and now patanjali gets down to the nuts and bolts of the thing : the eight limbs of yoga are : the various forms of abstention from evildoing ( yama ) , the various observances ( niyamas ) , posture ( asana ) , control of the prana ( pranayama ) , withdrawal of the mind from sense objects ( pratyahara ) , concentration ( dharana ) , meditation ( dhyana ) , and absorption in the atman ( samadhi ) .