Maintaining the integrity of pelvic alignment during yogasana is of great importance, otherwise you are at risk of developing an injury, such as those in the sacroiliac joint (SIJ). While no particular movement is inherently ‘bad’, it is unsafe to practice any movement repeatedly using poor alignment. Students who are prenatal, postnatal, golfers or sleep on the same side every night are more prone to SIJ injuries.
SIJ injuries display as a sharp pain in the lower back and it generally denotes a tear in the ligaments holding one side of the sacrum and ilium together. These ligaments are avascular which means it will take a very long time to heal from the poor circulation to the area. Once you have injured the SIJ you are more likely to injure it again, but this issue can be managed post recovery using a modified practice. Too many asymmetrical poses on one side can cause pelvic instability unless direct and correct alignment and adjustment is taught for all parts of the body to avoid twisting, tugging and torquing of the SIJ. It is imperative to stretch and strengthen equally on both sides of the body, as well as holding poses for the same length of time on each side. It is critical to be sufficiently prepared and warmed for any advanced yoga poses (especially teachers who demonstrate without warming up first). Using the hands to forcibly lever yourself deeper in poses like Janu Sirsasana is a no-no, as it is advisable to hinge from the pelvis and keep the heart shining forwards. Encourage students to bend the knees in Uttanasana if needed, then the sacrum and pelvis are free to move in the same direction, as the sacrum will move in the direction of the load (torso pulling forward and down). Poses like prone backbends (e.g. Salabhasana) are the most stable position for the hips as they strengthen the muscles above and below. These can help to stabilize the sacrum.
It is also essential to incorporate bandhas throughout your practice - namely mula bandha (root lock) and uddiyana bandha (abdominal lock) - to activate the band of muscles around the thoracic and lumbar spine, and pelvic girdle to protect and strengthen the joints, ligaments, tendons and connective tissues. Pada bandha (foot lock) is also important as you draw up from the arches of the feet - in a radiating fashion from the floor up - you are activating the muscles of the lower leg, the adductors, the pelvic floor (mula bandha) and the transverse abdominus (uddiyana bandha).
In addition, It is equally important to remember to strengthen and stretch each muscle during yogasana to avoid overly tight or overly lengthened muscles. Excessively strong or weak muscles can potentially lead to injury.
By Alyssa McLeod
Ray Long, 2009. The Key Muscles of Yoga: Scientific Keys, Volume I. 3 Edition. BandhaYoga.
Sequence Wiz. 2016. Too many asymmetrical poses can create sacroiliac joint issues. [ONLINE] Available at: http://sequencewiz.org/2014/02/20/too-many-asymmetrical-poses-can-create-sacroiliac-joint-issues/. [Accessed 29 September 2016].