Traditionally, yoga practitioners are recommended to start meditation after they have achieved some sort of physical fitness through asana (i.e. the poses) and pranayama (i.e. breathing) practice. This hierarchical method prepares the body (the muscles, joints and lungs) to sit without aches and pains for extended periods during meditation.
One of the main reasons that lotus pose i.e. padmasana is the recommended pose to meditate in is that the external rotation of the hips allows the pelvic girdle to tilt in such an angle that the spinal column inserts in the joint (sacrum) in its anatomically neutral angle, that is in close angle to that of the standing position. Sitting longer period in any other position puts more pressure on this joint. That is why it is recommended that office workers or those who sit at length take breaks every 30mins or so and move this area and allow better blood flow. However, the hip rotation that padmasana requires is very deep and usually achieved after some years of practice. Of course, in the mean time the back muscles that erect and keep the spinal column so gain enough strenght to perform their part.
Given all this, my suggestion to those who want to start meditating but feel pain in the lower back, knees, and shoulders would be the following.
Take 5-10 minutes everyday to do the following:
- Take breaks from work and stand up and move the hip joints for a couple of minutes.
- Forward folds (standing or seated) help a lot to stretch the back muscles and the hamstrings, which relieve some tension.
- Simple standing or reclined spinal twists will help the spine to reset.
- Try a comfortable variation of pavanamuktasana or ananda balasana.
Before, during or after meditation:
As you may have noticed, sitting with a curled back squeezes the lungs -not good for pranayama- and will cause more spinal pain after meditation. So, use props to come into the most comfortable position. You can sit against the wall, use support under knees and feet. Start with short periods and allow your body to adjust to the new pose and practice. And listen to your body and muscles.
Calmly observe and ignore what you can or change position and make a note of that discomfort to modify your starting position accordingly. It takes a while to find the right position to meditate. Keep experimenting.