Differences and mechanisms
the knee-GRF lever arm, rather than lower limb
kinematics or the sagittal plane resultant GRF
magnitude wearing shoes compared to barefoot.
This novel finding suggests that future footwear
modifications aiming to reduce peak KFM
should consider shoe design features that have
the potential to reduce the knee-GRF lever arm.
Specifically, footwear pitch (i.e., the heel to toe
offset, [17] ) and midsole density/compliance may
be important features contributing to difference
in the knee-GRF lever arm.
Harder and/or thicker midsoles may contribute
to alterations of the knee GRF lever arm wearing
shoes compared to barefoot, as previous
research indicates that thicker midsoles can
reduce plantar sensation [30] , and can lead to
higher knee flexion kinetics and kinematics [21] .
30
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Although we did not measure midsole thickness,
we recommend that future studies investigate
the influence of midsole thickness on the knee-
GRF lever arm in this population.
Footwear pitch may also have contributed to
the knee-GRF lever arm findings, as both the
stability and neutral shoes we tested possessed
13 mm and 10 mm heel to toe offsets respectively,
compared to 0 mm while barefoot. Although
no studies have examined the relationship
between pitch and change in peak KFM or
the knee-GRF lever arm, lowering the pitch of
shoes may indeed influence these parameters
by reducing ankle dorsiflexion and knee flexion
angles towards barefoot levels. Support for
this theory is provided by Lindenberg et al.
(2011) who explored the association between