There is.
This is a picture from chakras diagrams under the information column on the satanic meditation page:
https://satanisgod.org/www.angelfire.com/empire/serpentis666/3_Graces_by_RAFFAELLO_1504.jpg
Meditating on the knee chakras is even referenced in this meditation:
https://satanisgod.org/www.angelfire.com/empire/serpentis666/Aura_Empowering_Meditation.html
Our whole body is wrapped up with Major and Minor Chakras.
Losing any body part can be bad as it unbalances the energies and damages the Nadis and Chakras(not sure about the Chakras) but it's not game over, you can still advance but I don't know about difficulties. If one is already handicapped, don't worry, just advance. And those who aren't must be cautious, not stupid and avoid becoming a cripple, handicapped or whatever you call it because your physical health is as necessary as defeating the Jews.
1 healthy SS = 10 Jews rotting to death with illnesses, or even a 100(depending on how powerful one is).