Influence of muscle groups' activation on proximal femoral growth tendency

Area of Science:

• Biomechanics
• Pediatric Orthopedics
• Developmental Biology

Background:

• Muscle and joint forces impact the proximal femur's growth plate, influencing bone development and skeletal alignment.
• Key developmental parameters like neck shaft angle (NSA) and femoral anteversion (FA) are sensitive to these biomechanical stresses.

Purpose of the Study:

• To investigate how the activation of specific hip and knee muscle groups during gait influences the development of NSA and FA in healthy children.
• To quantify the contribution of individual muscle groups to hip contact forces and their subsequent effect on bone growth simulation.

Main Methods:

• Developed subject-specific femur models for three children (ages 6, 7, 11) using MRI data.
• Calculated muscle group contributions to hip contact force and simulated bone growth based on computed stress directions.
• Analyzed the impact of muscle activation on NSA and FA over a simulated four-month period.

Main Results:

• Predicted decreases in NSA and FA in able-bodied children, averaging approximately [Formula: see text] over four months.
• Hip abductors demonstrated the largest influence on growth rate, while hip adductors had the least.
• Most muscle groups decreased predicted NSA and FA, with hip extensors and adductors showing a tendency to increase FA.

Conclusions:

• Muscle activation patterns during gait play a crucial role in shaping long bone morphology during childhood.
• Understanding these muscle-bone interactions is vital for developing targeted interventions for pediatric gait abnormalities.
• Differential contributions of muscle groups highlight specific targets for therapeutic strategies in pediatric orthopedic care.