The ReTra system worn by clients receiving the MYOTEL intervention. Left: Harness with incorporated dry surface electrodes. Right: Signal processing, storage, and vibration unit
The ReTra consists of (1) a harness with four incorporated surface electrodes that continuously measure surface electromyography (sEMG) from the trapezius muscle, (2) a portable unit that stores signals and processes functionality, and (3) a personal digital assistant (PDA) to provide continuous feedback to the client on the level of the taut muscle in the form of the EMG signals.
Client data are sent from the PDA (e.g., via GPRS) to a secure server. This is accessible to authorized health-care professionals via a web portal, and is thus available all the time regardless of where the OT is. The system enables the OT to interpret the data both in real time and historically, permitting e-consultation.
The MYOTEL Intervention Program
As well as providing bio-data, clients keep a daily diary of their performed activities and the pain they experienced. At least once a week, but more often if needed, the OT and the client consult, face to face or by telephone.
Material for this consultation is the OT’s study of the EMG data and the client’s diary. The OT identifies the problems seen in muscle patterns (relaxation and activation). Based on these data, together with the diary activities, events when the client experiences low levels of relative rest times (RRT) are identified.
Subsequently, the OT and client together seek solutions, and the client is taught appropriate skills and techniques to develop better functioning.
The week’s progress is discussed: how clients learn to identify aspects relevant to their pain, plus the very important aspect of learning self-management. The consultation ends with new tasks and an appointment for the next week.
Intervention normally ends after 4 weeks with a face-to-face visit. The MYOTEL program is presented in Fig. 47.2.
Clients wear the harness with the surface electrodes (Fig. 47.1) during their performance of daily activities for 4 weeks. This gives very intensive and continuous feedback from tasks performed in their environment (Voerman et al. 2007a).
The program enables quick adaptation of the client’s behavior and shows the long-term effects of the intervention.
Hermens and Hutten (2002) investigated the processes underlying the feedback mechanisms andfound that changes in the discomfort factor were especially associated with changes in catastrophic thoughts; reduction in disabilities was related to decreased catastrophic thoughts about fear and avoidance of working. However, the percentage of explained variance was no more than 30–40 %.
The myofeedback intervention has been evaluated in a number of studies (Hermens and Hutten 2002; Huis in’t Veld et al. 2008; Voerman et al. 2006, 2007b). The studies show that over the 4 weeks of the intervention, the clients wore the equipment for at least 4 h a day, 5 days per week. The results of a prognostic cohort study in 21 clients with work-related pain show that about 60 % improved their pain/discomfort scores directly after myofeedback, and these were practically unaltered at 4-week follow-up. A remarkable finding is that 35–40 % of the clients show a further improvement on pain/discomfort when the myofeedback had already ended (Hermens and Hutten 2002). A prognostic cohort study in 14 clients with chronic whiplash disorders showed significant effects on pain and disabilities: 55 % of the clients showed a clinically relevant reduction of pain and 36 % of disabilities (Voerman et al. 2006). In a randomized clinical trial comparing myofeedback (n = 41) with ergonomic consultation (n = 38) for clients with work-related neck–shoulder pain in the Netherlands and Sweden, 50 % of the clients experienced a clinically relevant reduction in pain and disability, which persisted at a 6-month follow-up (Voerman et al. 2007b). Myofeedback with remote data gathering and e-consultation is being tested in a cross-sectional study in 15 clients and 17 professionals to obtain insight into end users’ attitudes and self-efficacy regarding remote myofeedback intervention. Results showed that both clients and professionals expect the remote myofeedback intervention to be feasible. Attitudes were positive in 66 % of the clients and 46 % of the professionals. In addition, the majority of clients and professionals considered their self-efficacy sufficient for remote myofeedback intervention, and they expected at least the same effects as from the traditional intervention (Huis in’t Veld et al. 2007). A subsequent prognostic cohort study in ten women with work-related pain showed that RRP is technically feasible. Eighty percent of clients report;ed a reduction in pain intensity and disability directly after RRP (Huis in’t Veld et al. 2008). The Swedish part of the European MYOTEL project (www.myotel.eu) was evaluated among 65 women with neck and shoulder pain. During three mounts, 33 women took part in the muscle relaxation training during their work performances. Evaluation showed no significant improvement in pain status among the “MYOTEL” women compared to those who participated in conventional care, however, with favors for comfort and time saving (Sandsjö et al. 2010 2).
The most common interventions aimed at chronic pain disorders are the multidisciplinary team approach, of which the RRP program as outlined as above is one. However, even with an indication tree for the decision on whether to intervene, the RRP is not effective for all clients. One explanation may be that not every client is inactive due to back pain and fear, and lowered physical capacity with, consequently, overloading. In Hasenbring et al. (2001), model and in clinical practice, some clients lack fear but ignore the pain. These clients are probably much more helped by learning how to balance their activity patterns during the day than by physical reconditioning. Here, the present intervention including goal setting may probably be more effective. Another explanation why the intervention does not suit all clients might be that the skills learned in the rehabilitation program are too specific, occasioning problems with their generalization to daily life. This led to the notion that providing intervention in the client’s daily environment by using ambulant monitoring and feedback systems could be effective. The telemedicine concept manifested in the MYOTEL service seems to be a good example. Results of the first evaluations indicate that this service is at least as effective as traditional interventions. In clients with chronic back pain, such an intervention should focus on activity levels. An intervention with focus on temporal adaptation, in which the feedback is directed toward normalization of the disturbed activity pattern, might be effective.