runners. Using a treadmill and a motion analysis system, each subject was observed running barefoot and with shoes. Data were collected at each runner’s comfortable running pace after a warm-up period.

The researchers observed increased joint torques at the hip, knee and ankle with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.

These findings confirm that while the typical construction of modern-day running shoes provides good support and protection of the foot itself, one negative effect is the increased stress on each of the 3 lower extremity joints. These increases are likely caused in large part by an elevated heel and increased material under the medial arch, both characteristic of today’s running shoes.

Writing in the article, lead author D. Casey Kerrigan, MD, JKM Technologies LLC, Charlottesville, VA, and co-investigators state, “Remarkably, the effect of running shoes on knee joint torques during running (36%-38% increase) that the authors observed here is even greater than the effect that was reported earlier of high-heeled shoes during walking (20%-26% increase). Considering that lower extremity joint loading is of a significantly greater magnitude during running than is experienced during walking, the current findings indeed represent substantial biomechanical changes.” Dr. Kerrigan concludes, “Reducing joint torques with footwear completely to that of barefoot running, while providing meaningful footwear functions, especially compliance, should be the goal of new footwear designs.”

The article is “The Effect of Running Shoes on Lower Extremity Joint Torques” by D. Casey Kerrigan, MD, Jason R. Franz, MS, Geoffrey S. Keenan, MD, Jay Dicharry, MPT, Ugo Della Croce, PhD, and Robert P. Wilder, MD. It appears in PM&R: The journal of injury, function and rehabilitation, Volume 1, Issue 12 (December 2009), published by Elsevier. The article has been made freely available and may be accessed at: http://www.pmrjournal.org/article/S1934-1482(09)01367-7/fulltext .

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Notes For Editors
The article has been made freely available and may be accessed at: http://www.pmrjournal.org/article/S1934-1482(09)01367-7/fulltext.
Journalists wishing to interview the authors should contact Joanne Constantine at 847 737-6014 or jconstantine@aapmr.org.

Authors
D. Casey Kerrigan, MD, JKM Technologies LLC, Charlottesville, VA 22903
Jason R. Franz, MS, Department of Integrative Physiology, University of Colorado, Boulder, CO
Geoffrey S. Keenan, MD, Department of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, VA
Jay Dicharry, MPT, Department of Physical Medicine and, Rehabilitation, University of Virginia, Charlottesville, VA
Ugo Della Croce, PhD, Department of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, VA; and Department of Biomedical Sciences,
University of Sassari, Italy
Robert P. Wilder, MD Department of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, VA

About PM&R: The Journal Of Injury, Function And Rehabilitation 
PM&R is the official scientific journal of the American Academy of Physical Medicine and Rehabilitation (AAPM&R). It is a monthly, peer- reviewed, scholarly publication under the leadership of Editor-in-Chief Stuart M. Weinstein, MD, that advances education and impacts the specialty of physical medicine and rehabilitation through the timely delivery of clinically relevant and evidence-based research and review information. Various topics covered include acute and chronic musculoskeletal disorders and pain, neurologic conditions involving the central and peripheral nervous systems, rehabilitation of impairments associated with disabilities in adults and children, and neurophysiology and electrodiagnosis. PM&R emphasizes principles of injury, function and rehabilitation, and is designed to be relevant to practitioners and researchers in a variety of medical and surgical specialties and rehabilitation disciplines. Submission of manuscripts is encouraged from physiatrists, physicians and researchers in related disciplines, and other multidisciplinary rehabilitation professionals.

The content of PM&R includes articles that are contemporary and important to both research and clinical practice. The various sections of the journal highlight original research including clinical trials and outcomes studies, clinically relevant translational science, comprehensive and focused review articles, case presentations, point/counterpoint discussions and commentary, literature reviews (including structured abstracts and book reviews), ethical legal topics, practice management updates, topical study guides, editorial and opinion pieces, images, clinical pearls and emerging issues.

About The American Academy Of Physical Medicine And Rehabilitation (AAPM&R)
Founded in 1938 to treat musculoskeletal and neurological problems, AAPM&R is the national medical specialty society of more than 7500 physical medicine and rehabilitation (PM&R) physicians, also called physiatrists. PM&R physicians care for patients with acute and chronic pain, catastrophic injuries, musculoskeletal disorders, back pain, and work- or sports-related injuries. They also coordinate the long term rehabilitation process for patients with spinal cord injuries, cancer, stroke or other neurological disorders, brain injuries, amputations and multiple sclerosis.

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Media Contact:
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