Effects of Dry Needling When Applied to the Infraspinatus Muscle in People With Chronic Shoulder Pain

Study Overview
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Brief Summary
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Up to 77% of patients with chronic shoulder pain have a trigger point (TrP) in the infraspinatus muscle. These TrPs can lead to pain, limitation of activities and reduced quality of life. Dry needling (DN) is gaining popularity as a treatment for TrPs in physiotherapy. However, its clinical effects remain poorly understood mechanistically and its neurophysiological effects little studied. The primary objective of this study is to determine the feasibility of a larger scale study. The secondary objective of this study is to to explore the immediate neurophysiological, biomechanical and clinical effects of DN and sham needling when applied to TrP of the infraspinatus muscle in people with chronic non-traumatic shoulder pain.

Detailed Description
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Methodology In this randomized, double-blind, parallel-group trial, twenty adults with chronic non-traumatic shoulder pain and with a infraspinatus TrP will be recruited according to established criteria. Participants will be randomized into two groups: one group (n = 10) receiving a DN in the infraspinatus TrP and another group (n = 10) receiving a sham needling. Recruitment strategies Recruitment will be done through posters that will be posted on bulletin boards of the Faculty of Medicine and Health Sciences of the University of Sherbrooke and in physiotherapy clinics in the region. The persons interested will be invited to contact the research assistant in charge of the study to verify their eligibility to participate. Data collection procedure The experimental procedure will take place in a laboratory located at the Research Center on Aging in Sherbrooke, Quebec, Canada. Upon arrival, individuals will be greeted by a research assistant. Verification of the presence of TrP in the infraspinatus to confirm eligibility to participate will be carried out by a physiotherapist with more than 20 years of experience in the identification of TrPs and with the application of DN, according to the following procedure: Participants will be asked to lie in a decubitus lateral position on a treatment table and on the asymptomatic side. The upper arm will be supported on a box placed in front of them, so that the muscles can be relaxed, but the arm will be positioned in a and have a slight horizontal adduction to slightly stretch the fibers of the infraspinatus muscle. Manual palpation with flat fingers and perpendicular to the fibers will be used to identify the tight muscle band. Once a tight muscle band has been identified, the physiotherapist will search within this band for a contraction node, namely the TrP. Once she had identified this TrP with a non-toxic black Sharpie pencil, she will validate with the patient that the compression of this TrP reproduces local or referred pain. This pain should correspond to the pain patterns known to the infraspinatus according to Simons and Travell, 1999 and reproduce the pain known by the patient. This pain should be at least a 1/10 intensity on the visual analog scale (VAS). Ineligible participants will receive advices from the physiotherapist as well as a prescription for exercises related to their condition and a list of physiotherapists they can consult. The research assistant will explain the nature of the project to the selected participants, he will make sure that the participants have no contraindications to receive DN and/or for transcranial magnetic stimulation (TMS) examination, and he will obtain written informed consent. Participants will then complete a questionnaire used to collect baseline medical information. Intervention (DN and Sham) DN will be performed by a certified clinician, experienced with the technique. She will explain the purpose of the intervention and she will review the contraindications and precautions for DN to ensure that the procedure is safe. The technique used is recommended by l'Ordre professionnel de la physiothérapie du Québec (OPPQ). The clinician will insert a sterile disposable acupuncture needle, OPTIMED (non-silicone), 40 mm x 0.30 caliber. The direction of the needle will be slightly oblique, directly in the TrP and in the direction of the muscle fibers. The production of a twitch is expected, gliding and rotation of the needle may be performed to produce this effect, if necessary. The needle will be removed after the twitch. The same procedure will be used for the sham group, except that the needle will be inserted at the subcutaneous level, at the depth of the superficial adipous tissues

Official Title
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Neurophysiological, Biomechanical and Clinical Effects of Dry Needling Versus Sham Needling When Applied to the Infraspinatus Muscle in People With Chronic Shoulder Pain: a Randomized Pilot Study

Conditions
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Trigger Point Pain, Myofascial, Chronic Shoulder Pain

Intervention / Treatment
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* Other: Dry needling
* Other: Sham needling (SN)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Unilateral, chronic non-traumatic shoulder pain (VAS ≥ 2/10; >3 months) Localized pain in the shoulder region or referred according to the territory of the infraspinatus (Travell and Simons, 1999) Presence of a palpable nodule inside a tight muscle band reproducing the patient's pain Exclusion Criteria: Cancer or metastasis in organs or tissues above the pelvis (< 5 years) Shoulder capsulitis Shoulder, thorax or mastectomy surgeries Shoulder bone fracture (< 6 months) C4-C5 or C6 radiculopathy Osteoporosis or excessive atrophy of the infraspinous fossa (infraspinatus <10 mm) Body mass index (BMI) > 28 Exclusion (TMS security): Pregnant woman Neurological, psychiatric or epilepsy conditions Implants (e.g. Neurostimulator, pacemaker, cerebral aneurysm clip, screw or plate), metallic foreign body in the eye Head trauma with loss of consciousness

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dry needling (DN)<br>Intramuscular insertion | Other: Dry needling<br>* Intramuscular insertion of an OPTIMED 40mm x 0.3mm acupuncture needle in a trigger point of the infraspinatus muscle<br>|
| Sham Comparator: Sham needling (SN)<br>Intradermal insertion | Other: Sham needling (SN)<br>* Intradermal insertion of an OPTIMED 40mm x 0.3mm acupuncture needle over the infraspinatus region<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recruitment rate | Average number of participants recruited per month | Through study completion, an average of 10 months | 
| Exclusion rate | Number of participants excluded from the study due to eligibility criteria (e.g. too narrow, are they clear) | Through study completion, an average of 10 months | 
| Refusal rate | Number of participants who refused to participate (e.g. fear of needle, fear of transcranial magnetic stimulation) | Through study completion, an average of 10 months | 
| Retention rate | Number of loss at follow-up | Baseline, immediately after and 24 hours post-treatment evaluation | 
| Length of time of the procedure | Average time needed per participant (testing and intervention) | Baseline, immediately after and 24 hours post-treatment evaluation | 
| Safety of the procedure: adverse effects | Listing of any adverse effects | Immediately after intervention to 24 hours post-treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corticospinal excitability of the infraspinatus | Tested with transcranial magnetic stimulation (TMS) connected to a neuronavigation device, characterized by the active motor threshold and expressed in stimulator maximum power percentage | At baseline, immediately after intervention, 24 hours after the intervention | 
| Glenohumeral arthrokinematics | Captured images are taken using ultrasound imaging (GE Logiq-e; linear array 5-12MHz) at 0° and 30° of external rotation. Measurements in cm included: 1) subacromial space (position of the humeral head relative to the acromion); 2) anteroposterior position of the humeral head relative to the glenoid. | At baseline, immediately after intervention, 24 hours after the intervention | 
| Pressure pain perceived | Obtained using an algometer (directly applied on the TrP; average of three measurements taken at 30 sec. interval), characterized by the threshold of discomfort and expressed in kg. | At baseline, immediately after intervention, 24 hours after the intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dry needling, Infraspinatus, Neurophysiological effects