Short Interventions to Prevent Trapezius Muscle Fatigue in Computer Work

NCT03863340 | Completed

• 1 other identifier: 32003B_160207
• Study Type: interventional
• Target: 30
• Locations: 0 countries
• Sites: N/A

Brief Summary

This study is expected to demonstrate that during experimental days of seated computer work sustained and focalized low-level muscle activity contributes to the development of long-lasting fatigue effects (and thus possible disorder). On days with and without frequent interruptions, signs of fatigue and the activity pattern of the trapeze muscle are registered and compared using electromyographic registrations of the trapezius muscle.

Conditions

Muscle Fatigue; Trapezius Muscle Strain

Keywords

muscle fatigue; work-related disorders; trapezius myalgia; sustained working task; high-density EMG

Outcome Measures

Primary Outcomes (4)

• EMG profile recorded by a single bipolar electrode: Rest-time

  Rest-time (percentage of time below 5% of the standard activity level). The percentage of registration time without any rest time is called sustained low level muscle activity.

  Continuously from the beginning to 370 min (end) of the simulated working activity of both the control and intervention day

• Spatio-temporal distribution of EMG activity: Area of muscle activity

  The spatio-temporal distribution of EMG activity is detected by a 2D array of electrodes (64 channels) and the following outcomes are determined: Area of muscle active region (n. of channels)

  Continuously from the beginning to 370 min (end) of the simulated working activity of both the control and intervention day

• Muscle fatigue: Change of muscle twitch

  3-D muscle twitch acceleration pattern measured at the acromion

  Change between 30 min before the beginning of the simulated working activity and 30 min after the end of the simulated working activity of both the control and intervention day

• Muscle fatigue: Change of dynamic force control accuracy

  Force control accuracy (mean squared error between the produced force (N) and the target force (N)) in an isometric dynamic tracking task

  Change between 30 min before the beginning of the simulated working activity and 30 min after the end of the simulated working activity of both the control and intervention day

Secondary Outcomes (5)

• EMG profile recorded by a single bipolar electrode: Static activity

  Continuously from the beginning to 370 min (end) of the simulated working activity of both the control and intervention day

• Spatio-temporal distribution of EMG activity: Magnitude of activity

  Continuously from the beginning to 370 min (end) of the simulated working activity of both the control and intervention day

• Spatio-temporal distribution of EMG activity: Number of active epochs

  Continuously from the beginning to 370 min (end) of the simulated working activity of both the control and intervention day

• Muscle fatigue: Change of static force control

  Change between 30 min before the beginning of the simulated working activity and 30 min after the end of the simulated working activity of both the control and intervention day

• Muscle fatigue: Change of force control in ramp contraction

  Change between 30 min before the beginning of the simulated working activity and 30 min after the end of the simulated working activity of both the control and intervention day

Other Outcomes (5)

• Localized musculoskeletal discomfort

  At the start, and 70min, 130min, 190min, 310min, 370 min after the beginning of the simulated working activity of both the control and intervention day

• Visual and general fatigue

  At the start, and 70min, 130min, 190min, 310min, 370 min after the beginning of the simulated working activity of both the control and intervention day

• Effort

  At the start, and 70min, 130min, 190min, 310min, 370 min after the beginning of the simulated working activity of both the control and intervention day

Study Arms (1)

short interruptions of work tasks

EXPERIMENTAL

randomly start with or without short interruptions on the first experimental day and without or with them on the second experimental day

Behavioral: interruptions of work tasks

Interventions

interruptions of work tasks BEHAVIORAL

During each activity two interruptions/breaks were selected randomly from a set of ten predetermined actions: Active break types: * Move shoulder and upper back * Swing arms near the body * Three slow but forceful elevations of the shoulders, a relaxation exercise based on the principles developed by Jacobson * Stand up and stretch * Slowly turn head in all possible directions. Passive break types: * Tell a couple of jokes * Stand up and have a drink * Relaxing the trapezius * Questions on actual posture and feelings of comfort / discomfort. * A short rest on the couch

short interruptions of work tasks

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• healthy experienced computer workers

You may not qualify if:

• chronic pain (more than 30 days within the last 12 months according to the Nordic Questionnaire (Kuorinka et al 1987);
• pathologies of the neck,
• prior and actual shoulder or neck pain caused by an accident,
• skin disease in the neck or shoulder area,
• BMI \> 30,
• sleep disorders (e.g. apnea, restless legs syndrome),
• use of medications such as psychotropic drugs, muscle relaxants or analgesics within the last 3 days prior to the experiment,
• pregnancy.
• any shoulder/neck pain on the day before the experiment.

Sponsors & Collaborators

• Swiss Federal Institute of Technology: lead
• University of Turin, Italy: collaborator
• University of Lausanne: collaborator
• University of Michigan: collaborator

Study Officials

• Thomas Läubli, MD

  Federal Institute of Technology Zurich

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Masking: NONE
• Masking Details: Participants were informed that the study investigates neuro-motor mechanisms but not about the more specific research questions.
• Purpose: PREVENTION
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomized controlled laboratory experiment. 30 subjects are randomly assigned to two full day experiments either starting with the conditions including additional short interventions or without them.

Study Record Dates

• First Submitted: December 14, 2018
• First Posted: March 5, 2019
• Study Start: March 14, 2016
• Primary Completion: September 5, 2016
• Study Completion: September 5, 2016
• Last Updated: March 5, 2019

Record last verified: 2019-02

Data Sharing

• IPD Sharing: Will not share