Beinmasse

Beinmasse is a term used in biomechanics and anatomy to denote the mass of a human leg, including the thigh, lower leg, and foot. In biomechanical analyses it is treated as a distinct segment with a defined mass, center of mass, and moments of inertia, and it is used in models of movement such as gait analysis and inverse dynamics. The leg is commonly modeled as three linked segments—thigh, shank, and foot—each with its own mass and local center of mass.

Measurement and estimation methods vary. Direct measurement can be obtained in cadaveric samples, while in living individuals mass is typically estimated through imaging-based approaches such as magnetic resonance imaging or computed tomography to segment tissues and estimate segment mass. Dual-energy X-ray absorptiometry can provide lean soft tissue mass for leg segments, and anthropometric methods use limb lengths, circumferences, and skinfolds with regression equations. Dynamic methods combine motion capture with musculoskeletal modeling to estimate segment parameters in vivo.

Purpose and applications. Beinmasse is important for understanding the mechanics and energetics of movement, informing rehabilitation and orthotic or prosthetic design, and guiding athletic training and performance analysis. It is also relevant in robotics and exoskeleton development where leg dynamics are modeled for control.

Variability and limitations. There is substantial inter-individual variation in leg mass and distribution, influenced by age, sex, body composition, and training. Measurement errors and modeling assumptions can affect estimates, especially in clinical or performance contexts. See also biomechanics, body composition, and gait analysis.