A simple method to determine body segment masses in vivo: reliability, accuracy and sensitivity analysis

Area of Science:

• Biomechanics
• Human Movement Analysis
• Anthropometry

Background:

• Accurate inertial parameters are vital for precise joint moment calculations in clinical assessments.
• Existing literature data may not apply to diverse populations like the elderly, obese, or those with medical conditions.
• Direct measurement of inertial parameters benefits these special populations.

Purpose of the Study:

• To validate the use of force plates for rapid acquisition of subject-specific segment mass data.
• To compare force plate-derived segment masses with established published data.
• To assess the reproducibility and applicability of the force plate technique across different populations.

Main Methods:

• In vivo measurements were conducted on female varsity swimmers, female varsity volleyball players, and male college students.
• Subjects lay on a board on a force plate, adopting various limb positions to record center of pressure data.
• Limb masses were calculated from center of pressure data, utilizing estimated center of mass locations.

Main Results:

• The force plate method exhibited high reproducibility, with an average reliability coefficient of 0.83.
• Results obtained using the force plate technique were comparable to those from published methods.
• Significant differences in mass distribution were observed between female swimmers and volleyball players (P<0.025).

Conclusions:

• The force plate method provides a rapid and reliable means to obtain subject-specific limb segment mass information.
• Individualized segment mass data enhances the accuracy of clinical assessments.
• This technique is essential for special populations to prevent erroneous biomechanical conclusions.