Effect of simulated changes in pelvic tilt on hip joint forces

Area of Science:

• Biomechanics
• Musculoskeletal Modeling
• Orthopedics

Background:

• Musculoskeletal modeling simulates movements and compares individuals.
• Femoroacetabular impingement syndrome (FAIS) is associated with increased anterior pelvic tilt during gait.
• The impact of pelvic tilt adjustments on muscle and joint forces in modeling is not well understood.

Purpose of the Study:

• To investigate how altering pelvic tilt affects muscle and hip joint forces in musculoskeletal models.
• To determine if accounting for pelvic tilt is necessary for accurate gait simulations in conditions like FAIS.

Main Methods:

• Gait data from six participants were collected and processed.
• Pelvic tilt was adjusted by ±10° across three conditions: no adjustment, posterior tilt, and anterior tilt.
• Muscle and femur-on-acetabulum joint forces were calculated using OpenSim and analyzed with statistical parametric mapping.

Main Results:

• Shifting from posterior to anterior pelvic tilt reduced overall resultant forces.
• Anterior pelvic tilt decreased anteriorly-directed joint forces and increased medially-directed forces in the pelvic frame.
• Anterior pelvic tilt increased anterior and medial joint forces, while decreasing superior forces in the femoral frame, with notable changes in specific hip muscles.

Conclusions:

• Pelvic tilt significantly influences calculated muscle and joint forces in musculoskeletal models.
• Future musculoskeletal modeling studies should incorporate pelvic tilt adjustments for more realistic gait analysis, especially for pathological conditions like FAIS.