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Alterations in Central Control of Shoulder Muscles in Office Workers With Non-specific Chronic Neck Pain

Not Applicable
Completed
Conditions
Non-specific Chronic Neck Pain
Office Workers
Transcranial Magnetic Stimulation
Neuromuscular Control
Interventions
Other: 30-minute computer typing task
Other: 30-minute rest
Registration Number
NCT05000177
Lead Sponsor
National Yang Ming Chiao Tung University
Brief Summary

Non-specific chronic neck pain (NCNP) is commonly seen in office workers. Individuals with NCNP not only demonstrate impaired neck movement control and muscle activation, but also show abnormal scapular kinematics and muscle activation timing. Office workers with NCNP also show higher activity of upper trapezius during computer typing and have difficulty relaxing upper trapezius after typing. These changes related to scapula may increase strain over neck. In addition to the altered neuromuscular control, recent studies found neuroplasticity changes in the central nervous system on patients of chronic musculoskeletal disorders. Therefore, few studies found shifts and alterations of motor cortex representation of neck muscles in individuals with NCNP, which was correlated with delayed muscle activation of deep neck flexors muscle in functional activities. However, no studies have explored that whether this corticospinal adaptation also happens over scapular muscles, especially after a computer typing task. The objectives of this proposal are to investigate the differences in corticospinal and neuromuscular control of shoulder complex between office workers with and without NCNP. Thirty-five individuals with NCNP and 35 healthy controls will be recruited. Twenty young healthy subjects will be also recruited for a pilot study to test the reliability of all the measures. Scapular kinematics and muscle activation will be tested during arm elevation. Corticospinal parameters of trapezius and serratus anterior will be tested with transcranial magnetic stimulation (TMS), including active motor threshold, motor evoked potential, cortical silent period, short interval intracortical facilitation, short interval intracortical inhibition and cortical mapping. Corticospinal parameters, except cortical mapping, will be measured again after a 30-minute computer typing task. Scapular muscle activation will be also recorded during the typing task.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
51
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Experimental group: Non-specific chronic neck pain group30-minute computer typing taskSubjects with non-specific chronic neck pain will be included to perform 30-minute computer typing task and assess neurophysiological measurements of scapular muscles, scapular kinematics and muscle activation.
Pilot study: Healthy subjects group30-minute restHealthy subjects will be included to test reliability of single-pulse and paired-pulse TMS, including its associated neurophysiological measurements, and also to test reliability of Liberty electromagnetic tracing system and surface electromyography. Subjects in this group will received the same assessment as the NCNP group.
Control group: Healthy subjects group30-minute computer typing taskHealthy subjects will be included to compare the differences in neurophysiological measurements of scapular muscles, scapular kinematics and muscle activation between healthy subjects and subjects with non-specific chronic neck pain. Subjects in this group will received the same assessment as the NCNP group.
Primary Outcome Measures
NameTimeMethod
Neurophysiological measures - Active motor thresholdChange from baseline AMT after 30-minute computer typing task or 30-minute rest

Active motor threshold (AMT) will be described with the percentage (%) of maximum stimulator output (MSO).

Neurophysiological measures - Motor evoked potentialChange from baseline MEP after 30-minute computer typing task or 30-minute rest

Motor evoked potential (MEP) will be described with millivolt (mV).

Neurophysiological measures - Cortical silent periodChange from baseline CSP after 30-minute computer typing task or 30-minute rest

Cortical silent period (CSP) will be measured with millisecond (ms)

Neurophysiological measures - Center of gravity of cortical mappingChange from baseline center of gravity of cortical mapping of cortical mapping after 30-minute rest (pilot subjects)

Center of gravity of cortical mapping will be described in a x-y coordinate system (mm).

Neurophysiological measures - Volume of cortical mappingChange from baseline volume of cortical mapping after 30-minute rest (pilot subjects)

Volume of cortical mapping will be calculated with multiplying summation of motor evoke potentials on the map (mV) by the area of the map (mm2) with the unit of mV\*mm2

Neurophysiological measures - Short interval cortical facilitationChange from baseline SICF after 30-minute computer typing task or 30-minute rest

Short interval cortical facilitation (SICF) will be defined as percentage (%) of conditioning responses vs testing responses while the inter-stimulus interval is above 5 ms

Neurophysiological measures - Area of cortical mappingChange from baseline area of cortical mapping after 30-minute rest (pilot subjects)

Area of cortical mapping will be described with square millimeter (mm2)

Neurophysiological measures - Short interval cortical inhibitionChange from baseline SICI after 30-minute computer typing task or 30-minute rest

Short interval cortical inhibition (SICI) will be defined as percentage (%) of conditioning responses vs testing responses while the inter-stimulus interval is below 5 ms

Secondary Outcome Measures
NameTimeMethod
Scapular kinematics during arm elevationChange from baseline scapular kinematics after 30-minute rest (pilot subjects)

Scapular kinematics, including anterior/posterior tilt, upward/downward rotation, and internal/external rotation in scapula plane elevation at 30°, 60°, 90°, and 120°, and will be described with degree (°).

Scapular muscles activation during performing the computer taskChange from baseline during the 30-minute computer typing task at 5, 10, 15, 20, 25, 30 minutes of the task

The root mean square of electromyography (EMG) data of the upper trapezius, lower trapezius, and serratus anterior will be calculated with a window of 10 seconds and will be normalized by the maximum voluntary contraction amplitude (percentage of maximal voluntary contraction, %).

Scapular muscles activation during arm elevationChange from baseline scapular muscles activation after 30-minute rest (pilot subjects)

The root mean square of electromyography (EMG) data of the upper trapezius, lower trapezius, and serratus anterior will be normalized by the maximum voluntary contraction amplitude (percentage of maximal voluntary contraction, %) and calculated over three 30° increments of motion during arm elevation from 30° to 120°, including 30° - 60°, 60° - 90°, and 90° - 120°.

Craniovertebral angleChange from baseline craniovertebral angle after 30-minute rest (pilot subjects)

Craniovertebral angle will be measured as the included angle between the tragus, C7 spinous process and the horizontal line and will be described with degree (°)

Scapular kinematics during performing the computer taskChange from baseline during the 30-minute computer typing task at 5, 10, 15, 20, 25, 30 minutes of the task

The average of scapular kinematics, including anterior/posterior tilt, upward/downward rotation, and internal/external rotation will be calculated with a window of 10 seconds and will be described with degree (°).

Trial Locations

Locations (1)

National Yang-Ming University

🇨🇳

Taipei, Taiwan

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