NCT07424352 · University of Colorado, Denver
Knee Osteoarthritis Rehabilitation Through Rotational Inertia
(KORRI)
What this study is about
This study is testing whether a new type of exercise program, called eccentric overload training using a flywheel device, can improve stair-climbing ability in people with knee osteoarthritis. The flywheel device provides resistance throughout the entire movement and gives extra challenge during the muscle-lengthening phase of exercise.
View original scientific description
This study is testing whether a new type of exercise program, called eccentric overload training using a flywheel device, can improve stair-climbing ability in people with knee osteoarthritis. The flywheel device provides resistance throughout the entire movement and gives extra challenge during the muscle-lengthening phase of exercise. This type of training may improve muscle structure, strength, and coordination more effectively than conventional methods. The study's central idea is that better muscle quality and improved coordination will lead to smoother, safer stair movement and reduce the risk of falls. Advanced tools such as ultrasound imaging and motion analysis will be used to measure muscle health and movement patterns in detail. The hypothesis is that individuals with knee osteoarthritis have poorer muscle quality and less coordinated stair-stepping compared to healthy adults, and that performing eccentric overload training will enhance muscle quality, improve movement coordination, and make stair navigation safer and more efficient.
Interventions
OTHER
Eccentric resistance training
The intervention consists of an eccentric overload resistance training program using a portable flywheel exercise device (kBox). This device generates resistance through inertia, meaning that the load is created by the individual's own movement speed and the effort applied. Participants with knee osteoarthritis will train with the flywheel system for 8 weeks, completing two to three sessions each week, with each session lasting approximately 30 to 45 minutes. The program will focus on functional lower-limb exercises such as squats, step-ups, and knee extensions. These exercises are chosen because they closely mimic everyday movements like climbing and descending stairs. Participants randomized to the delayed-exercise subgroup will continue with usual activity and medical care for the first 8 weeks, serving as a comparison group. After this waiting period, the delayed group will then be offered the same flywheel training protocol.
Primary outcome measures
Stair-stepping smoothness
Time frame: Baseline, up to 10 weeks, up to 19 weeks
Stair-stepping smoothness quantifies motor coordination during the step-up-and-over test by analyzing the fluidity and consistency of limb movements while ascending and descending stairs. It is calculated using a jerk-based smoothness metric adapted from Gonzales et al., where jerk is defined as the third derivative of the position trajectory with respect to time. The smoothness index is derived by numerically differentiating the position data x(t) obtained from motion capture three times to calculate jerk, then squaring and summing these jerk values over the duration of the movement. Lower values of the smoothness index indicate smoother, more coordinated movements. Differences in this metric will be compared between knee osteoarthritis patients and age-matched healthy controls, with variance explained through linear regression models, and between exercise intervention and delayed exercise subgroups to assess changes in motor control during stair negotiation. Unitless.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Osteoarthritis (OA) Group:
- Aged 40-70 years
- Radiographically confirmed knee OA (Kellgren-Lawrence \[KL\] Grade 2 or 3)
- Able to walk independently (assistive devices permitted) Inclusion Criteria Healthy Control Group:
- Aged 40-70 years
- No radiographic evidence of knee OA (KL Grade 0 or 1)
- No frequent knee pain
- No history of:
- Knee surgery (e.g., ACL reconstruction, meniscectomy, patellar realignment)
- Significant knee injury (e.g., ligament tears, fractures, dislocations)
- Diagnosed knee conditions (e.g., patellofemoral pain syndrome, bursitis)
Exclusion criteria
- Uncontrolled hypertension or other cardiovascular disease
- A musculoskeletal condition preventing physical testing
- Neurological muscle weakness (e.g., stroke, spinal cord injury)
- BMI \>34.9 kg/m²
- Recent hospitalization (past 3 months)
Where
- Aurora, Colorado
Collaborators
NIH/NCATS Colorado CTSA Grant Number T32TR004367
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Feb 20, 2026 · Source of record for eligibility and locations