HealthyNCT05347810
Comfort Thresholds for Repetitive Forces
A study testing Application of repetitive forces mimicking exoskeleton use in people with Healthy, run by Roessingh Research and Development at 1 site in Netherlands.
Trial summary
Exoskeletons can be used for rehabilitation, as assistive device for patients, or to support workers during strenuous tasks. To fulfil their purpose, they need to apply forces to the user's musculoskeletal system. The forces are transmitted at skin level through an interface, often in the form of cuffs. Read more about this study
- Who is it for?
- Ages 18 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Application of repetitive forces mimicking exoskeleton use
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteNetherlands
- Study dates
- 11 May 2022to 10 Jun 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Between 18 and 35 or between 55 and 85 years of age
- Able to provide informed consent
Who cannot join
- Unable to follow simple instructions
- Insufficient knowledge of the Dutch or English language to understand the purpose and methods of the study
- skin lesions at the thigh
- sensory impairments
- severe blood pressure fluctuations
- inability to sit in required posture in experiment chair for 60 minutes
- taking blood thinners or showing signs for increased bleeding tendency
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Comfort During Prolonged Exposure to Repetitive Forces Mimicking Exoskeleton Use
Exoskeletons can be used for rehabilitation, as assistive device for patients, or to support workers during strenuous tasks. To fulfil their purpose, they need to apply forces to the user's musculoskeletal system. The forces are transmitted at skin level through an interface, often in the form of cuffs. Adverse events causing discomfort and injuries to the skin and underlying tissue can be attributed to those interaction forces. While there is some information about safe limit values for impact forces or pressure and shear applied for short durations, little is known regarding comfort and safety thresholds for repetitive forces applied over long durations as is the case in exoskeleton use. This study therefore aims at gaining new knowledge on safe and limit values, based on discomfort (staying below pain threshold), for continuous repetitive shear and normal forces applied through a cuff.
Therefore, the primary objective is to determine comfort thresholds for prolonged exposure to repetitive normal and shear stress exerted to the human thigh via a cuff with straps, using different force patterns comparable to those exerted during exoskeleton use. The secondary objectives are to determine the feasibility of the experiment, the influence of subject characteristics on comfort thresholds, the occurrence of skin injuries or other negative signs, and whether characteristics of muscle activity can be related to discomfort.
Read the detailed description
Rationale: Exoskeletons can be used for rehabilitation, as assistive device for patients, or to support workers during strenuous tasks. To fulfil their purpose, they need to apply forces to the user's musculoskeletal system. The forces are transmitted at skin level through an interface, often in the form of cuffs. Adverse events causing discomfort and injuries to the skin and underlying tissue can be attributed to those interaction forces. While there is some information about safe limit values for impact forces or pressure and shear applied for short durations, little is known regarding comfort and safety thresholds for repetitive forces applied over long durations as is the case in exoskeleton use. This study therefore aims at gaining new knowledge on safe and limit values, based on discomfort (staying below pain threshold), for continuous repetitive shear and normal forces applied through a cuff.
Objective: The primary objective is to determine comfort thresholds for prolonged exposure to repetitive normal and shear stress exerted to the human thigh via a cuff with straps, using different force patterns comparable to those exerted during exoskeleton use. The secondary objectives are to determine the feasibility of the experiment, the influence of subject characteristics on comfort thresholds, the occurrence of skin injuries or other negative signs, and whether characteristics of muscle activity can be related to discomfort.
Study design: The study is a cross-sectional intervention study with one measurement session, where participants will provide a continuous comfort rating during exposure to repetitive normal and shear forces.
Study population: The aim is to include 20 healthy participants in total, matching the age groups 18-35 and 55-85.
Intervention: A pre-defined set of prolonged repetitive force patterns will be applied to each participant's thigh though a contact force which is similar to cuffs commonly used in gait exoskeletons. The forces will be applied by a custom made actuated test device and are based on normal use of exoskeletons.
Main study parameters/endpoints: The main study parameter is the level of discomfort as indicated continuously by the participants through a slider with a visual analogue scale. The scale reaches from no discomfort at all to maximum imaginable discomfort. A separate switch which releases all forces if activated by the participant is used to detect onset of pain.
Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The study is non-therapeutic, so no direct benefits for the participants are involved. The procedures are non-invasive and safety measures are taken to avoid excessive force exertion to the participants or other unsafe situations. Therefore, subjects suffer no negative effects or disadvantages, except for the invested time and the discomfort experienced during the force execution. Pain will be avoided as participants can trigger a release of the forces at any time. Any changes to the participants' skin or other negative signs will be monitored and followed up on until they have resolved.
- Conditions
- Healthy
- Being tested
- Application of repetitive forces mimicking exoskeleton use
- Keywords
- Exoskeleton, Safety, Comfort, physical Human-Robot Interaction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Application of repetitive forces mimicking exoskeleton useOther
The investigational treatment consists of applying a predefined set of continuous and repetitive forces to the participant's thigh. It is applied using a custom device that has been designed specifically for this study. The forces to be applied are based on forces measured during exoskeleton use and will not exceed pain pressure thresholds reported in literature. The participants will hold an enabling switch at all times which they can activate to release the force exerted to their thigh. Alternatively, the experimenter can activate an emergency switch if the situation seems unsafe.
| Study group | Role | What they receive |
|---|---|---|
| Study group | Experimental | All participants in the study will receive the same investigational treatment (application of prolonged repetitive forces) and provide continuous comfort ratings. Receives: Other: Application of repetitive forces mimicking exoskeleton use |
What is being measured
The primary outcome is the main question the study is designed to answer.
Perceived discomfort as indicated on a 10 mm visual analog scale (VAS) by the participants, ranking from 'no discomfort' to 'worst imaginable comfort' (10)
The level of discomfort will be indicated on a VAS as a percentage of maximum imaginable discomfort through a slider that is positioned within reach of the subjects. It will be synchronized with the forces exerted in relation to time. The onset of discomfort, i.e. the point at which the slider of the VAS is first moved to a position >0, is recorded as discomfort detection threshold (DDT). If the participant activates the enabling switch indicating that the force creates pain rather than discomfort, this point is recorded as pain detection threshold (PDT).
Measured: 80 minutes
Secondary outcomes (3)
Number of completed test sessions/dropouts
To investigate feasibility and tolerability of experiments
Measured: 160 minutes
Occurrence of injuries or other negative signs
Records of skin changes directly after the sessions and short structured interview on the phone 2-4 days after the intervention
Measured: 30 minutes
Surface Electromyography (EMG) recordings of Rectus femoris
Muscle activity
Measured: 120 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Apr 2022
- Study start11 May 2022
- Primary completion10 Jun 2022
- Study completion10 Jun 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- 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
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- The study is a cross-sectional intervention study with one measurement session, where participants will provide a continuous comfort rating during exposure to repetitive normal and shear forces.
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- Roessingh Research and Development
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Gerdienke Prange, PhD, Principal investigator, Roessingh Research and Development
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05347810
- Sponsor's protocol ID
- 80800
- Status last verified
- Jun 2022
- First submitted
- 29 Mar 2022
- Last updated
- 22 Jun 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Jun 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comfort During Prolonged Exposure to Repetitive Forces Mimicking Exoskeleton Use
- ClinicalTrials.gov ID
- NCT05347810
- Acronym / sponsor ID
- 80800
- Conditions
- Healthy
- Keywords
- Exoskeleton, Safety, Comfort, physical Human-Robot Interaction
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- Roessingh Research and DevelopmentUniversity, hospital or other
- Study start
- 11 May 2022 (actual)
- Primary completion
- 10 Jun 2022 (actual)
- Study completion
- 10 Jun 2022 (actual)
- First posted
- 26 Apr 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Exoskeletons can be used for rehabilitation, as assistive device for patients, or to support workers during strenuous tasks. To fulfil their purpose, they need to apply forces to the user's musculoskeletal system. The forces are transmitted at skin level through an interface, often in the form of cuffs. Adverse events causing discomfort and injuries to the skin and underlying tissue can be attributed to those interaction forces. While there is some information about safe limit values for impact forces or pressure and shear applied for short durations, little is known regarding comfort and safety thresholds for repetitive forces applied over long durations as is the case in exoskeleton use. This study therefore aims at gaining new knowledge on safe and limit values, based on discomfort (staying below pain threshold), for continuous repetitive shear and normal forces applied through a cuff.
Therefore, the primary objective is to determine comfort thresholds for prolonged exposure to repetitive normal and shear stress exerted to the human thigh via a cuff with straps, using different force patterns comparable to those exerted during exoskeleton use. The secondary objectives are to determine the feasibility of the experiment, the influence of subject characteristics on comfort thresholds, the occurrence of skin injuries or other negative signs, and whether characteristics of muscle activity can be related to discomfort.
Detailed description
Rationale: Exoskeletons can be used for rehabilitation, as assistive device for patients, or to support workers during strenuous tasks. To fulfil their purpose, they need to apply forces to the user's musculoskeletal system. The forces are transmitted at skin level through an interface, often in the form of cuffs. Adverse events causing discomfort and injuries to the skin and underlying tissue can be attributed to those interaction forces. While there is some information about safe limit values for impact forces or pressure and shear applied for short durations, little is known regarding comfort and safety thresholds for repetitive forces applied over long durations as is the case in exoskeleton use. This study therefore aims at gaining new knowledge on safe and limit values, based on discomfort (staying below pain threshold), for continuous repetitive shear and normal forces applied through a cuff.
Objective: The primary objective is to determine comfort thresholds for prolonged exposure to repetitive normal and shear stress exerted to the human thigh via a cuff with straps, using different force patterns comparable to those exerted during exoskeleton use. The secondary objectives are to determine the feasibility of the experiment, the influence of subject characteristics on comfort thresholds, the occurrence of skin injuries or other negative signs, and whether characteristics of muscle activity can be related to discomfort.
Study design: The study is a cross-sectional intervention study with one measurement session, where participants will provide a continuous comfort rating during exposure to repetitive normal and shear forces.
Study population: The aim is to include 20 healthy participants in total, matching the age groups 18-35 and 55-85.
Intervention: A pre-defined set of prolonged repetitive force patterns will be applied to each participant's thigh though a contact force which is similar to cuffs commonly used in gait exoskeletons. The forces will be applied by a custom made actuated test device and are based on normal use of exoskeletons.
Main study parameters/endpoints: The main study parameter is the level of discomfort as indicated continuously by the participants through a slider with a visual analogue scale. The scale reaches from no discomfort at all to maximum imaginable discomfort. A separate switch which releases all forces if activated by the participant is used to detect onset of pain.
Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The study is non-therapeutic, so no direct benefits for the participants are involved. The procedures are non-invasive and safety measures are taken to avoid excessive force exertion to the participants or other unsafe situations. Therefore, subjects suffer no negative effects or disadvantages, except for the invested time and the discomfort experienced during the force execution. Pain will be avoided as participants can trigger a release of the forces at any time. Any changes to the participants' skin or other negative signs will be monitored and followed up on until they have resolved.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- The study is a cross-sectional intervention study with one measurement session, where participants will provide a continuous comfort rating during exposure to repetitive normal and shear forces.
| Arm | Type | Receives |
|---|---|---|
| Study group | Experimental | Other: Application of repetitive forces mimicking exoskeleton useAll participants in the study will receive the same investigational treatment (application of prolonged repetitive forces) and provide continuous comfort ratings. |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Between 18 and 35 or between 55 and 85 years of age
- Able to provide informed consent
Key exclusion criteria (7 listed)
- Unable to follow simple instructions
- Insufficient knowledge of the Dutch or English language to understand the purpose and methods of the study
- skin lesions at the thigh
- sensory impairments
- severe blood pressure fluctuations
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 |
|---|---|---|
| Application of repetitive forces mimicking exoskeleton useThe investigational treatment consists of applying a predefined set of continuous and repetitive forces to the participant's thigh. It is applied using a custom device that has been designed specifically for this study. The forces to be applied are based on forces measured during exoskeleton use and will not exceed pain pressure thresholds reported in literature. The participants will hold an enabling switch at all times which they can activate to release the force exerted to their thigh. Alternatively, the experimenter can activate an emergency switch if the situation seems unsafe. | Other | Study group |
Primary outcome
Perceived discomfort as indicated on a 10 mm visual analog scale (VAS) by the participants, ranking from 'no discomfort' to 'worst imaginable comfort' (10)
Time frame: 80 minutes
The level of discomfort will be indicated on a VAS as a percentage of maximum imaginable discomfort through a slider that is positioned within reach of the subjects. It will be synchronized with the forces exerted in relation to time. The onset of discomfort, i.e. the point at which the slider of the VAS is first moved to a position >0, is recorded as discomfort detection threshold (DDT). If the participant activates the enabling switch indicating that the force creates pain rather than discomfort, this point is recorded as pain detection threshold (PDT).
3 secondary outcomes
Number of completed test sessions/dropouts
Time frame: 160 minutes
Occurrence of injuries or other negative signs
Time frame: 30 minutes
Surface Electromyography (EMG) recordings of Rectus femoris
Time frame: 120 minutes
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Jun 2022.
- 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.
Gerdienke Prange, PhD principal investigator
Roessingh Research and Development
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Application of repetitive forces mimicking exoskeleton use in people with Healthy, run by Roessingh Research and Development at 1 site in Netherlands.
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 2 inclusion and 7 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 22 Jun 2022. 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 Netherlands. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Perceived discomfort as indicated on a 10 mm visual analog scale (VAS) by the participants, ranking from 'no discomfort' to 'worst imaginable comfort' (10) (time frame: 80 minutes). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 22 Jun 2022.