Similar to Hatha or Restorative Yoga, Yin Yoga, so named because of its connection to Chinese medicine, uses long-held physical postures to create certain desired benefits: Physical and physiological, Energetic, Emotional and Mental, as well as Spiritual and meditative.
The focus of Yin Yoga postures is to maintain or restore elasticity of the connective tissue in the large joints in the body, namely the hips, lower back and pelvis. Yin Yoga posits that the body's joint (or connective) tissue--the so-called "yin" or passive, receptive tissue --hardens over time, making movement more difficult with age. Yin Yoga targets the connective tissue by holding postures that slowly stretch the deeper tissues in the body in order to keep the body supple.
Yin is particularly beneficial as a compliment to a strong “Yang” practice (Ashtanga, Hatha, etc.) Yin can help students attain a deeper degree of flexibility in the joints and as such aids the student in advancing their regular practice.