Last week, the continuing and deepening classes that I teach worked on halasana (plow pose shown above). Folks were wondering why they could come into a deep forward bend, such as paschimotanasana, but not plow?
What's interesting is that even though the pose takes flexibility (seems pretty obvious), it also take strength (less obvious). Even simpler poses, such as janu sirsasana (head to knee pose shown below) take some strength.
Taking a look at plow, we can break it down by what is required to perform such an asana with integrity and benefit to the body and mind:
Flexibility is needed in the backs of the legs, neck, low back, chest (to keep from collapsing), shoulders, and gluts.
To get the lift and maintain this pose, there must be strength in the shoulders, back, and backs of the legs.
3. Risk Factors
Plow is a more challenging pose and not recommending when you're starting out. Be certain you are comfortable in shoulderstand before attempting plow. Physical risks to watch for are in the neck, shoulders, and low back.
Knowing all of this, if you struggle with a posture, such as plow or janu sirsasana, break it down into where flexibility, strength, and risks for that pose lie. Then use simpler poses to determine where you can use more muscle building, lengthening, or integration. Also, based on past injuries or physical challenges you might face, some poses might do more harm than good; take a look at the risks.