• Apparent mass of seated human body

Posted: **Sun Jul 14, 2024 1:46 pm**

The equation:

$M(\omega) = \frac{force\:at\:seat\:person\:interface}{acceleration\:at\:seat-person\:interface$

$M(\omega) = \frac{F_1(\omega)}{A_p(\omega)}$

$M(\omega) = \frac{F_1(\omega) - m_1 A_s(\omega) - m_2 A_p(\omega)}{A_p(\omega)}$

$$M(\omega)$: Apparent mass (frequency domain)$
$$F_1(\omega)$: Force at seat-person interface$
$$A_p(\omega)$: Acceleration at seat-person interface$
$$A_s(\omega)$: Seat acceleration$
$$m_1$: Lower body mass$
$$m_2$: Upper body mass$

Posted: **Tue Aug 18, 2026 4:01 pm**

Definition of Apparent Mass

Apparent mass of a person is the frequency-dependent inertial mass that an external vibrating support “feels” when it excites the body. In whole-body vibration studies, it quantifies how strongly a seated or standing person reacts dynamically to seat, floor, or platform acceleration.