Human Biophysics

Human biophysics explores the physical principles that govern bodily form, function and adaptation. Spanning scales from molecular interactions and fluid transport in tissues to whole‐body mechanics and neural integration, the field unites quantitative imaging, computational modelling and experimental biomechanics. It addresses how cells sense and respond to mechanical forces, how soft tissues exhibit viscoelastic behaviour under load, how fluid shifts in microgravity or disease affect cardiovascular and neuro‐ocular health, and how vibration transmits through the body to influence comfort and injury risk. By integrating physics, physiology and engineering, human biophysics informs ergonomic design, spaceflight countermeasures, diagnostic imaging, rehabilitation and our understanding of health and disease.

Research from Nature Portfolio

A five‐day dry immersion study in healthy women replicated acute microgravity and revealed an early metabolic syndrome‐like profile, featuring reduced glucose tolerance, unfavourable lipid alterations and a rise in the atherogenic index. Concurrently, bone remodelling markers showed decreased formation and increased resorption, while muscle unloading and fluid shifts led to diminished orthostatic tolerance, aerobic capacity and postural stability, underscoring the need for sex‐specific countermeasures in long‐duration missions.

A four‐degree‐of‐freedom human–chair coupling model has been validated against seat‐to‐head transfer ratio measurements, demonstrating that targeted backrest supports reduce peak biodynamic transmissibility by up to 21 % when optimally tuned for stiffness and damping. These findings guide the design of seating systems to mitigate whole‐body vibration exposure and prevent musculoskeletal strain.

Human Biophysics publication trend

The graph below shows the total number of articles in human biophysics across all publications each year (not limited to Nature Index journals).

Technical terms

Dry immersion: Ground‐based model simulating weightlessness by suspending subjects in water without direct contact, inducing rapid mechanical unloading.

Seat‐to‐head transfer ratio (STHT): Ratio of head acceleration amplitude to input vibration at the seating interface, used to quantify biodynamic transmissibility.

Lower body negative pressure (LBNP): Technique applying sub‐atmospheric pressure around the lower torso to shift fluids caudally, counteracting headward redistribution.

Atherogenic index of plasma: Logarithmic ratio of triglycerides to HDL cholesterol, indicating the propensity of a lipid profile to promote atheroma formation.

Resonant frequency: Frequency at which a system’s vibrational amplitude is maximal due to minimal net impedance.

Vibrational transmissibility: Measure of vibration transmission through a medium, expressed as the output/input acceleration ratio.

Jugular venous stasis: Impaired or reversed flow in the internal jugular veins, leading to elevated intracranial venous pressure and thrombosis risk.

References

1. Assessment of Jugular Venous Blood Flow Stasis and Thrombosis During Spaceflight. JAMA Network Open (2019).
2. Comprehensive assessment of physiological responses in women during the ESA dry immersion VIVALDI microgravity simulation. Nature Communications (2023).
3. Vibration reduction of human body biodynamic response in sitting posture under vibration environment by seat backrest support. Scientific Reports (2024).
4. Real‐time vibration monitoring and analysis of agricultural tractor drivers using an IoT‐based system. Journal of Field Robotics (2023).
5. Simulation and experimental study on the stability and comfortability of the wheelchair human system under uneven pavement. Frontiers in Bioengineering and Biotechnology (2023).