Researchers in the US who compared the effects on hip, knee and ankle joints of running barefoot versus running in modern running shoes, concluded that running in shoes exerted more stress on these joints compared to running barefoot or even walking in high-heeled shoes.

The study was the work of lead author Dr D Casey Kerrigan, of JKM Technologies LLC, in Charlottesville, Virginia and colleagues from the University of Colorado and the University of Virginia, and was published in the December 2009 issue of PM&R: The journal of injury, function and rehabilitation.

Knee osteoarthritis (OA) accounts for more disability in the elderly than any other disease, and although running has been shown to benefit health in many ways, including cardiovascular health, it can stress the joints in the leg, such as the hip, knee, and ankle.

For the study, Kerrigan and colleagues recruited from the general population, 68 healthy young adults (37 women, 31 men) with no history of musculoskeletal injury and who regularly ran at least 15 miles a week in running shoes that are typically available in the shops.

They gave each of the participants a pair of running shoes that was typical of most running footwear, but bore no particular design characteristics and appeared neutral. They then observed the participants running with these shoes on, and also barefoot, on a treadmill, with a motion analysis system. The data was collected after a warm up period and while the runners were running at a pace that was comfortable to them individually.

They observed that, compared with barefoot running, running with running shoes resulted in:

  • Increased joint torques at the hip, knee and ankle.
  • Disproportionately large increases in the hip internal rotation torque and in the knee flexion and knee varus torques.
  • On average these torque increases were: 54 per cent in hip internal rotational, 36 per cent in knee flexion, and 38 per cent in knee varus.

(Joint torque is a measure of the amount of twisting about an axis that goes on at that joint. There are several kinds of torque measure, depending on the joint, which axis is the centre of rotation, and the types of movement through which the attached limbs travel.)

The researchers concluded that while typical running shoes support and protect feet quite well, they increase stress on the hips, knees and ankles, and this is likely to be caused by an elevated heel and extra material under the medial arch.

They also remarked that the 36 to 38 per cent ncreased torque on knee joints observed in the running shoes is even greater than that observed in earlier research on walking in high heeled shoes, which showed a 20 to 26 per increased torque on knee joints.

“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,” said Kerrigan in a press statement, adding that the goal of new footwear design should be to reduce joint torque so it is on a par with barefoot running, while not compromising other functions.

“The Effect of Running Shoes on Lower Extremity Joint Torques.”
D. Casey Kerrigan, Jason R. Franz, Geoffrey S. Keenan, Jay Dicharry, Ugo Della Croce, Robert P. Wilder
PM&R, Volume 1, Issue 12 (December 2009).
DOI:10.1016/j.pmrj.2009.09.011

Source: Elsevier Health Sciences.

Written by: Catharine Paddock, PhD