Effects of ergomotor intervention on motor control in the neck and shoulder region during functional movements in people with work-related neck shoulder disorders

Background. Work-related neck and shoulder disorders are common health problems affecting workers in many different occupations in office and industrial settings. A new intervention approach that combines ergonomics intervention and motor control training has been investigated in a randomized controlled trial with a one year follow up. The “ergomotor” approach consists of a 12-week intervention program that integrates the ergonomic interventions with the clinical approach of motor-control training. Participants allocated in the control group received 12 weeks of conventional physiotherapy. Methods. 50 subjects were recruited in each of the ergomotor (EM) and control (CO) groups. Participants were from different occupations who reported more than three months’ history of work-related neck and shoulder pain. Each participant underwent a detailed biomechanical assessment involving surface electromyography (EMG) and 3D kinematics measurement of the neck and shoulder region at both pre- and post-intervention. Participants were required to perform three repetitions of lifting a weighted object (2 kg) in a forward-backward (F-B) functional task. Results. Results of preliminary analysis with seven subjects in each group showed some apparent changes in muscle activity of the upper trapezius (UT) and lower trapezius (LT) during functional tasks. For example, in the FB test, UT showed a reduction from 46.3% of the EMG recorded in reference voluntary contraction (RVC) to 35.3% RVC in the EM Group, whereas the CO group decreased by about 5% from 51.4%. When this task was repeated with scapular retraction, the EM Group showed even greater reduction in UT activity (from 45.5% to 32.7%) and corresponding increase in LT activity (from 70.6% to 98.7%) at the post-intervention assessment. Discussion. The results suggest an improved motor-control strategy in the functional movement pattern of workers who received ergomotor intervention. This effect can contribute to more sustainable reductions in work-related musculoskeletal symptoms in the long term.