Changes in Surface EMG Activity After Dry Needling Compared to Sham Needling
Condition: Neck Pain, Posterior; Work-Related Condition
MeSH terms: Neck Pain
Study type: Interventional

Summary: 
      An experimental study will be conducted to evaluate the effect of a single dry needling
      session, compared to a sham needling session, on surface EMG activity (signal amplitude and
      frequency) and pain of the upper trapezius muscle, in office workers with trapezius myalgia.
    

Detailed description: 
      Neck-shoulder pain is a prevalent problem in office workers. These complaints are often
      related to myofascial dysfunctions of neck and shoulder muscles, in which the upper trapezius
      is a vulnerable victim due to prolonged static postures, repetitive upper limb movements and
      stress, often present during office and computer work. Myofascial dysfunction of the upper
      trapezius muscle is often referred to as "trapezius myalgia (TM)". Trapezius myalgia is
      clinically diagnosed with the presence of pain, palpable stiffness and tenderness of the
      upper part of the trapezius muscle. Several studies show that myofascial trigger points
      (MTrPs) play an important role in the development and maintenance of myofascial pain and
      trapezius myalgia. Myofascial trigger points are defined as hyperirritable nodules in a
      contracture of skeletal muscle fibers, which can cause pain symptoms, motor symptoms as well
      as autonomic symptoms.

      The pathophysiology of MTrPs is still unclear but several hypotheses exist. The most
      plausible explanation is that, due to sustained postures or repetitive low-level tasks, a
      sustained irritation of motor end plates with an excessive release of acetylcholine arises.
      This may lead to a persistent sarcomere contraction, leading to an impaired local blood
      circulation, a reduced tissue oxygenation and energy depletion, the sensitisation of
      nociceptors and thus the development of pain.

      Dry needling (DN) is a myofascial treatment technique, which has been gaining interest in
      recent years. During dry needling, a thin, solid filiform needle is inserted directly into
      the MTrP. During this treatment, local twitch responses can be elicited. These are
      involuntary contractions of muscle fibers, leading to muscle relaxation, an increased local
      blood flow, recovery of the muscle metabolism and thus a reduction of pain and stiffness.

      In this experimental study, 60 office workers with trapezius myalgia are recruited from
      several work places with predominantly computer based tasks. Participants are required to
      perform at least 20 hours of computer work a week, and this since at least one year.
      Participants are included based on online questionnaires, a clinical examination of neck and
      shoulder, and the identification of a MTrP in the upper trapezius muscle. All participants
      will receive information and have to sign an informed consent form.

      Participants will be subjected to baseline assessment, which involves measurements of the
      surface EMG activity (during rest ) and pain scores. Then, subjects will be required to
      perform a computer task during 20 minutes, surface EMG activity will be measured every 5
      minutes. After this computer task, surface EMG activity (during rest ) and pain scores will
      be measured again. Then, participants will be randomly allocated to either a dry needling
      group or a sham needling group. The dry needling group will receive a dry needling treatment
      at the identified trigger point location of the upper trapezius, whereas the sham needling
      group will receive an intervention in which the needle only penetrates the skin but not the
      fascia and muscle tissue. After the treatment, surface EMG activity and pain scores will be
      measured again immediately after, 15 minutes and 30 minutes after completion of the
      intervention. Thereafter, pain scores will be asked daily, during 7 days after completion of
      the study.
    

Intervention name(s): Dry needling; Sham needling
Intervention type(s): Other; Other
Intervention description(s): Dry needling (DN) is a myofascial treatment technique, in which a thin, solid filiform needle is inserted directly into the MTrP. During dry needling, local twitch responses (LTR) can be elicited. These are involuntary contractions of muscle fibers, leading to muscle relaxation, an increase in blood flow,recovery of the muscle metabolism and thus a reduction of pain and stiffness.; During sham needling, a solid, filiform needle is inserted in the skin surface at the trigger point location, without penetrating the fascia and muscle tissue.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Other
Keywords: Dry needling; Sham needling; Office workers; Myofascial pain; Surface electromyography