Fig. 1.

Time line of the treatment protocol. The treatment started with the traction therapy whether the IDD or the SHAM protocol. This consisted of 20 half-hour sessions during the first 6 weeks of the treatment (green line). Two weeks after initiation started the standard therapeutic care (graded activity) and lasted 12 weeks (blue line). The graded activity program consisted of 1 h of training for 2 days per week