I came across a curious question today – “what is the symbolic meaning of tight feet”? This individual was also looking for a modification to Janu Sirsasana C.
In my experience, tight feet are unable to receive support from the earth. This tight holding blocks the feminine, magnetic, “earth” energy (which provides a sense of grounding) from flowing up and enlivening your legs and core. Your lower body is associated with the root chakra located at the base of your spine. Energy in this centre relates to physical survival and represents your connection with the earth and the magnetic essence.
Modification for Janu C (care of David Swenson): With grounding leg extended in front, “sit up straight and rotate the (bent knee) foot in a preparatory phase without placing it on the floor. If this is too extreme then repeat Janu Sirsasana A or B”.