Clinical Outcomes, Viscoelastic Properties and Central Pain Mechanisms After Eccentric Training in Neck/Shoulder Pain

Clinical Outcomes, Muscle Stiffness and Creep, and Central Pain Mechanisms Are Improved After Eccentric Training in Female Computer Users With Chronic Neck/Shoulder Pain

Objectives: The aims are to 1) evaluate the clinical impact of eccentric training in female computer users with chronic NSP, 2) compare pressure hyperalgesia, temporal summation of pain (TSP), and conditioned pain modulation (CPM) in female office workers with and without NSP, and 3) assess changes in central pain responses after training.

Methods: In part A, twenty office workers with NSP will be compared with 20 healthy controls. In part B, the NSP group will undergo a 5-week eccentric training program. Participants will report their pain intensity, and complete the Neck Disability Index, and the Disabilities of the Arm, Shoulder and Hand questionnaire. Pressure pain thresholds (PPTs) will be assessed over the neck and forearm. Cuff algometry will identify pain detection (PDT) and tolerance thresholds (PTT). TSP will be evaluated by visual analogue scale pain scores during 10 repetitive cuff stimulations. CPM will be calculated as the difference in PDT with and without a conditioning painful stimulus. Outcomes will be measured at baseline and post-intervention.

Inclusion Criteria:

• Neck / shoulder pain has to last more than 12 weeks', with an average score higher than 2 on a 11-point Numeric Pain Rating Scale within the last 24 hours and during the week before data collection.
• All subjects will have to work for a minimum of four hours per day using a computer, should speak and understand English, and could not be involved in regular strength training of the neck/upper extremities

Exclusion Criteria:

• previous whiplash; a history of neurological or mental illnesses; consumption of pain killers within the last 24 hours; drug addiction, defined as the use of cannabis, opioids or other drugs; fibromyalgia; previous cervical spine or upper limb surgery; carpal tunnel syndrome; concomitant injury or pain from the lumbar spine; and heart diseases or hypertension.