The effects of two interventions on persistent pain:: A multiple single-case study among sign language interpreters

The goals of the present study were: (1) to explore the effects of two interventions (B: stress management and C: work style) among sign language interpreters (SLIs), using a single-case cross-over design; and (2) to document the feasibility of using such a repeated measures design in exploring work intervention impact. Seven participants reporting persistent pain during the baseline measurements were followed up every week using a questionnaire (psychological stress, musculoskeletal symptoms) and direct measurements (electromyography and goniometry) throughout the entire study. Interviews with the participants, management and union representatives, and questionnaires to the teachers and deaf students were used to assess feasibility. After the first baseline was established for all participants, three of them received intervention B followed by a second baseline and intervention C. The four other participants first received intervention C, followed by the second baseline and intervention B. Both interventions demonstrated a potential to reduce pain. For three of the four participants showing a reduction in pain, it was accompanied by a reduction in either the perceived stress or mechanical exposure, or both. It cannot be concluded that one intervention is better than the other. However, the fact that some individuals respond to one intervention or the other reveals that implementing both interventions would have the best chance for success in preventing disability among workers reporting persistent pain. Performing such a repeated measures design on a weekly basis was challenging for the participants, especially for instrumented measures. This type of design might however prove to be useful when exploring new interventions, especially if direct measurements Lire not of interest.