Article

Little is known about hip joint stiffness during walking (dynamic
joint stiffness) and the effect of hip impairments on biomechanical alterations
of other joints in patients with total hip arthroplasty. METHODS: Twenty-four
patients (mean age 61.7 years) who underwent unilateral (n=12) or bilateral total
hip arthroplasty (n=12) and healthy subjects (n=12) were recruited. In addition
to kinematic and kinetic variables, dynamic hip joint stiffness which was
calculated as an angular coefficient of linear regression of the plot of the hip
flexion moment vs. hip extension angle during the late stance of gait, was
measured. Group differences were compared using one-way ANOVA and Tukey's
post-hoc test, and relationships between primary hip impairments and secondary
gait impairments were found using partial correlation coefficients adjusted for
gait speed and stride length. FINDINGS: Dynamic hip joint stiffness was 47%
higher on the side with the more pronounced limp in patients with bilateral
arthroplasty than in healthy controls. In the same patients, increased dynamic
hip joint stiffness was significantly associated especially with increased ankle
plantarflexion moment on the ipsilateral side. In patients with unilateral
arthroplasty, decreased hip power was significantly related to increased ankle
plantarflexor power, only on the non-operated side. INTERPRETATION: We found that
dynamic hip joint stiffness was an important factor in assessing relationships
between hip impairments and dynamics in other joints, especially in patients with
bilateral total hip arthroplasty. The effects of altering hip joint stiffness on
gait biomechanics need to be explored.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS