When are infrared rays considered to be most intense?

Infrared rays are considered most intense when they are positioned perpendicular to the limb. This orientation allows for maximum absorption of the rays by the tissues, as the intensity of infrared radiation is directly related to the angle at which it strikes a surface. When the rays hit a surface perpendicularly, the energy is concentrated on that surface area, leading to greater effectiveness in therapeutic applications.

In other orientations, such as at an angle or in a diffuse arrangement, the energy is distributed over a larger area or may not penetrate as effectively into the tissues. Thus, positioning infrared rays perpendicular to the limb optimizes the therapeutic benefits by ensuring that more energy is delivered to the targeted area, making it the most effective setup for treatments involving infrared therapy.