Late rearfoot eversion and lower-limb internal rotation caused by changes in the interaction between forefoot and support surface.
BACKGROUND
The influence of distal mechanical factors that change the interaction between the forefoot and the support surface on lower-limb kinematics is not well established. This study investigated the effects of the use of lateral wedges under the forefoot on the kinematics of the lower extremity during the stance phase of walking.


METHODS
Sixteen healthy young adults participated in this repeated-measures study. They walked wearing flat sandals and laterally wedged sandals, which were medially inclined only in the forefoot. One wedged sandal had a forefoot lateral wedge of 5 degrees and the other wedged sandal had a forefoot lateral wedge of 10 degrees. Kinematic variables of the lower extremity, theoretically considered clinically relevant for injury development, were measured with a three-dimensional motion analysis system. The variables were evaluated for three subphases of stance: loading response, midstance, and late stance.


RESULTS
The 5 degrees laterally wedged sandal increased rearfoot eversion during midstance and the 10 degrees laterally wedged sandal increased rearfoot eversion during mid- and late stances, in comparison to the use of flat sandals. The 10 degrees laterally wedged sandal produced greater internal rotation of the shank relative to the pelvis and of the hip joint, during the midstance, also compared to the use of flat sandals.


CONCLUSIONS
Lateral wedges under the forefoot increase rearfoot eversion during mid-and late stances and may cause proximal kinematic changes throughout the lower-extremity kinetic chain. Distal mechanical factors should be clinically addressed when a patient presents late excessive rearfoot eversion during walking.
Souza
Thales R
TR
Department of Physical Therapy, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. thalesrsouza@gmail.com
Pinto
Rafael Z
RZ
Trede
Renato G
RG
Kirkwood
Renata N
RN
Pertence
Antônio E
AE
Fonseca
Sérgio T
ST
D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D005545:Forefoot, Human / Q000502:physiology*; D005684:Gait / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D016138:Walking / Q000502:physiology*; D055815:Young Adult