TY - JOUR
T1 - Does adiposity affect muscle function during walking in children?
AU - Lerner, Zachary F.
AU - Shultz, Sarah P.
AU - Board, Wayne J.
AU - Kung, Stacey
AU - Browning, Raymond C.
N1 - Funding Information:
This study was funded internally by the Massey University Research Fund (Grant no. RM15980).
Publisher Copyright:
© 2014 Elsevier Ltd.
PY - 2014/9/22
Y1 - 2014/9/22
N2 - The biomechanical mechanisms responsible for the altered gait in obese children are not well understood, particularly as they relate to increases in adipose tissue. The purpose of this study was to test the hypotheses that as body-fat percentage (BF%) increased: (1) knee flexion during stance would decrease while pelvic obliquity would increase; (2) peak muscle forces normalized to lean-weight would increase for gluteus medius, gastrocnemius, and soleus, but decrease for the vasti; and (3) the individual muscle contributions to center of mass (COM) acceleration in the direction of their primary function(s) would not change for gluteus medius, gastrocnemius, and soleus, but decrease for the vasti. We scaled a musculoskeletal model to the anthropometrics of each participant (. n=14, 8-12 years old, BF%: 16-41%) and estimated individual muscle forces and their contributions to COM acceleration. BF% was correlated with average knee flexion angle during stance (. r=-0.54, p=0.024) and pelvic obliquity range of motion (. r=0.78, p<0.001), as well as with relative vasti (. r=-0.60, p=0.023), gluteus medius (. r=0.65, p=0.012) and soleus (. r=0.59, p=0.026) force production. Contributions to COM acceleration from the vasti were negatively correlated to BF% (vertical- r=-0.75, p=0.002, posterior- r=-0.68, p=0.008), but there were no correlation between BF% and COM accelerations produced by the gastrocnemius, soleus and gluteus medius. Therefore, we accept our first, partially accept our second, and accept our third hypotheses. The functional demands and relative force requirements of the hip abductors during walking in pediatric obesity may contribute to altered gait kinematics.
AB - The biomechanical mechanisms responsible for the altered gait in obese children are not well understood, particularly as they relate to increases in adipose tissue. The purpose of this study was to test the hypotheses that as body-fat percentage (BF%) increased: (1) knee flexion during stance would decrease while pelvic obliquity would increase; (2) peak muscle forces normalized to lean-weight would increase for gluteus medius, gastrocnemius, and soleus, but decrease for the vasti; and (3) the individual muscle contributions to center of mass (COM) acceleration in the direction of their primary function(s) would not change for gluteus medius, gastrocnemius, and soleus, but decrease for the vasti. We scaled a musculoskeletal model to the anthropometrics of each participant (. n=14, 8-12 years old, BF%: 16-41%) and estimated individual muscle forces and their contributions to COM acceleration. BF% was correlated with average knee flexion angle during stance (. r=-0.54, p=0.024) and pelvic obliquity range of motion (. r=0.78, p<0.001), as well as with relative vasti (. r=-0.60, p=0.023), gluteus medius (. r=0.65, p=0.012) and soleus (. r=0.59, p=0.026) force production. Contributions to COM acceleration from the vasti were negatively correlated to BF% (vertical- r=-0.75, p=0.002, posterior- r=-0.68, p=0.008), but there were no correlation between BF% and COM accelerations produced by the gastrocnemius, soleus and gluteus medius. Therefore, we accept our first, partially accept our second, and accept our third hypotheses. The functional demands and relative force requirements of the hip abductors during walking in pediatric obesity may contribute to altered gait kinematics.
KW - Biomechanics
KW - Clinical gait pathology
KW - Musculoskeletal modeling
KW - Pediatric obesity
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U2 - 10.1016/j.jbiomech.2014.07.006
DO - 10.1016/j.jbiomech.2014.07.006
M3 - Article
C2 - 25064426
AN - SCOPUS:84908062978
SN - 0021-9290
VL - 47
SP - 2975
EP - 2982
JO - Journal of Biomechanics
JF - Journal of Biomechanics
IS - 12
ER -