1st Joint ESMAC-GCMAS Meeting - Análise de Marcha

O-16
RELATIONSHIP BETWEEN THE ANTHROPOMETRIC VARIABLES AND
FRONTAL KNEE MOMENTS IN HEALTHY OBESE ADULTS.
Khole Priyanka 1 , Segal Neil, MD 2 , Yack H John, PT PhD 1
1 Graduate Program in Physical Therapy and Rehabilitation Sciences, University of Iowa, Iowa,
USA.
2 Department of Orthopedics and Rehabilitation, University of Iowa, Iowa, USA.
Summary/conclusions
Increased body weight has been proposed as a risk factor for the development of knee OA.
The relationship between body mass and the frontal plane knee moment, however, is only
moderate. The knee moment is also influenced by individual anthropometric characteristics
that help to define the distribution of mass.
Introduction
Osteoarthritis (OA) is a leading cause of disability among US adults causing pain, joint
stiffness and limited mobility[1]. Obesity has been identified as an important modifiable risk
factor contributing to both the development [2] and progression of knee OA [3]. Researchers
believe that although obesity may be affecting the pathogenesis of knee OA through both
biochemical and biomechanical pathways, mechanical loading of the articular cartilage is of
primary importance. Obese women have an increased prevalence of knee OA compared to men
[4]. In addition, gender differences in obesity patterns and other anthropometric variables have
been documented. This raises the possibility of associations between body anthropometrics
and altered gait biomechanics that put certain obese adults at an increased risk of developing
knee OA [5].The external knee adduction moment (EKAM), thought to be a contributor to
medial compartment knee OA [6], provides a good estimate of knee joint loading. Correlating
EKAM with anthropometric variables, such as waist, hip, thigh, gluteal furrow circumferences
of obese adults could help to uncover associations that might be useful in identifying obese
populations at risk of developing knee OA.
Statement of clinical significance
Over 70% of US adults are either overweight or obese and thus at a higher risk for developing
knee OA [7]. Trying to identify issues that affect loading at the knee in this population may
help to identify intervention strategies that can be used to affect the incidence of OA in this
population.
Methods
Sixty subjects, twenty normal weight controls, twenty subjects with a lower obese pattern and
twenty subjects with a central obesity pattern, between the ages of 35-55 years and with no
knee, lower limb, neuromuscular or medical problems participated in the study. Obesity was
defined as having a body mass index (BMI) greater than or equal to 30.0 Kg/m 2 (BMI of
controls < 25.0 Kg/m 2 ). Women with waist:hip (W:H) ratio of 0.85 or less and men with a ratio
of 0.95 or less were identified to have lower obesity patterns. Anthropometric variables of
height, weight and waist, hip, mid-thigh, gluteal furrow circumferences were measured as per a
set protocol. Standard kinetic and kinematic data was collected using an Optotrak motion
analysis system and Kistler force plate as the subjects walked along a 10 m walkway at their
self selected speed. Three non-collinear markers were used to track the right lower limb, pelvis
and trunk. Kinematic data were collected at 60 Hz and filtered at 6 Hz. Frontal plane data were
analyzed using Visual 3D (C-Motion, Inc) to obtain the external knee adduction moments.
Inter-group comparisons were made using a One-way ANOVA and Pearson’s correlation
coefficients were calculated to assess associations.
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