Robot-Aided Off-Axis Neuromuscular Training for Knee OA

NCT07014098 | Not Yet Recruiting DMC

• 1 other identifier: HP-00113883
• Study Type: interventional
• Target: 36
• Locations: 0 countries
• Sites: N/A

Brief Summary

Although the primary knee motion occurs in flexion/extension, the frontal and transverse (off-axis) knee motions are smaller but crucial for maintaining joint stability and normal knee loading. Altered kinematics and neuromuscular control in off-axis knee motions have been reported in patients with knee osteoarthritis (OA), which are associated with excessive knee loading and the progression of knee OA. However, traditional rehabilitative treatments for people with knee OA and existing exercise equipment often focus on sagittal plane movement. Probably due to the technical limitations, there is a lack of convenient and effective equipment/method to train patients with knee OA in off-axis (frontal and transverse) planes. The purpose of this study is to use a robot-aided elliptical training device to measure knee neuromechanical properties and to improve neuromuscular control in off-axis knee motions, aiming for joint de-loading and pain reduction for individuals with knee OA.

Conditions

Osteoarthritis of Knee

Keywords

knee osteoarthritis; robot-assisted; neuromuscular training; knee biomechanics; knee symptoms; evaluation-based training strategy

Outcome Measures

Primary Outcomes (2)

• Peak knee adduction moment

  Baseline, immediately after the 5-week training, and follow-up evaluation 8-week post-training

• Knee pain

  Questionnaires, including the Knee Injury and Osteoarthritis Outcome Score (KOOS)

  Baseline, immediately after the 5-week training, and follow-up evaluation 8-week post-training

Secondary Outcomes (4)

• Knee proprioception acuity/pain in off-axis directions

  Baseline, immediately after the 5-week training, and follow-up evaluation 8-week post-training

• Knee range of motions/stiffness/laxity in off-axis directions

  Baseline, immediately after the 5-week training, and follow-up evaluation 8-week post-training

• Functional ability

  Baseline, immediately after the 5-week training, and follow-up evaluation 8-week post-training

• Heath-related quality of life

  Baseline, immediately after the 5-week training, and follow-up evaluation 8-week post-training

Study Arms (2)

evaluation-based, progressive, off-axis neuromuscular training group

EXPERIMENTAL

Device: Robot-Aided Off-Axis Neuromuscular Training

traditional elliptical regular stepping group

SHAM COMPARATOR

Device: Traditional elliptical regular stepping

Interventions

Traditional elliptical regular stepping DEVICE

traditional elliptical regular stepping

traditional elliptical regular stepping group

Robot-Aided Off-Axis Neuromuscular Training DEVICE

A novel custom-designed elliptical trainer is developed, and its footplates are robot-controlled to be moved in four off-axis directions (sliding in/out, pivoting in/out; corresponding to knee valgus/varus, internal rotation/external rotation). Before the training, off-axis neuromechanical assessments will be conducted to determine which specific off-axis direction (valgus, varus, internal rotation, external rotation, or combination of the off-axis directions) has neuromechanical deficits. During the evaluation-based and subject-specific neuromuscular training, the different training modes will be conducted progressively from regular stepping, footplate position control, spring mode, perturbation, to slippery mode.

evaluation-based, progressive, off-axis neuromuscular training group

Eligibility Criteria

• Age: 45 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 45 - 85 years.
• Meets the ACR classification criteria for knee OA (clinical + radiographic criteria); Kellgren-Lawrence grade I-III.
• Persistent knee pain ≥ 3 months.
• Able to independently complete elliptical training (6 minutes without interruption).

You may not qualify if:

• Other inflammatory joint diseases (e.g., rheumatoid arthritis).
• Knee trauma, surgery, or intra-articular injections within the past year.
• History of knee or hip replacement.
• Cardiovascular disease or uncontrolled hypertension contradict to exercises.
• Cognitive impairment (Montreal cognitive assessment \< 22).
• Currently participating in another interventional study for the lower limb.
• Neurological impairment (e.g., stroke, Parkinson's disease, radicular pain).

Sponsors & Collaborators

• University of Maryland, Baltimore: lead

Related Publications (11)

• Lee SJ, Ren Y, Geiger F, Chang AH, Press JM, Zhang LQ. Offaxis neuromuscular training of knee injuries using an offaxis robotic elliptical trainer. Annu Int Conf IEEE Eng Med Biol Soc. 2011;2011:2081-4. doi: 10.1109/IEMBS.2011.6090386.

  PMID: 22254747 BACKGROUND

• Griffin LY, Agel J, Albohm MJ, Arendt EA, Dick RW, Garrett WE, Garrick JG, Hewett TE, Huston L, Ireland ML, Johnson RJ, Kibler WB, Lephart S, Lewis JL, Lindenfeld TN, Mandelbaum BR, Marchak P, Teitz CC, Wojtys EM. Noncontact anterior cruciate ligament injuries: risk factors and prevention strategies. J Am Acad Orthop Surg. 2000 May-Jun;8(3):141-50. doi: 10.5435/00124635-200005000-00001.

  PMID: 10874221 BACKGROUND

• Williams GN, Chmielewski T, Rudolph K, Buchanan TS, Snyder-Mackler L. Dynamic knee stability: current theory and implications for clinicians and scientists. J Orthop Sports Phys Ther. 2001 Oct;31(10):546-66. doi: 10.2519/jospt.2001.31.10.546.

  PMID: 11665743 BACKGROUND

• Ren Y, Lee SJ, Park HS, Zhang LQ. A pivoting elliptical training system for improving pivoting neuromuscular control and rehabilitating musculoskeletal injuries. IEEE Trans Neural Syst Rehabil Eng. 2013 Sep;21(5):860-8. doi: 10.1109/TNSRE.2013.2273874.

  PMID: 24013591 BACKGROUND

• Lee SJ, Ren Y, Geiger F, Zhang LQ. Gender differences in offaxis neuromuscular control during stepping under a slippery condition. Eur J Appl Physiol. 2013 Nov;113(11):2857-66. doi: 10.1007/s00421-013-2727-3. Epub 2013 Sep 24.

  PMID: 24062010 BACKGROUND

• Kang SH, Lee SJ, Ren Y, Zhang LQ. Real-time knee adduction moment feedback training using an elliptical trainer. IEEE Trans Neural Syst Rehabil Eng. 2014 Mar;22(2):334-43. doi: 10.1109/TNSRE.2013.2291203.

  PMID: 24608687 BACKGROUND

• Tsai LC, Lee SJ, Yang AJ, Ren Y, Press JM, Zhang LQ. Effects of Off-Axis Elliptical Training on Reducing Pain and Improving Knee Function in Individuals With Patellofemoral Pain. Clin J Sport Med. 2015 Nov;25(6):487-93. doi: 10.1097/JSM.0000000000000164.

  PMID: 25591131 BACKGROUND

• Lin CY, Tsai LC, Press J, Ren Y, Chung SG, Zhang LQ. Lower-Limb Muscle-Activation Patterns During Off-Axis Elliptical Compared With Conventional Gluteal-Muscle-Strengthening Exercises. J Sport Rehabil. 2016 May;25(2):164-72. doi: 10.1123/jsr.2014-0307. Epub 2015 May 6.

  PMID: 25946669 BACKGROUND

• Lee SJ, Ren Y, Press JM, Lee J, Zhang LQ. Improvement in Offaxis Neuromuscular Control Under Slippery Conditions Following Six-Week Pivoting Leg Neuromuscular Training. IEEE Trans Neural Syst Rehabil Eng. 2017 Nov;25(11):2084-2093. doi: 10.1109/TNSRE.2017.2705664. Epub 2017 May 18.

  PMID: 28541212 BACKGROUND

• Lauder TD, Baker SP, Smith GS, Lincoln AE. Sports and physical training injury hospitalizations in the army. Am J Prev Med. 2000 Apr;18(3 Suppl):118-28. doi: 10.1016/s0749-3797(99)00174-9.

  PMID: 10736548 BACKGROUND

• Hootman JM, Dick R, Agel J. Epidemiology of collegiate injuries for 15 sports: summary and recommendations for injury prevention initiatives. J Athl Train. 2007 Apr-Jun;42(2):311-9.

  PMID: 17710181 BACKGROUND

MeSH Terms

Conditions

Osteoarthritis, Knee

Condition Hierarchy (Ancestors)

Osteoarthritis; Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases

Study Officials

• Li-Qun Zhang, PhD

  University of Maryland, Baltimore

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Zongpan Li, PhD

CONTACT

410-706-5717; zongpan.li@som.umaryland.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: April 25, 2025
• First Posted: June 10, 2025
• Study Start: May 1, 2026
• Primary Completion (Estimated): June 1, 2029
• Study Completion (Estimated): January 1, 2030
• Last Updated: April 21, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, CSR
• Time Frame: The IPD and supporting information will be available from Oct 2025, for 5 years.
• Access Criteria: Who: Researchers (academic, clinical, or industry) who provide a methodologically sound proposal for approved scientific use. Regulatory authorities (e.g., FDA, EMA) for review and compliance verification. Ethics committees or auditors for validation of study integrity. What: De-identified participant-level data (demographics, outcomes, lab results, etc.). Study documents, such as protocols, statistical analysis plans, and case report forms. Clinical study reports (CSRs) with anonymized results. How: Researchers must submit a formal proposal to a designated data-sharing platform (e.g., ClinicalStudyDataRequest.com) or the study sponsor. Approved requesters sign a data use agreement (DUA) and receive secure access via encrypted repositories or controlled cloud-based platforms.