Finite element analysis of the stump-ischial containment socket interaction: a technical note

Area of Science:

• Biomechanics
• Prosthetics Engineering
• Computational Modeling

Background:

• Above-knee prosthetic sockets transfer load from the residual limb to the prosthesis.
• Accurate socket fit is crucial for comfort and preventing soft tissue damage.
• Current models often neglect the hip joint's complex biomechanics and muscle forces.

Purpose of the Study:

• To develop a novel modeling framework incorporating the hip joint and muscle forces for above-knee socket analysis.
• To investigate the influence of ischial support on muscle activity and interface pressure.
• To validate the model's predictions against experimental data.

Main Methods:

• A combined MusculoSKeletal (MSK) and Finite Element (FE) modeling framework was developed.
• An experimental-numerical approach was applied to a single femoral amputee subject.
• Hip joint modeling, personalized muscle force estimation, and interface pressure evaluation were performed.

Main Results:

• The model successfully integrated hip joint biomechanics and estimated muscle forces.
• A reduction in gluteus medius force was observed when ischial support was considered.
• Predicted interface pressures (63-71 kPa) aligned with existing literature data.

Conclusions:

• Incorporating the hip joint is essential for accurate prediction of socket interface pressure.
• The combined MSK/FE framework provides a valuable tool for prosthetic socket design and optimization.
• This approach enhances understanding of residual limb-prosthesis interaction for improved patient outcomes.