Clinical trial NCT06995469: Efficacy of a Passive Lower Limb Exoskeleton in Reducing Plantar Pressure and Injuries From Prolonged Standing
Official title: Efficacy of a Passive Lower Limb Exoskeleton on Plantar Pressure Distribution to Reduce on Plantar Pressure Distribution to Reduce Prolonged Standing Injuries: Prolonged Standing Injuries
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Health-Related Behavior
Keywords: Passive exoskeleton
Lower limbs
Prolonged standing
Plantar pressure
Occupational ergonomics
Lead sponsor: Fundación Universidad Católica de Valencia San Vicente Mártir
Sponsor class: OTHER
First posted: 2025-05-29
Enrollment: 25
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: The study population consists of adults aged 18-65 who work in roles requiring ≥4 hours of standing daily, with at least 6 months of continuous experience. Participants were selected through purposive sampling based on specific inclusion/exclusion criteria. Individuals with diagnosed musculoskeletal or circulatory disorders or those already using orthopedic/ergonomic devices were excluded. This group reflects a real-world ergonomic risk population, suitable for assessing the preventive efficacy of a passive lower limb exoskeleton in the workplace.

Brief summary: This quasi-experimental study evaluates the effectiveness of a passive lower-limb exoskeleton (Chairless Chair® 2.0) in redistributing plantar pressure and reducing injuries caused by prolonged standing in workplace settings. Conducted on 25 participants, the research measured plantar pressure, body sway, and postural stability with and without the exoskeleton using a pressure platform. Additionally, user fatigue and satisfaction were assessed through validated questionnaires (Borg CR10, QUEST 2.0). The results aim to determine the device's preventive potential regarding musculoskeletal and circulatory issues, contributing to improved ergonomic health and work performance.

Detailed description: Prolonged standing is a common requirement in various professional sectors (e.g., healthcare, industry), and is associated with increased risks of musculoskeletal and circulatory disorders, especially in the lower limbs. Conditions such as plantar fasciitis, chronic venous insufficiency, and pressure ulcers are prevalent. These affect worker health, comfort, and productivity, and impose economic burdens on employers and healthcare systems.

Objective To evaluate the effectiveness of a passive exoskeleton for the lower limbs (Chairless Chair® 2.0) in redistributing plantar pressure and reducing musculoskeletal injuries associated with prolonged standing. The study also investigates the device's influence on postural stability, perceived fatigue, and user comfort.

Methodology Study design: Quasi-experimental with repeated measures (participants act as their own control).

Participants: 25 adult workers (aged 18-60), with ≥6 months of exposure to prolonged standing at work. Exclusion criteria included pre-existing musculoskeletal or circulatory disorders and use of orthopedic devices.

Device: Chairless Chair® 2.0 by Noonee Germany GmbH-a passive, non-powered exoskeleton enabling users to alternate between standing and semi-sitting positions.

Tools and Measurements:

Podoprint S4 pressure platform to measure:

Plantar pressure distribution (forefoot, midfoot, heel)

Body sway and stability (center of pressure displacement)

CR10 Borg scale for fatigue

QUEST 2.0 for usability and satisfaction

Data Analysis:

Quantitative analysis using SPSS and JASP

Paired t-tests or Wilcoxon tests for comparisons

Spearman correlations and Chi-square tests for categorical relationships

Statistical significance set at p \< 0.05

Key Variables Dependent: Plantar pressure (kPa), body sway (cm²), postural stability (mm/s), fatigue perception, comfort.

Independent: Use of exoskeleton, age, gender, BMI, type of footwear, reported discomfort.

Ethical and Legal Framework Ethical approval granted by the Comité de Ética de la Universidad Católica de Valencia (CEI).

Compliance with LOPDGDD, GDPR, and Declaration of Helsinki.

Informed consent obtained; anonymity and data protection were strictly maintained.

Expected Outcomes Reduction in peak plantar pressure and postural sway when using the exoskeleton.

Improvement in stability and fatigue levels.

Enhanced user comfort and satisfaction, making the device a feasible ergonomic intervention.

Significance This study seeks to fill a gap in scientific literature regarding the biomechanical benefits of passive lower-limb exoskeletons in real work environments, providing evidence for their role in injury prevention, ergonomic improvement, and worker well-being.

Eligibility criteria: Inclusion Criteria:

Adults aged 18 to 60 years

Currently employed in jobs requiring prolonged standing (≥4 hours/day)

Minimum 6 months of work experience in such standing-intensive roles

Physically capable of performing normal job tasks

Able and willing to provide informed consent

Exclusion Criteria:

Diagnosis of musculoskeletal or circulatory conditions (e.g., plantar fasciitis, varicose veins, chronic venous insufficiency)

Current use of orthopedic or ergonomic devices, such as foot orthoses

Uncontrolled medical conditions that may pose a risk (e.g., uncontrolled hypertension)

Pregnancy

Inability to understand or comply with study procedures

Primary outcomes:
measure: Change in Plantar Pressure Distribution With vs. Without Passive Exoskeleton Use Change in Plantar Pressure Distribution With vs. Without Passive Exoskeleton Use Change in Plantar Pressure Distribution With vs. Without Passive Exoskeleton Use
timeFrame: Immediately after task performance in each condition (with and without exoskeleton) - approximately same workday or within 1-2 days
Secondary outcomes:
measure: Change in Postural Stability With vs. Without Passive Exoskeleton
timeFrame: Immediately after task performance in each condition (with and without exoskeleton)
measure: Perceived Fatigue After Work Tasks With vs. Without Exoskeleton
timeFrame: Immediately after task completion in each condition - within same workday
measure: User Comfort and Usability of the Passive Exoskeleton
timeFrame: After using the exoskeleton during a full work session - within 1 day
Other outcomes:
Locations:
city: Valencia
country: Spain
facility: Clinicas UCV
state: València
Study officials:
affiliation: UNIVERSIDAD CATOLICA DE VALENCIA
name: JAVIER FERRER TORREGROSA, Dr.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Liu L, Wei W, Zheng K, Diao Y, Wang Z, Li G, Zhao G. Design of an Unpowered Ankle-Foot Exoskeleton Used for Walking Assistance. Annu Int Conf IEEE Eng Med Biol Soc. 2021 Nov;2021:4501-4504. doi: 10.1109/EMBC46164.2021.9630707.
citation: Steinhilber B, Seibt R, Rieger MA, Luger T. Postural Control When Using an Industrial Lower Limb Exoskeleton: Impact of Reaching for a Working Tool and External Perturbation. Hum Factors. 2022 Jun;64(4):635-648. doi: 10.1177/0018720820957466. Epub 2020 Sep 28.
citation: Kong YK, Park CW, Cho MU, Kim SY, Kim MJ, Hyun DJ, Bae K, Choi JK, Ko SM, Choi KH. Guidelines for Working Heights of the Lower-Limb Exoskeleton (CEX) Based on Ergonomic Evaluations. Int J Environ Res Public Health. 2021 May 13;18(10):5199. doi: 10.3390/ijerph18105199.