Individual treatment expectations predict clinical outcome after lumbar injections against low back pain by Müller-Schrader, M, Heinzle, J, Müller, A, Lanz, C, Häussler, O, Sutter, M, Eggspühler, A, Mare, S, Toussaint, B, Pereira, I, Petzschner, FH, Wiech, K, Barth, J, Witt, CM, Stephan, KE, Manjaly, Z-M