If you think there's no way to get your mind off of discomfort in your body, try this practice to shift how you experience it.
Let your body settle into a posture that is relaxed and at ease. If you are sitting, try to keep your back and neck upright. If your body is very distressed, lie down comfortably on your back with a commitment to being fully awake and present.
Let your eyes close gently.
For a few moments just be aware of your entire body. Consciously soften any areas of tightness or tension. Move a gentle, curious attention slowly over your face, jaw, shoulders, and hands, allowing them to soften and relax.
Be aware of all the places your body contacts the floor, cushion, or chair, sensing the warmth or subtle pressure within those places of contact.
Expand your attention, becoming aware of your entire body resting in as much ease as possible. Bring a wholehearted attention to your body. Sense the touch of the air on your skin and the touch of your clothes on your body. Let your awareness include your heart beating and the rising and falling of your chest and abdomen with your breathing. Sense too the multitude of different sensations happening within your body—tingling, warmth, movement, pleasant and unpleasant sensations...
Within the range of the different experiences, notice which sensations are most predominant, which area of your body stands out through the intensity of the sensation. This is the area asking for your attention.
Focus as fully as possible on that area of your body, tracing the edges of the discomfort with your attention, as if you were tracing the edges of a feature on a map.
Connect very directly with the sensations. Try to stay closely connected with the actual experience of the sensations in your body.
Notice where the edges of the pain or discomfort fade on the edges of the map and where different sensations are present, sensations of warmth, pressure, or movement.
Let your attention rest in those areas for some moments, noticing the sensations that are pleasant or neutral.
Notice the sensations present in your hands, the soles of your feet, all the parts of your body that are not in the map of pain.
Bring your attention back into the map and focus your attention very directly on where the sensations are most acute. Notice that there may be points of intensity surrounded by areas of tension or discomfort.
Move your attention into the center of the pain and notice its texture, whether tight, piercing, aching, or stabbing. Ask, "What is this?"
If you notice that your attention begins to become tight, aversive, or fearful, again move it to a part of your body that is outside the map of pain. Rest and focus your attention there once more, renewing your calmness and balance. Then return again to the points of pain within the map.
There may be a number of these points. Carefully move your attention from one to another, gently exploring each one. Notice what changes may be happening within those points of discomfort, how the sensations may be changing in texture or arising and passing.
Be patient with the exploration, not demanding that the pain disappear, but being simply willing to explore the truth of that sensation.
Whenever your attention becomes tight or aversive as you focus on areas of acute sensation, it is a clue to go outside the map of pain once more to focus on an area of your body that is relaxed and at ease. You are learning to visit pain, explore it, see it as it is, but always giving yourself permission to leave it.
End your meditation by returning once more to an awareness of your whole body, alert to the spectrum of sensation that comprises the life of your body.
Rest in that spacious awareness for some moments before opening your eyes and slowly coming out of your meditative posture.
Also see16 Poses to Ease Back Pain