The Effect of Running Shoes on Lower Extremity Joint Torques
Received 30 June 2009; accepted 22 September 2009.
Objective
To determine the effect of modern-day running shoes on lower extremity joint torques during running.
Design
Two-condition experimental comparison.
Setting
A 3-dimensional motion analysis laboratory.
Participants
A total of 68 healthy young adult runners (37 women) who typically run in running shoes.
Methods
All subjects ran barefoot and in the same type of stability running footwear at a controlled running speed. Three-dimensional motion capture data were collected in synchrony with ground reaction force data from an instrumented treadmill for each of the 2 conditions.
Main Outcome Measurements
Peak 3-dimensional external joint torques at the hip, knee, and ankle as calculated through a full inverse dynamic model.
Results
Increased joint torques at the hip, knee, and ankle were observed 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.
Conclusions
The findings at the knee suggest relatively greater pressures at anatomical sites that are typically more prone to knee osteoarthritis, the medial and patellofemoral compartments. It is important to note the limitations of these findings and of current 3-dimensional gait analysis in general, that only resultant joint torques were assessed. It is unknown to what extent actual joint contact forces could be affected by compliance that a shoe might provide, a potentially valuable design characteristic that may offset the observed increases in joint torques.
aJKM Technologies LLC, 525 Rookwood Place, Charlottesville, VA 22903†
bDepartment of Integrative Physiology, University of Colorado, Boulder, CO‡
cDepartment of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, VA§
dDepartment of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, VA¶
eDepartment of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, VA; and Department of Biomedical Sciences, University of Sassari, Italy∥
fDepartment of Physical Medicine and Rehabilitation, University of Virginia, Charlottesville, VA#
Address correspondence to: D.C.K.
Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org
† Disclosure: 1B, developed patented footwear design used by JKM Technologies, LLC and the OESH brand; 7B, Brooks Sports Inc.
ABSTRACT