Musculoskeletal disorders are frequent among office workers especially in the neck/shoulder area.

The hypothesis is, that specific strength training of the neck/shoulder muscles will alleviate the pain.

The two sub-hypotheses are

1. Alleviation of pain is independent of training frequency
2. Alleviation of pain is higher following supervised training vs training with initial instruction only

Recent studies have shown a positive effect of work site physical exercise intervention, however, there is a lack of evidence regarding: 1) extend of instruction and supervision, and 2) frequency of training session during the wek.

Questionnaires will be send to around 2000 office workers inviting them to participate in work site training for 1 hr per week for 20 weeks. Those accepting the invitation will be randomized into 5 different groups:

1. training 1 hr one time per week supervized 50% of the time
2. training 3 x 20 min per week supervised 50 % of the time
3. training 3 x 20 min per week supervised only initially with careful instructions
4. training 10 x 6 min per week supervised 50 % of the time
5. no training serving as reference control group At termination of the training period there will be a follow-up questionnaire survey

Inclusion Criteria:

• office workers
• employed

Exclusion Criteria:

• physically heavy work
• trauma
• leif threatening disease, e.g. cancer,
• pregnancy