Changes in cognitive-behavioral factors and muscle activation patterns after interventions for work-related neck-shoulder complaints: relations with discomfort and disability.
OBJECTIVE
Knowledge regarding the working mechanism of an intervention is essential for obtaining a better understanding of the intervention and contributes to optimize its outcome. This study aimed at investigating whether changes in cognitive-behavioral factors and muscle activation patterns after myofeedback training and ergonomic counseling were associated with outcome, in subjects with work-related musculoskeletal neck-shoulder complaints.


METHODS
Seventy-nine symptomatic subjects received either myofeedback with ergonomic counseling (Mfb/EC) or ergonomic counseling alone (EC). Outcome measures discomfort and disability, and process factors catastrophizing, pain control, fear-avoidance beliefs, and muscle activation patterns were assessed at baseline, after the interventions (T0), and at 3 months follow-up (T3). Mixed modeling techniques were used for analysis.


RESULTS
Outcome in terms of discomfort and disability was generally comparable between both interventions. Catastrophizing was significantly reduced and fear-avoidance beliefs about work slightly increased after the interventions, but no consistent changes in muscle activation patterns were observed. Changes in discomfort were especially associated with changes in catastrophizing at T0 and T3, but R(2) was low (<0.14). Reduced catastrophizing at T0 and T3, and also reduced fear-avoidance beliefs about work at T3, were related to reduced disability (R(2) between 0.30 and 0.40). No differences between the two intervention groups were observed.


CONCLUSIONS
Intervention effects were generally non-specific and findings suggested that cognitive-behavioral factors underlie the outcome of these interventions rather than changes in muscle activation patterns. Emphasizing these factors during therapy may increase the beneficial outcome of occupational interventions.
Voerman
Gerlienke E
GE
Roessingh Research and Development, 7500 AH, Enschede, The Netherlands. g.voerman@rrd.nl
Sandsjö
Leif
L
Vollenbroek-Hutten
Miriam M R
MM
Larsman
Pernilla
P
Kadefors
Roland
R
Hermens
Hermie J
HJ
D000223:Adaptation, Psychological; D000328:Adult; D003071:Cognition; D006233:Persons with Disabilities; D004576:Electromyography; D005260:Female; D015438:Health Behavior; D006305:Health Status Indicators; D006801:Humans; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000503:physiopathology / Q000523:psychology* / Q000628:therapy; D009333:Neck / Q000503:physiopathology*; D019838:Neck Injuries / Q000503:physiopathology / Q000628:therapy*; D010146:Pain / Q000503:physiopathology / Q000523:psychology*; D059408:Pain Management; D010147:Pain Measurement; D011594:Psychometrics; D020069:Shoulder Pain / Q000503:physiopathology / Q000628:therapy*; D011795:Surveys and Questionnaires