In most gyms, you’ll see people doing knee-ins with a medicine ball or dumbbell held between their feet. While that adds resistance, it also forces the hip flexors to work overtime just to keep the weight elevated — because the resistance is vertical.

A smarter alternative is to use horizontal resistance with a low-pulley cable. This aligns the resistance with the actual direction of movement, making the exercise more effective and reducing unnecessary hip flexor strain.

This video demonstrates three cable attachment options for low-pulley knee-ins.
For more details, check out: https://theelitetrainer.com/low-pulley-knee-in/