Chairless Chair Exoskeleton. Work-physiological-biomechanical Analysis of the Lower Extremities

NCT03134144 | Completed Results

• 1 other identifier: UKT-2017-AS0-1569
• Study Type: interventional
• Target: 46
• Locations: 1 country
• Sites: 1

Brief Summary

Standing work is associated with increased risks of venous and musculoskeletal disorders; particularly low back pain is commonly reported in prolonged standing work. In manufacturing work, workstations often do not allow standing aids due to insufficient functional and spatial conditions. In 2014, the car manufacturer Audi introduced the lower leg exoskeleton developed by Noonee to their employees working in the factories. This exoskeleton, the 'Chairless Chair' has the advantage that standing work can be performed while technically sitting on this device. The exoskeleton offers the potential for reduced awkward body postures, but it is unclear which physiological and biomechanical loads are influenced and how. This proposal provides a study design evaluating the 'Chairless Chair' in a laboratory setting, by testing its effectiveness in terms of physiological and biomechanical parameters. It is suggested to compare different assembly tasks while wearing the exoskeleton, compared with not wearing the exoskeleton. The 'Chairless Chair' is developed in one size only, which is why we propose to include participants of different body height, which will enable us to investigate whether body height influences the effectiveness of wearing the device.

Conditions

Healthy

Keywords

Exoskeleton; Manual materials handling; Musculoskeletal disorders; Posture; Standing work; Muscle activity

Outcome Measures

Primary Outcomes (2)

• Center of Pressure

  Indicator for the balance of the study participants. This outcome was measured using a force plate, in which the anteroposterior and mediolateral directions of the center of pressure are recorded. The center of pressure is a visual projection of the center of mass of the participant. For the anteroposterior direction of the center of pressure, a positive value \[mm\] represents the anterior direction and a negative value \[mm\] represents the posterior direction. For the mediolateral direction of the center of pressure, a positive value \[mm\] represents the right-lateral direction and a negative value \[mm\] represents the left-lateral direction. For this outcome, we recorded the anteroposterior direction of the center of pressure. The outcome is in mm, where neg. reflects the posterior direction and pos. the anterior direction.

  10 minutes of 2 hours

• Muscle Activity of the Lower Back (M. Erector Spinae Lumbalis)

  Indicator for the muscular load in the lower back (M. erector spinae lumbalis) that may change when wearing the passive exoskeleton. The muscle activity was recorded using bipolar surface electromyography, during which two electrodes are placed on the muscle belly. The absolute value of muscle activity recordings is in microvolt, but since this is difficult to interpret, we have normalized this to a reference voluntary contraction that was executed by each participant prior to the experiment. The unit of measure for normalized muscle activity therefore is a percentage, i.e. a percentage of the electrical activity during the reference voluntary contraction \[%RVE\].

  10 minutes of 2 hours

Secondary Outcomes (3)

• Back Posture: Upper Back Forward Flexion Angle With Respect to the Perpendicular (Earth)

  10 minutes of 2 hours

• Subjective Feeling of Overall Discomfort

  10 minutes of 2 hours

• Participant Evaluation

  2 hours

Study Arms (2)

First without exoskeleton then with exoskeleton

EXPERIMENTAL

Subject will perform the conditions as described under "model description" first without the exoskeleton and then with the exoskeleton.

Device: Exoskeleton "Chairless Chair"

First with exoskeleton then without exoskeleton

EXPERIMENTAL

Subject will perform the conditions as described under "model description" first with the exoskeleton and then without the exoskeleton.

Device: Exoskeleton "Chairless Chair"

Interventions

Exoskeleton "Chairless Chair" DEVICE

One solution to reduce the exposure of employees to associated risks for developing work-related musculoskeletal disorders is to use exoskeletons. Using such a device in dynamic environments has the advantage over, e.g., robotics because it does not need any programming or teaching of robots. Moreover, exoskeletons are worn at the body and do not have to overcome spatial issues. In a recent review, 26 different exoskeletons have been described of which only two were designed to support the lower body during heavy work (de Looze et al. 2015). For lower intensive work tasks, like assembly tasks in the automobile industry, no study has focused on using exoskeletons to relieve employees while performing the work standing.

First with exoskeleton then without exoskeleton; First without exoskeleton then with exoskeleton

Eligibility Criteria

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

You may qualify if:

• Age: between 18 and 40 years old;
• Gender: male;
• Voluntary informed consent (oral and written) is obligatory for study participation.

You may not qualify if:

• Age: \<18 and \>40 years old;
• Gender: female;
• People under the influence of intoxicants, analgesics, or muscle relaxants;
• Alcohol abuse;
• People with cardiovascular diseases;
• People with a heart pacemaker;
• People with a disability who, due to their restriction at a workplace of this kind, will not be able to participate;
• People with Diabetes Mellitus;
• People with severe muscle contractions of the lower extremities, back or arms;
• People with acute ailments or pain;
• People who are unable to complete the examination program due to language or cognitive obstacles;
• Depending on the degree of severity, people with diseases of the veins and joints of the lower extremities, spine, muscle disorders, symptomatic neurological-psychiatric diseases, acute pain syndromes, maladies or other current diseases.

Sponsors & Collaborators

• University Hospital Tuebingen: lead

Study Sites (1)

Institute for Occupational and Social Medicine and Health Services Research, University Hospital Tübingen, Faculty of Medicine, Eberhard Karls University Tübingen

Tübingen, Baden-Wurttemberg, 72074, Germany

Location

Related Publications (2)

• Luger T, Seibt R, Cobb TJ, Rieger MA, Steinhilber B. Influence of a passive lower-limb exoskeleton during simulated industrial work tasks on physical load, upper body posture, postural control and discomfort. Appl Ergon. 2019 Oct;80:152-160. doi: 10.1016/j.apergo.2019.05.018. Epub 2019 May 30.

  PMID: 31280799 RESULT

• Luger T, Cobb TJ, Seibt R, Rieger MA, Steinhilber B. Subjective Evaluation of a Passive Lower-Limb Industrial Exoskeleton Used During simulated Assembly. IISE Transactions on Occupational Ergonomics and Human Factors, 2018.

  RESULT

Related Links

• Page 78: oral presentation of the study at the PREMUS 2019 conference in Bologna, Italy.

MeSH Terms

Conditions

Musculoskeletal Diseases

Results Point of Contact

• Title: Tessy Luger
• Organization: Institute of Occupational and Social Medicine and Health Services Research, University of Tübingen

Tessy.Luger@med.uni-tuebingen.de

004970712984364

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: April 25, 2017
• First Posted: April 28, 2017
• Study Start: May 1, 2017
• Primary Completion: October 15, 2017
• Study Completion: October 15, 2017
• Last Updated: June 16, 2020
• Results First Posted: June 16, 2020

Record last verified: 2020-06

Locations

DE (1)