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
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
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.
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.
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