Compressive and shear hip joint contact forces are affected by pediatric obesity during walking

Abstract

Obese children exhibit altered gait mechanics compared to healthy-weight children and have an increased prevalence of hip pain and pathology. This study sought to determine the relationships between body mass and compressive and shear hip joint contact forces during walking. Kinematic and kinetic data were collected during treadmill walking at 1 m•s−1 in 10 obese and 10 healthy-weight 8–12 year-olds. We estimated body composition, segment masses, lower-extremity alignment, and femoral neck angle via radiographic images, created personalized musculoskeletal models in OpenSim, and computed muscle forces and hip joint contact forces. Hip extension at mid-stance was 9° less, on average, in the obese children (p<0.001). Hip abduction, knee flexion, and body-weight normalized peak hip moments were similar between groups. Normalized to body-weight, peak contact forces were similar at the first peak and slightly lower at the second peak between the obese and healthy-weight participants. Total body mass explained a greater proportion of contact force variance compared to lean body mass in the compressive (r2=0.89) and vertical shear (perpendicular to the physis acting superior-to-inferior) (r2=0.84) directions; lean body mass explained a greater proportion in the posterior shear direction (r2=0.54). Stance-average contact forces in the compressive and vertical shear directions increased by 41 N and 48 N, respectively, for every kilogram of body mass. Age explained less than 27% of the hip loading variance. No effect of sex was found. The proportionality between hip loads and body-weight may be implicated in an obese child’s increased risk of hip pain and pathology.

A systematic review on biomechanical characteristics of walking in children and adolescents with overweight/obesity: Possible implications for the development of musculoskeletal disorders

“…Analysing the whole gait cycle, there was moderate evidence indicating that OW/OB have higher activation and generate higher forces with gastrocnemius and soleus muscles compared with NW . On the other hand, there was moderate evidence supporting no differences between OW/OB and NW on quadriceps and hamstring muscle activations and forces, respectively. The remaining muscles studied in the gait pattern of OW/OB and NW were inconsistent (ie, gluteus complex) or insufficient (ie, psoas, iliacus, and tibialis anterior).…”

“…With regard to kinetic parameters, there was strong evidence supporting higher hip flexion, extension and abduction moments and power generation/absorption in OW/OB compared with NW . Kinetics of transversal plane showed inconsistent evidence, while there was insufficient evidence, with only one study available, to determine differences between OW/OB and NW in terms of contact forces acting on the femoral head during walking.…”

“…To date, one of the main limitations of gait analysis in OW/OB is the presence of soft tissue artefacts in the data, especially around the pelvis and thigh where this population accumulates greater adiposity . Only studies of Briggs et al, Lerner and Browning, Lerner et al, and Strutzenberger et al addressed soft tissue artefacts, by using virtual markers relative to anatomical structures less likely to present adiposity (eg, the sacrum) or by measuring the distance between anatomical landmarks (eg, left and right anterior superior iliac spines) in order to recreate the adequate position of markers. Possibly this limitation, together with the use of different methodologies to measure kinematic and kinetic parameters, can partially explain the inconsistencies observed at the pelvis and hip.…”

“…Possibly this limitation, together with the use of different methodologies to measure kinematic and kinetic parameters, can partially explain the inconsistencies observed at the pelvis and hip. We could only identify one study that investigated the influence of paediatric obesity on hip joint contact forces during walking . Lerner and Browning found that OW/OB are exposed to higher femoral head forces in compressive and anterior‐posterior directions compared with NW during the gait pattern.…”

“…We could only identify one study that investigated the influence of paediatric obesity on hip joint contact forces during walking . Lerner and Browning found that OW/OB are exposed to higher femoral head forces in compressive and anterior‐posterior directions compared with NW during the gait pattern. Further research is warranted to confirm these higher hip contact forces in OW/OB and to propose gait analysis procedures to minimize soft tissue artefacts in this specific population.…”