Chapter 6 - Linear Momentum and Collisions - Learning Path Questions and Exercises - Conceptual Questions - Page 214: 7

When legs are stiffed, the force acts for a very short time. The force will directly reach the knees and hence hurt the knees. But when the knees are bent, the force acts for a longer time and hence the impulse is less.

When legs are stiffed, the force acts for a very short time. The force will directly reach the knees and hence hurt the knees. But when the knees are bent, the force acts for a longer time and hence the impulse is less.