Can footwear affect achilles tendon loading?
OBJECTIVE
To investigate the effects of footwear on Achilles tendon tension by directly measuring Achilles tendon tension and dorsiflexion range of motion.


METHODS
A total of 48 matched pair tests were performed comparing the effects of shoe type (high-top vs low-top) for each shoelace configuration (tied vs untied). These were performed using the Achilles tendons of 4 human cadaver lower extremities that were instrumented with a customized load cell designed to measure tension. The lower extremity was inverted in a custom testing apparatus designed to inertially invoke dorsiflexion of the foot, putting the Achilles tendon in tension.


METHODS
Research laboratory.


METHODS
Left and right lower extremities of 2 human cadavers.


METHODS
None. Independent variables were shoe type and shoelace configuration.


METHODS
Achilles tendon tension and dorsiflexion range of motion.


RESULTS
High-top shoes significantly reduced peak Achilles tendon tension by an average of 9.9% when compared with low-top shoes. Tied laces significantly reduced peak tension for low-top (3.7%) and high-top (12.8%) shoes when compared with untied laces. With tied laces, high-top shoes significantly reduced peak dorsiflexion angle by an average of 7.2% when compared with low-top shoes. Tied laces with high-top shoes significantly reduced peak dorsiflexion angle by an average of 4.7% when compared with untied laces. A P value of 0.05 was determined to be significant.


CONCLUSIONS
This study offers valuable insight that footwear can affect Achilles tendon loading during dorsiflexion.
Rowson
Steven
S
Center for Injury Biomechanics, Virginia Tech-Wake Forest University, Blacksburg, VA, USA. srowson@vt.edu
McNally
Craig
C
Duma
Stefan M
SM
D000125:Achilles Tendon; D000368:Aged; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012775:Shoes; D016474:Weight-Bearing