Chapter 12, Problem 7A

What are the three principal axes of rotation for the human body?

To determine

The three principal axis of rotation of the human body.

Answer to Problem 7A

The three principal axis of rotation of human body are longitudinal axis, transverse axis, and medial axis.

Explanation of Solution

Introduction:

The human body is flexible and can be rotated freely about any of the three principal axis namely longitudinal, transverse and medial axis in order to execute actions such as flip, exercise, and other daily works.

The three principal axis of rotation of the human body are longitudinal axis, medial axis, and transverse axis.

The principal axis of rotation of the human body is shown below.

  

Figure 1

The three principal axes are mutually perpendicular to each other and pass through the centre of gravity.

The longitudinal axis is the vertical axis which passes through the head to the toe of the human body. The ice skaters usually rotate about the longitudinal axis as the rotational inertia is minimum in this case.

The transverse axis is the horizontal axis about which human rotates in order to execute a somersault or a flip.

The medial axis is the horizontal axis about which human rotates in order to execute gymnastic such as cartwheel.

Conclusion:

Thus, the three principal axis of rotation of human body are longitudinal axis, transverse axis, and medial axis.