Passive Upper-limb ExoskeletonADVANCENCT03725982
Work Physiological-Biomechanical Analysis of a Passive Exoskeleton to Support Occupational Lifting and Flexing Processes
A study testing Laevo ® and No Laevo ® in people with Passive Upper-limb Exoskeleton, run by University Hospital Tuebingen at 1 site in Germany.
Trial summary
BACKGROUND Industrial tasks that are characterized by high loads, a high repetition rate, and/or awkward body postures, put employees at higher risk to develop work-related musculoskeletal disorders (WRMSD), especially low back pain. Read more about this study
- Who is it for?
- Ages 18 to 40 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Passive Upper-limb Exoskeleton
- What is being tested?
- Laevo ® and No Laevo ®
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 39 participants
- Where
- 1 siteGermany
- Study dates
- 18 Jan 2019to 22 May 2019
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- The participant will give his voluntary informed consent after receiving oral and written information of the content and goal of the study.
Who cannot join
- Aged <18 and >40 years;
- Female;
- BMI > 30 kg/m2;
- People under the influence of intoxicants, analgesics, or muscle relaxants;
- Alcohol abuse;
- People with cardiovascular diseases;
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- 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.
Trial locations and contacts
1 site in 1 country.
Germany1 site
Institute of Occupational and Social Medicine and Health Services Research, University Hospital Tübingen
Tübingen, Baden-Wurttemberg, 72074
About this study
BACKGROUND Industrial tasks that are characterized by high loads, a high repetition rate, and/or awkward body postures, put employees at higher risk to develop work-related musculoskeletal disorders (WRMSD), especially low back pain. To counteract the prevalence of WRMSD, human-robot interaction could improve the power of a person and reduce the physical strain. For the lower back, a reduction of spinal loading could be helpful. The passive upper-extremity exoskeleton Laevo® is developed to support physically heavy work: it supports the back during bending and should, consequently, result in less low back pain (Laevo®, the Netherlands).
OBJECTIVES The primary aim of this study is to assess to what extent wearing the exoskeleton changes:
Read more
- muscular activity of the erector spinae and biceps femoris muscles;
- knee compression force;
- posture of the upper and lower spine, trunk, hips and knees; ...in different tasks (static vs. dynamic), different trunk postures (trunk flexion vs. trunk flexion and rotation) and different knee postures (straight vs. stooped).
Secondary aims of this study are to assess to what extent wearing the exoskeleton changes:
- muscular activity of the trapezius descendens, rectus abdominis, vastus medialis and gastrocnemius medialis;
- perceived discomfort;
- heart rate;
- internal loadings on the spine, using a lumbar spine model;
- the performance of subjects during functional activities (e.g., stair climbing) when wearing the exoskeleton (either turned on or off); ...in different tasks (static vs. dynamic), different trunk postures (trunk flexion vs. trunk flexion and rotation), different knee postures (stoop vs. squat), and different static holding positions(0° vs. 30° vs. 60°) with different weights (0kg vs. 8kg vs. 16kg).
Read the detailed description
METHODS Different experiments will be performed.
- The investigators will test six different experimental conditions in the laboratory, which are a combination of exoskeleton (with vs. without Laevo®), task (static vs. dynamic), and knee angle only for the dynamic task (flexed vs. extended). Within each combination, the investigators will test three different working directions (front vs. left vs. right), realized by changing the working posture (trunk flexion vs. left trunk rotation vs. right trunk rotation). Using the single Williams design for six conditions, the investigators estimated the sample size to include 36 subjects (i.e., a multiple of six). Using a force plate, acceleration and postural sensors, knee compression force can be estimated using 2D inverse modelling. With an electromyographic system, the muscle activity of selected target muscles at different body parts (i.e., legs, trunk, and shoulders) can be recorded. The heart rate will be recorded using electrocardiography.
- The investigators will test four different conditions, which are a combination of exoskeleton (with vs. without Laevo®) and knee angle (flexed vs. extended). Within each combination, the investigators will test three different loads carried (0kg, 8kg, 16kg) and five different trunk flexion angles (0°, 30°, 60°, 60°, 30°). Muscle activity, position, heart rate and ground reaction forces will be recorded.
- The investigators will test three different functional tests. The outcomes for this aim are time recorded for performing the functional or industrial task and perceived difficulty rated on an 11-point numeric rating scale.
- The investigators will use the lumbar spine model developed by the research group Biomechanics and Biorobotics of the research cluster Simulation Technology of the University of Stuttgart. The model includes a detailed lumber spine with non-linear discs, ligaments, and muscles. Using the measurements of the experiment, this model is able to predict how internal forces in the lumbar spine change as a result of external forces (i.e., wearing and using the Laevo® exoskeleton).
ANALYSES Depending on the outcome parameter, different analyses will be performed including a various number of independent variables.
- The effects of exoskeleton (with vs. without), task (static vs. dynamic), knee angle (flexed vs. extended; only for the dynamic task), and working posture (trunk flexion vs. left trunk rotation vs. right trunk rotation) will be assessed using a four-factor repeated-measures analysis of variance (RM-ANOVA) or a generalized estimating equation (GEE) which is more robust.
- The effects of exoskeleton (with vs. without), knee angle (flexed vs. extended), load carried (0kg vs. 8kg vs. 16kg), and trunk flexion angle (0° vs. 30° vs. 60°) will be assessed using a RM-ANOVA or GEE.
- The effect of exoskeleton (with vs. without) on time and perceived difficulty of each functional or industrial test will be assessed using a paired T-Test. In addition, the muscular load of several muscles will also be evaluated.
DATA PROTECTION All participating subjects will receive a refund of € 45 after study completion. Subjects will sign an informed consent and their data will be numerically pseudonymized to guarantee anonymity.
SIMULATED TASKS
- Static sorting task, lasting 1.5 minutes, within which subjects are exposed to 6 experimental conditions: exoskeleton (2 levels: without vs. with) X working posture (3 levels: left trunk rotation vs. frontal orientation vs. right trunk rotation).
- Dynamic lifting task, two sets of five repetitions each, within which subjects are exposed to 12 experimental conditons: exoskeleton (2 levels: without vs. with) X working posture (3 levels: left trunk rotation vs. frontal orientation vs. right trunk rotation) X knee angle (2 levels: extended/stoop vs. bent/squat).
- Functional tasks: a course within which several occupationally relevant tasks (picking \& placing, drilling) and standardized tests (sit-up-and-stand, stair walk) are evaluated on performance, subjectively perceived strain and muscle load.
- Static holding task, for which subjects were exposed to 18 different conditions: exoskeleton (2 levels: without vs. with) X holding weight (3 levels: 0kg vs. 8kg vs. 16kg) X trunk flexion angle (3 levels: 0° vs. 30° vs. 60°).
IMPORTANT NOTE --- On this platform, results of the static sorting task ONLY will be reported. Results of other parts of the study will be reported in the respective publication. Links to these publications will be added as soon as they are published and available. --- IMPORTANT NOTE
- Conditions
- Passive Upper-limb Exoskeleton
- Being tested
- Laevo ®, No Laevo ®
- Keywords
- passive exoskeleton, forward trunk flexion, trunk rotation, muscle activity, inverse dynamics, modelling
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Laevo ®Device
Also called Exoskeleton
A passive exoskeleton supporting the lower back during bending and lifting tasks (for more information, visit the manufacturer's website: http://en.laevo.nl/).
No Laevo ®Device
Also called No exoskeleton
The subjects will not wear any supporting device to perform the experiment, which serves as the control condition.
| Study group | Role | What they receive |
|---|---|---|
| With exoskeleton, then without exoskeleton | Experimental | Subject will first perform the conditions (simulated, simplified, industrial standing work) with the exoskeleton, then without the exoskeleton. Receives: Device: Laevo ®; Device: No Laevo ® |
| Without exoskeleton, then with exoskeleton | Experimental | Subject will first perform the conditions (simulated, simplified, industrial standing work) without the exoskeleton, then with the exoskeleton. Receives: Device: Laevo ®; Device: No Laevo ® |
What is being measured
The primary outcome is the main question the study is designed to answer.
Muscular Activity of Erector Spinae Muscle.
Root-mean-square (RMS) of the electrical activity of the erector spinae muscle using surface electromyography (sEMG). The sEMG signals will be continuously recorded, and the RMS will be normalized to a maximal voluntary contraction (%MVE) and averaged over the time period of each experimental condition.
Measured: Average RMS-value (%MVE) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition
Muscular Activity of Biceps Femoris Muscle.
Root-mean-square (RMS) of the electrical activity of the biceps femoris muscle using surface electromyography (sEMG). The sEMG signals will be continuously recorded, and the RMS will be normalized to a reference voluntary contraction (%RVE) and averaged over the time period of each experimental condition.
Measured: Average RMS-value (%RVE) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition
Posture (Thoracic Kyphosis)
The posture of the upper spine (thoracic kyphosis) determined using 2D gravimetric position sensors placed on the thoracic vertebrae T1 and lumbar vertebrae L1. The difference value between both sensors reflects the thoracic kyphosis, which was averaged over each experimental condition.
Measured: Average thoracic kyphosis over time period baseline (0 min) to directly after (1.5 min) the experimental condition
Posture (Lumbar Lordosis)
The posture of the lower spine (lumbar lordosis) determined using 2D gravimetric position sensors placed on the lumbar vertebrae L1 and L5. The difference value between both sensors reflects the lumbar lordosis, which was averaged over each experimental condition.
Measured: Average lumbar lordosis over time period baseline (0 min) to directly after (1.5 min) the experimental condition
Posture (Trunk Flexion)
The posture of the trunk determined using a 2D gravimetric position sensor placed on the thoracic vertebrae T10. The flexion angle of the sensor was averaged over each experimental condition.
Measured: Average trunk flexion over time period baseline (0 min) to directly after (1.5 min) the experimental condition
Posture (Hip Flexion)
The posture of the hip (hip flexion) determined using 2D gravimetric position sensors placed on the lumbar vertebrae L5 and the upper leg (femur). The difference value between both sensors reflects the hip flexion, which was averaged over each experimental condition.
Measured: Average hip flexion over time period baseline (0 min) to directly after (1.5 min) the experimental condition
Posture (Knee Flexion)
The posture of the knee (knee flexion) determined using 2D gravimetric position sensors placed on the upper leg (femur) and lower leg (tibia). The difference value between both sensors reflects the knee flexion, which was averaged over each experimental condition.
Measured: Average knee flexion over time period baseline (0 min) to directly after (1.5 min) the experimental condition
Knee Compression Force
The knee compression force (KCF) is calculated using 2D inverse modelling with continuous recordings from 2D gravimetric position sensors (for joint angles) and a force plate (for ground reaction forces). The average knee compression force will be calculated over each experimental condition and summarized for both the left and right knee, since the task is executed in the frontal plane.
Measured: Average knee compression force (KCF) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition
Secondary outcomes (5)
Muscular Activity of Rectus Abdominis, Vastus Lateralis, Gastrocnemius Medialis and Trapezius Descendens Muscles.
Root-mean-square (RMS) of the electrical activity of the rectus abdominis, vastus lateralis, gastrocnemius medialis and trapezius descendens muscles using surface electromyography (sEMG). The sEMG signals will be continuously recorded, and the RMS will be normalized to a refeernce voluntary contraction (%RVE) and averaged over the time period of each experimental condition.
Measured: Average RMS-value (%RVE) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition.
Rating of Perceived Discomfort (RPD)
Discomfort (RPD) was assessed using an 11-point numeric rating scale (NRS), ranging from 0 (no discomfort at all) to 10 (maximally imaginable discomfort). It was assessed directly before (0 min) and directly after (1.5 min) each experimental condition. The experimental conditions consisted of either static or dynamic tasks, that lasted up to 1.5 minutes.
Measured: Change from baseline (0 min) to directly after (1.5 min) both experimental conditions
Heart Rate
Continuous recording electrocardiography allows calculating the heart rate, a parameter reflecting the central stress state of the participant. The average heart rate will be calculated per time period.
Measured: Average heart activity over time period baseline (0 min) to directly after (1.5 min) the experimental condition
Evaluation of Workload
The NASA Task Load Index (TLX) of Hart and Staveland (1988) will be used to evaluate workload. This standardized tool contains six dimensions (mental demand, physical demand, temporal demand, own performance, effort, frustration), of which each scale ranges from from 0 (low) to 100 (high).
We will include three dimensions of interest, i.e. physical demand, temporal demand, effort, and calculate the unweighted average of the score of these three dimensions (Hoonakker et al. 2011).
Measured: Directly after the experimental condition during which the exoskeleton was worn (~ 4.5-6.5 min)
Self-developed Participant Evaluation Questionnaire
This questionnaire will consist of questions about usability and acceptance of the intervention (the Laevo device), stemming from standardized questions from existing questionnaires, including:
- the System Usability Scale (SUS): 10 statements about subjective perception of interaction with the Laevo system to be evaluated on a scale ranging from 1 (disagree) to 5 (agree);
- the Technology Usage Inventory (TUI): 30 statements on technology-specific and psychological factors with respect to the Laevo to be evaluated on a scale ranging from 1 (not true) to 7 (true); of these 30 questions, the investigators include only 7 statements belonging to the domains 'usability' and 'skepticism'.
The questionnaire can only be filled out after the condition within which the technology (here: exoskeleton) was used. That means that results are only provided and, thus, reported from the arm "with exoskeleton".
Measured: Directly after the experiment (~2.5 hours)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Oct 2018
- Study start18 Jan 2019
- Primary completion15 May 2019
- Study completion22 May 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Passive Upper-limb ExoskeletonStudies of the same condition, open and under way.
- More trials run by University Hospital TuebingenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- 1. Static sorting Six conditions as combination of exoskeleton (without vs. with) and trunk posture (forward flexion vs. flexion + rotation left vs. flexion + rotation right) are investigated in a randomized order. 2. Dynamic lifting Twelve conditions as combination of exoskeleton (without vs. with), work posture (forward flexion vs. flexion + rotation left vs. flexion + rotation right) and knee angle (extended/stoop vs. flexed/squat) are investigated in randomized order. 3. Functional tasks Three tests with two conditions in randomized order (exoskeleton: without vs. with) will be investigated in fixed order (stair-climbing; timed-up-and-go; course with various simulated industrial workstations). 4. Angle-force relation Twelve conditions as combination of exoskeleton (without vs. with), knee angle (extended/stoop vs. flexed/squat) and trunk flexion angle (0 vs. 30 vs. 60 degrees) are investigated in randmized order.
- Masking
- None (open label)
- Enrolment
- 39 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital Tuebingen
- Sponsor type
- University, hospital or other
- Collaborators
- Audi AG, BASF, BMW AG, Dachser Intelligent Logistics, Daimler AG, Deutsche Post AG, Iturri Gruppe, MTU Aero Engines AG
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03725982
- Sponsor's protocol ID
- UKT-2018-AS0-1836
- Acronym
- ADVANCE
- Status last verified
- May 2019
- First submitted
- 27 Sep 2018
- Last updated
- 12 Jul 2023
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Luger T, Bar M, Seibt R, Rieger MA, Steinhilber B. Using a Back Exoskeleton During Industrial and Functional Tasks-Effects on Muscle Activity, Posture, Performance, Usability, and Wearer Discomfort in a Laboratory Trial. Hum Factors. 2023 Feb;65(1):5-21. doi: 10.1177/00187208211007267. Epub 2021 Apr 16.
PubMed 33861139Luger T, Bar M, Seibt R, Rimmele P, Rieger MA, Steinhilber B. A passive back exoskeleton supporting symmetric and asymmetric lifting in stoop and squat posture reduces trunk and hip extensor muscle activity and adjusts body posture - A laboratory study. Appl Ergon. 2021 Nov;97:103530. doi: 10.1016/j.apergo.2021.103530. Epub 2021 Jul 16.
PubMed 34280658
Study at a glance
From the registry record, last updated by the sponsor on 12 Jul 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Work Physiological-Biomechanical Analysis of a Passive Exoskeleton to Support Occupational Lifting and Flexing Processes
- ClinicalTrials.gov ID
- NCT03725982
- Acronym / sponsor ID
- ADVANCE / UKT-2018-AS0-1836
- Conditions
- Passive Upper-limb Exoskeleton
- Keywords
- passive exoskeleton, forward trunk flexion, trunk rotation, muscle activity, inverse dynamics, modelling
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 39 participants (actual)
- Lead sponsor
- University Hospital TuebingenUniversity, hospital or other
- Collaborators
- Audi AG, BASF, BMW AG, Dachser Intelligent Logistics, Daimler AG, Deutsche Post AG, Iturri Gruppe, MTU Aero Engines AG
- Study start
- 18 Jan 2019 (actual)
- Primary completion
- 15 May 2019 (actual)
- Study completion
- 22 May 2019 (actual)
- First posted
- 31 Oct 2018 (actual)
- Results
- Posted 31 Mar 2020
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
BACKGROUND Industrial tasks that are characterized by high loads, a high repetition rate, and/or awkward body postures, put employees at higher risk to develop work-related musculoskeletal disorders (WRMSD), especially low back pain. To counteract the prevalence of WRMSD, human-robot interaction could improve the power of a person and reduce the physical strain. For the lower back, a reduction of spinal loading could be helpful. The passive upper-extremity exoskeleton Laevo® is developed to support physically heavy work: it supports the back during bending and should, consequently, result in less low back pain (Laevo®, the Netherlands).
OBJECTIVES The primary aim of this study is to assess to what extent wearing the exoskeleton changes:
- muscular activity of the erector spinae and biceps femoris muscles;
- knee compression force;
- posture of the upper and lower spine, trunk, hips and knees; ...in different tasks (static vs. dynamic), different trunk postures (trunk flexion vs. trunk flexion and rotation) and different knee postures (straight vs. stooped).
Secondary aims of this study are to assess to what extent wearing the exoskeleton changes:
- muscular activity of the trapezius descendens, rectus abdominis, vastus medialis and gastrocnemius medialis;
- perceived discomfort;
- heart rate;
- internal loadings on the spine, using a lumbar spine model;
- the performance of subjects during functional activities (e.g., stair climbing) when wearing the exoskeleton (either turned on or off); ...in different tasks (static vs. dynamic), different trunk postures (trunk flexion vs. trunk flexion and rotation), different knee postures (stoop vs. squat), and different static holding positions(0° vs. 30° vs. 60°) with different weights (0kg vs. 8kg vs. 16kg).
Detailed description
METHODS Different experiments will be performed.
- The investigators will test six different experimental conditions in the laboratory, which are a combination of exoskeleton (with vs. without Laevo®), task (static vs. dynamic), and knee angle only for the dynamic task (flexed vs. extended). Within each combination, the investigators will test three different working directions (front vs. left vs. right), realized by changing the working posture (trunk flexion vs. left trunk rotation vs. right trunk rotation). Using the single Williams design for six conditions, the investigators estimated the sample size to include 36 subjects (i.e., a multiple of six). Using a force plate, acceleration and postural sensors, knee compression force can be estimated using 2D inverse modelling. With an electromyographic system, the muscle activity of selected target muscles at different body parts (i.e., legs, trunk, and shoulders) can be recorded. The heart rate will be recorded using electrocardiography.
- The investigators will test four different conditions, which are a combination of exoskeleton (with vs. without Laevo®) and knee angle (flexed vs. extended). Within each combination, the investigators will test three different loads carried (0kg, 8kg, 16kg) and five different trunk flexion angles (0°, 30°, 60°, 60°, 30°). Muscle activity, position, heart rate and ground reaction forces will be recorded.
- The investigators will test three different functional tests. The outcomes for this aim are time recorded for performing the functional or industrial task and perceived difficulty rated on an 11-point numeric rating scale.
- The investigators will use the lumbar spine model developed by the research group Biomechanics and Biorobotics of the research cluster Simulation Technology of the University of Stuttgart. The model includes a detailed lumber spine with non-linear discs, ligaments, and muscles. Using the measurements of the experiment, this model is able to predict how internal forces in the lumbar spine change as a result of external forces (i.e., wearing and using the Laevo® exoskeleton).
ANALYSES Depending on the outcome parameter, different analyses will be performed including a various number of independent variables.
- The effects of exoskeleton (with vs. without), task (static vs. dynamic), knee angle (flexed vs. extended; only for the dynamic task), and working posture (trunk flexion vs. left trunk rotation vs. right trunk rotation) will be assessed using a four-factor repeated-measures analysis of variance (RM-ANOVA) or a generalized estimating equation (GEE) which is more robust.
- The effects of exoskeleton (with vs. without), knee angle (flexed vs. extended), load carried (0kg vs. 8kg vs. 16kg), and trunk flexion angle (0° vs. 30° vs. 60°) will be assessed using a RM-ANOVA or GEE.
- The effect of exoskeleton (with vs. without) on time and perceived difficulty of each functional or industrial test will be assessed using a paired T-Test. In addition, the muscular load of several muscles will also be evaluated.
DATA PROTECTION All participating subjects will receive a refund of € 45 after study completion. Subjects will sign an informed consent and their data will be numerically pseudonymized to guarantee anonymity.
SIMULATED TASKS
- Static sorting task, lasting 1.5 minutes, within which subjects are exposed to 6 experimental conditions: exoskeleton (2 levels: without vs. with) X working posture (3 levels: left trunk rotation vs. frontal orientation vs. right trunk rotation).
- Dynamic lifting task, two sets of five repetitions each, within which subjects are exposed to 12 experimental conditons: exoskeleton (2 levels: without vs. with) X working posture (3 levels: left trunk rotation vs. frontal orientation vs. right trunk rotation) X knee angle (2 levels: extended/stoop vs. bent/squat).
- Functional tasks: a course within which several occupationally relevant tasks (picking \& placing, drilling) and standardized tests (sit-up-and-stand, stair walk) are evaluated on performance, subjectively perceived strain and muscle load.
- Static holding task, for which subjects were exposed to 18 different conditions: exoskeleton (2 levels: without vs. with) X holding weight (3 levels: 0kg vs. 8kg vs. 16kg) X trunk flexion angle (3 levels: 0° vs. 30° vs. 60°).
IMPORTANT NOTE --- On this platform, results of the static sorting task ONLY will be reported. Results of other parts of the study will be reported in the respective publication. Links to these publications will be added as soon as they are published and available. --- IMPORTANT NOTE
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- 1. Static sorting Six conditions as combination of exoskeleton (without vs. with) and trunk posture (forward flexion vs. flexion + rotation left vs. flexion + rotation right) are investigated in a randomized order. 2. Dynamic lifting Twelve conditions as combination of exoskeleton (without vs. with), work posture (forward flexion vs. flexion + rotation left vs. flexion + rotation right) and knee angle (extended/stoop vs. flexed/squat) are investigated in randomized order. 3. Functional tasks Three tests with two conditions in randomized order (exoskeleton: without vs. with) will be investigated in fixed order (stair-climbing; timed-up-and-go; course with various simulated industrial workstations). 4. Angle-force relation Twelve conditions as combination of exoskeleton (without vs. with), knee angle (extended/stoop vs. flexed/squat) and trunk flexion angle (0 vs. 30 vs. 60 degrees) are investigated in randmized order.
| Arm | Type | Receives |
|---|---|---|
| With exoskeleton, then without exoskeleton | Experimental | Device: Laevo ®, Device: No Laevo ®Subject will first perform the conditions (simulated, simplified, industrial standing work) with the exoskeleton, then without the exoskeleton. |
| Without exoskeleton, then with exoskeleton | Experimental | Device: Laevo ®, Device: No Laevo ®Subject will first perform the conditions (simulated, simplified, industrial standing work) without the exoskeleton, then with the exoskeleton. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- The participant will give his voluntary informed consent after receiving oral and written information of the content and goal of the study.
Key exclusion criteria (13 listed)
- Aged <18 and >40 years;
- Female;
- BMI > 30 kg/m2;
- People under the influence of intoxicants, analgesics, or muscle relaxants;
- Alcohol abuse;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Laevo ®Also: ExoskeletonA passive exoskeleton supporting the lower back during bending and lifting tasks (for more information, visit the manufacturer's website: http://en.laevo.nl/). | Device | With exoskeleton, then without exoskeleton, Without exoskeleton, then with exoskeleton |
| No Laevo ®Also: No exoskeletonThe subjects will not wear any supporting device to perform the experiment, which serves as the control condition. | Device | With exoskeleton, then without exoskeleton, Without exoskeleton, then with exoskeleton |
Primary outcome
Muscular Activity of Erector Spinae Muscle.
Time frame: Average RMS-value (%MVE) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition
Root-mean-square (RMS) of the electrical activity of the erector spinae muscle using surface electromyography (sEMG). The sEMG signals will be continuously recorded, and the RMS will be normalized to a maximal voluntary contraction (%MVE) and averaged over the time period of each experimental condition.
Muscular Activity of Biceps Femoris Muscle.
Time frame: Average RMS-value (%RVE) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition
Root-mean-square (RMS) of the electrical activity of the biceps femoris muscle using surface electromyography (sEMG). The sEMG signals will be continuously recorded, and the RMS will be normalized to a reference voluntary contraction (%RVE) and averaged over the time period of each experimental condition.
Posture (Thoracic Kyphosis)
Time frame: Average thoracic kyphosis over time period baseline (0 min) to directly after (1.5 min) the experimental condition
The posture of the upper spine (thoracic kyphosis) determined using 2D gravimetric position sensors placed on the thoracic vertebrae T1 and lumbar vertebrae L1. The difference value between both sensors reflects the thoracic kyphosis, which was averaged over each experimental condition.
Posture (Lumbar Lordosis)
Time frame: Average lumbar lordosis over time period baseline (0 min) to directly after (1.5 min) the experimental condition
The posture of the lower spine (lumbar lordosis) determined using 2D gravimetric position sensors placed on the lumbar vertebrae L1 and L5. The difference value between both sensors reflects the lumbar lordosis, which was averaged over each experimental condition.
Posture (Trunk Flexion)
Time frame: Average trunk flexion over time period baseline (0 min) to directly after (1.5 min) the experimental condition
The posture of the trunk determined using a 2D gravimetric position sensor placed on the thoracic vertebrae T10. The flexion angle of the sensor was averaged over each experimental condition.
Posture (Hip Flexion)
Time frame: Average hip flexion over time period baseline (0 min) to directly after (1.5 min) the experimental condition
The posture of the hip (hip flexion) determined using 2D gravimetric position sensors placed on the lumbar vertebrae L5 and the upper leg (femur). The difference value between both sensors reflects the hip flexion, which was averaged over each experimental condition.
Posture (Knee Flexion)
Time frame: Average knee flexion over time period baseline (0 min) to directly after (1.5 min) the experimental condition
The posture of the knee (knee flexion) determined using 2D gravimetric position sensors placed on the upper leg (femur) and lower leg (tibia). The difference value between both sensors reflects the knee flexion, which was averaged over each experimental condition.
Knee Compression Force
Time frame: Average knee compression force (KCF) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition
The knee compression force (KCF) is calculated using 2D inverse modelling with continuous recordings from 2D gravimetric position sensors (for joint angles) and a force plate (for ground reaction forces). The average knee compression force will be calculated over each experimental condition and summarized for both the left and right knee, since the task is executed in the frontal plane.
5 secondary outcomes
Muscular Activity of Rectus Abdominis, Vastus Lateralis, Gastrocnemius Medialis and Trapezius Descendens Muscles.
Time frame: Average RMS-value (%RVE) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition.
Rating of Perceived Discomfort (RPD)
Time frame: Change from baseline (0 min) to directly after (1.5 min) both experimental conditions
Heart Rate
Time frame: Average heart activity over time period baseline (0 min) to directly after (1.5 min) the experimental condition
Evaluation of Workload
Time frame: Directly after the experimental condition during which the exoskeleton was worn (~ 4.5-6.5 min)
Self-developed Participant Evaluation Questionnaire
Time frame: Directly after the experiment (~2.5 hours)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Jul 2023.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Results publication: PubMed 33861139Luger T, Bar M, Seibt R, Rieger MA, Steinhilber B. Using a Back Exoskeleton During Industrial and Functional Tasks-Effects on Muscle Activity, Posture, Performance, Usability, and Wearer Discomfort in a Laboratory Trial. Hum Factors. 2023 Feb;65(1):5-21. doi: 10.1177/00187208211007267. Epub 2021 Apr 16.
- Results publication: PubMed 34280658Luger T, Bar M, Seibt R, Rimmele P, Rieger MA, Steinhilber B. A passive back exoskeleton supporting symmetric and asymmetric lifting in stoop and squat posture reduces trunk and hip extensor muscle activity and adjusts body posture - A laboratory study. Appl Ergon. 2021 Nov;97:103530. doi: 10.1016/j.apergo.2021.103530. Epub 2021 Jul 16.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Laevo ® and No Laevo ® in people with Passive Upper-limb Exoskeleton, run by University Hospital Tuebingen at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 12 Jul 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 31 Mar 2020). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Muscular Activity of Erector Spinae Muscle. (time frame: Average RMS-value (%MVE) over the time period running from baseline (0 min) to directly after (1.5 min) the experimental condition). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03725982, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jul 2023.