If you have been diagnosed with an L5/S1 herniation and had an MRI, you should not be doing any karate kicks or jumps at all. You are doing more damage and increasing the herniation.

What you should be doing is going to physical therapy in an attempt to heal the herniation.

With a physical therapist you will learn how to properly strengthen your core muscles that are vital for good support of your spine, how to move properly, bend, turn, twist and stoop.

The foot numbness is a strong indication of nerve compression. Whether it has developed into permanent nerve damage or not, only your spine surgeon can tell you that.

Continued nerve compression can result in permanent nerve damage, how long that takes to happen is an individual thing.

Continuing to any kind of exercise that will prevent the disc herniation from healing, potentially making it worse, can and will result in permanent damage.

Are you being followed by a spine surgeon? If not then you need to be evaluated by one right away and follow the advise of your doctor.

Good luck

Fran