Stress management as an adjunct to physical therapy for chronic neck pain

Abstract

Background and purpose: Chronic neck pain is prevalent in the workplace. Research suggests that psychosocial stress may contribute to the development of neck pain by causing excessive or prolonged muscle activity in some individuals. The purpose of this case report is to describe the rationale, development, and implementation of stress management as an adjunct to standard physical therapist management of chronic neck pain in a female office worker who responded to psychosocial stress with elevated muscle activity prior to treatment.

Case description: A 44-year-old female office employee with an 8-year history of chronic neck pain participated in this case report. The patient was selected from a group of research participants who demonstrated elevated electromyographic (EMG) activity of the trapezius muscle in response to simulated occupational stressors. The multidisciplinary intervention consisted of 8 physical therapy sessions, supplemented by 8 stress management sessions that included EMG biofeedback and psychotherapy to facilitate muscle relaxation.

Outcomes: Neck disability decreased by 50%, trait anxiety decreased by 21%, and the duration of trapezius muscle rest in the workplace increased by 56% immediately after the 8-week intervention. These improvements were maintained 6 months after treatment, and the patient reported a complete absence of neck disability at the 2-year follow-up assessment.

Discussion: A sustained reduction in neck disability was observed for a patient with chronic neck pain after participating in a multidisciplinary intervention that combined physical therapy and stress management approaches to facilitate muscle relaxation in the workplace. Future clinical trials are needed to assess whether stress management is a useful adjunct therapy for patients with chronic neck pain who show elevated muscle activity in response to psychosocial stress.

Figure 1.

Stress-evoked muscle activity during simulated occupational stressors. Raw electromyographic recordings of the dominant upper trapezius muscle are shown for computer mousing and typing tasks performed under low stress (gray) and high stress (black) conditions. During the low stress condition, the patient was told that the trial was just for practice and that her performance would not be monitored. The high stress condition was administered by an authoritative tester and was performed with time and accuracy constraints, video surveillance, verbal feedback to correct mistakes, and a monetary incentive for high scores. Self-reported state anxiety increased from the low stress to the high stress condition (Speilberger State-Trait Anxiety Inventory state anxiety [STAI-S] score: low=24 points; high=33 points), whereas the magnitude of neck pain changed minimally across stress conditions (10-cm visual analog scale: low=3.8 cm; high=3.9 cm). Despite performing identical mousing and typing tasks across the 2 stress conditions, trapezius muscle activity increased markedly during exposure to the psychosocial stressor.

Figure 2.

Representative recording of trapezius muscle activity during biofeedback intervention. Activity of the dominant upper trapezius muscle was monitored with surface electromyography (EMG) while the patient performed a Stroop mousing task (Tab. 2, session 3). The feedback threshold (dashed gray line) initially was set for this particular task at 80% of the mean muscle activity recorded during a 60-second baseline trial (left), which the patient performed using her preferred motor strategy without biofeedback. During the subsequent biofeedback trial (right), auditory cues (gray circles) were provided to remind the patient to relax whenever the amplitude of the EMG signal exceeded the feedback threshold in more than 20% of the samples recorded during the preceding 20-second monitoring window. Verbal and manual cues from the physical therapist also were provided to help the patient achieve and maintain a relaxed posture. After the patient failed to relax her muscles in response to auditory cues during the first half of the mousing trial, verbal instructions (arrow) were provided to “relax your shoulders and lean back against the chair.” This instruction allowed the patient to perform the required task while keeping her trapezius muscle relaxed for the remainder of the trial. RMS=root mean square.

Figure 3.

Outcomes measured before and up to 6 months after treatment. Trait anxiety (A), neck disability (B), static muscle activity (C), and muscular rest (D) were assessed before (Pre), immediately after (Post), and 3 months (3 mo-Post) and 6 months (6 mo-Post) after the 8-week multidisciplinary intervention. Dashed gray lines indicate published cutoff scores for generalized trait anxiety on the Speilberger Trait Anxiety Inventory (STAI-T; A) and mild (5–15 points) to moderate (16–25 points) disability categories on the Neck Disability Index (NDI; B). The patient reported clinically significant improvements in trait anxiety and neck disability immediately after treatment that were maintained up to 6 months. Long-term improvements in neck disability were reported up to 2 years after treatment (NDI score=0 points; data not shown). The pattern of changes in static muscle activity and muscular rest recorded in the dominant upper trapezius muscle across time was similar to that observed for trait anxiety and neck disability, where lower values of static muscle activity and higher values of muscular rest indicate an overall reduction of muscle activity in the workplace following treatment. Error bars represent standard deviation of measurements obtained during 2 days of workplace monitoring. RMS=root mean square.

Figure 4.

Habitual patterns of trapezius muscle activity in the workplace. Representative activity of the dominant upper trapezius muscle is shown for 5-hour recordings obtained during a typical workday before (A) and immediately after (B) the 8-week multidisciplinary intervention. The root mean square (RMS) amplitude of the electromyographic signal was normalized to a submaximal reference voluntary contraction and plotted as a function of time. Habitual activity of the trapezius muscle during daily work activities was visibly reduced following the intervention.