You must have heard about the metaphor “Grow a Spine” meaning fighting and having the courage to tackle something important. We can think of this also in terms of morals and ethics. Our lives revolve around this concept of ethics in the western worldview but in the Sanaatana Dharma (Hinduism) it is referred to as Swa Dharma or your personal Dharma. Doing the right thing as per your context/situation, time and place. Now this is not a simple task and requires a lot of courage (spine). Life presents a lot situations where you have to take a lot of decisions and make choices. This is represented by Tula Rashi where the lord of Karma Shani Bhagwan gets exalted i.e. your choices decide your karma i.e. action.
According to Kriya Yoga all the seeds of Karma are stored in the astral spine in the chakras. The techniques of Kriya Yoga involve breathing techniques with focus (Chitt) on the physical spine which is a manifestation of the astral spine from the Pranamaya Kosha (astral body). Shani Bhagwan is Vayu tattwa. The breath is an instrument thru which you access this Prana Shakthi and hence one can erase the stored Karma thru Paranayama and Kriya techniques, similar to wiping out the memory stored in computer devices.
If we consider the spine and the skeletal system in Physiology, it supports all other organs and the organism as a whole. This can be considered similar to the planets revolving around the Sun in the Solar system. Surya Bhagwan is that Swa Dharma that our lives revolve around. Hence he exalts in the Mesha Rashi, 9th (Dharma) from his own Simha Rashi.
Observe that he is always shown with a Bow. Isin’t the bow similar in shape as the Spine? This ethical/moral spine? Physically the spine cannot be straight, it has to be curved so as to absorb the stress from the movement of the body and gravity (Gurutwa). Similarly Dharma cannot be a one size fits all or straight it has to be curved like the spine based on the context (desh, kaal and paatra).
The breath is also like the action of the bow and arrow. You inhale i.e. pull back the string of the bow with arrow, focus on the target, and then release the arrow (exhale). A leader never jumps into action without assessing the situation. Its the same going back and assessing the situation i.e. inhalation and then releasing the funds/execution etc. of exhalation. Surya Bhagwan is also “Praananath” and hence the remedies of “Prana Prathishta” are given for afflictions to Surya in the natal chart. The spine is also called as the “Back Bone” or foundation to the body. Even Shani Bahgwan is shown with a Bow and Arrow, again showing the importance of this moral compass on your Karma.