Article

Although not well understood, foot kinematics are changed with hallux valgus.
The purpose of this study was to examine tarsal kinematics in
women with hallux valgus deformity.
DESIGN: A prospective, cross-sectional design
was used. METHODS: Twenty women with (n=10) and without (n=10) deformity
participated. Data were acquired with the use of a magnetic resonance scanner.
Participants were posed standing to simulate gait, with images reconstructed into
virtual bone datasets. Measures taken described foot posture (hallux angle,
intermetatarsal angle, arch angle). With the use of additional computer
processes, the image sequence was then registered across gait conditions to
compute relative tarsal position angles, first-ray angles, and helical axis
parameters decomposed into X, Y, and Z components. An analysis of variance model
compared kinematics between groups and across conditions. Multiple regression
analysis assessed the relationship of arch angle, navicular position, and
inclination of the first-ray axis. RESULTS: Both the hallux and intermetatarsal
angles were larger with deformity; arch angle was not different between groups.
The calcaneus was everted by >/=6.6 degrees, and the first ray adducted (F=44.17)
by >/=9.3 degrees across conditions with deformity.
There was an interaction
(F=5.06) for the first-ray axis. Follow-up comparisons detected increased
inclination of the first-ray axis over middle stance compared with late stance in
the group with deformity. LIMITATIONS: Gait was simulated, kinetics were not
measured, and sample size was small. CONCLUSIONS:
There were group differences.
Eversion of the calcaneus and adduction of the first ray were increased, and the
first-ray axis was inclined 24 degrees over middle stance in women with deformity
compared with 6 degrees in control participants. Results may identify risk
factors of hallux valgus and inform nonoperative treatment (orthoses, exercise)
strategies.

Langue : ANGLAIS