Abstract
Background
The last several years have seen an increased interest in elucidating the causes of
non-traumatic injuries specific to bicyclists. Injuries may include soreness of the
pelvis, skin problems in the groin, erectile dysfunction, and impotence. Combined
loading at the seat may be contributing factors to these injuries.
Methods
Vertical and shear loads were collected for 10 subjects cycling at 75 crank revolutions
per minute (RPM) in a common fit position. External workload was held constant at
125 watts while force data were collected using a multi-axis load cell integrated
under the seat of a standard bicycle. The crank arm angles at which the maximum forces
occurred were obtained using a motion analysis system, and regions of rider contact
with the seat were visualized with a pressure mapping system.
Findings
Measured vertical loads at the seat were greater than shear loads. Maximum mean vertical
loads of 49–52% body weight, rearward shear loads of 11–12% body weight, and lateral
shear loads of 4–5% body weight occurred at the seat. Associated timing angles referenced
to the pedal position were also measured and averaged at the maximum and minimum loads.
Interpretation
Seat pressure mapping and blood flow have previously been used to study the interaction
between bicyclists and their seats. This investigation focused on shear and vertical
seat loads that may be contributing factors in injuries at the groin.
Keywords
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Article info
Publication history
Published online: August 20, 2007
Accepted:
June 26,
2007
Received:
December 6,
2006
Identification
Copyright
© 2007 Elsevier Ltd. Published by Elsevier Inc. All rights reserved.
