Yoga for common ailments - stiff hips

“For many of us in the West, and increasingly in the East, hip joints are stiff and liable to arthritis and other degenerative conditions due to lack of use and by sitting for long hours on poorly designed furniture. The hips are ball and socket joints. Normally , however, we use them as simple hinge joints, ie in a forward and backward direction only. As the old adage states, ‘what you don’t use, you lose’. Hip joint replacements are amongst the most commonly performed operations in Western countries. While they are often very successful and can give a whole new lease of life, any operation has its dangers and artificial joints do not last forever. Any subsequent replacement carries a far greater risk of failure as well as the added risks of the operation itself, particularly when they mostly occur amongst the elderly.
   The exercises below are designed to help keep the ball and socket joints in good working order by encouraging the natural oiling mechanism of the joint, making sure that maximum flexibility is maintained for as long as possible. It doesn’t matter if you can’t manage the full position, just try what is possible within your limitations, bearing in mind that improvements may be experienced with practice and patience.
   The sitting posture forms the base of many Yoga asanas, it is also very helpful to practise these warm up exercises before undertaking Pranayama and meditation, to enable you to sit comfortably for extended periods.

Precautions
• Do NOT attempt these exercises if you already have had a hip replacement.
• If you have arthritis or other medical condition which restricts movement,
  ALWAYS consult with your doctor first...”

The article continues to list four exercise sequences; rocking the baby, butterfly stretch - Baddhakonasana; tortoise stretch - Kurmasana; and hugging the knees to the chest. It also lists modifications and more advanced poses for some of the exercises.