Ergonomic Puzzle

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Across
  1. 6. Not a promotion, but same direction
  2. 7. Lots of effort
  3. 8. Not again, and again, and again
  4. 10. Shaking things up
  5. 11. Rearrange to suit your needs
  6. 12. Your surroundings
Down
  1. 1. Tough tissue
  2. 2. No gas fill ups at this one
  3. 3. You must keep good _ when sitting or standing
  4. 4. This supports you
  5. 5. Changing position
  6. 9. Below your knee