Ribcage compressibility in living subjects.

Area of Science:

• Biomechanics
• Thoracic biomechanics
• Human physiology

Background:

• Biomechanical models of the thoracic spine require validation against living subject data.
• Understanding ribcage mechanics is essential for accurate model development.
• Previous studies often rely on cadaveric data, which may not fully represent living tissue properties.

Purpose of the Study:

• To quantify the anteroposterior (AP) compressibility of the living human ribcage.
• To compare the stiffness of living ribcages with previously published cadaveric data.
• To provide experimental data for the validation of thoracic biomechanical models.

Main Methods:

• Seventeen healthy adult subjects (25-37 years) underwent slow oscillatory loading.
• Measurements were taken during breath-holding at the end of normal expiration.
• Anteroposterior forces were applied to the ribcage to determine stiffness.

Main Results:

• The mean stiffness coefficient of the living ribcage was 9.4 N/mm (SD 2.9).
• The mean gradient of the force-strain relation was 1888 N (SD 646).
• Living ribcage stiffness was found to be approximately three times less than embalmed cadavers but comparable to fresh cadavers.

Conclusions:

• Living human ribcages exhibit distinct mechanical properties compared to embalmed cadavers.
• The data generated is suitable for validating computational models of the thorax.
• This research bridges the gap between cadaveric studies and the biomechanics of living subjects.