Neuromuscular Control and Motor Unit Behavior in Patients With Knee Osteoarthritis

Neuromuscular Control and Motor Unit Behavior in Patients With Knee Osteoarthritis: a Randomized Single-blind Trial of Muscle Training and Knee Orthosis Intervention

This study aims to examine the effects of moderate-intensity strength training, performed with or without an unloading knee orthosis (valgus-corrective or sham mode), on muscle function, motor unit behavior, and force modulation in patients with moderate knee osteoarthritis

Study Overview

• Status: Not yet recruiting
• Conditions: Knee Osteoarthritis (Knee OA)
• Intervention / Treatment: Behavioral: the strengthening program

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

- 1. age 55 to 75 years.

2. Diagnosed with moderate knee traumatic arthritis (Kellgren-Lawrence classification II or III)(experimental group).

The control group must not have a diagnosis of osteoarthritis of the knee and must have normal knee joint function.

3. Physical Health Status: Able to perform basic movements requiring isometric knee contraction tests and electromyography recording.

4. Able to wear knee orthotics.

Exclusion Criteria:

• 1. Knee or lower extremity injury: Recent (within the past 6 months) history of severe injury, fracture, or surgery to the knee or lower extremity.

  2. Other joint disorders: Coexisting joint disorders (such as rheumatoid arthritis or gouty arthritis).

  3. Neuromuscular disorders: Presence of neuromuscular dysfunction, such as stroke, Parkinson's disease, or peripheral neuropathy.

  4. Uncontrolled cardiovascular disease, hypertension, diabetes, or other medical conditions.

Taking medications that affect neuromuscular function.

5. Allergy or intolerance: Allergy to laboratory equipment (such as electromyography electrode gel) or knee brace materials.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: controls group	Behavioral: the strengthening program; The isometric knee-extension strengthening program from session 1 to session 9 as follows: Before the first training session each week, one-repetition maximum (1RM) will be measured to determine the training intensity for that week.; Training frequency: Three sessions per week on non-consecutive days, for a total of 3 weeks (9 sessions).; Training intensity: 60% of 1RM. The goal is to improve quadriceps strength and endurance while reducing joint loading.; Each session will consist of four sets: 30 repetitions in the first set and 15 repetitions in sets 2-4.; Rest intervals of 30 seconds will be provided between sets, during which the blood-flow-restriction device will remain in place.
Experimental: Group A with the corrective knee orthosis; patients with moderate knee osteoarthritis (Kellgren-Lawrence grade II-III) who will receive a valgus-corrective knee orthosis.	Behavioral: the strengthening program; The isometric knee-extension strengthening program from session 1 to session 9 as follows: Before the first training session each week, one-repetition maximum (1RM) will be measured to determine the training intensity for that week.; Training frequency: Three sessions per week on non-consecutive days, for a total of 3 weeks (9 sessions).; Training intensity: 60% of 1RM. The goal is to improve quadriceps strength and endurance while reducing joint loading.; Each session will consist of four sets: 30 repetitions in the first set and 15 repetitions in sets 2-4.; Rest intervals of 30 seconds will be provided between sets, during which the blood-flow-restriction device will remain in place.
Placebo Comparator: Group B without the corrective knee orthosis; patients with moderate knee osteoarthritis (Kellgren-Lawrence grade II-III) who will not receive a valgus-corrective knee orthosis.	Behavioral: the strengthening program; The isometric knee-extension strengthening program from session 1 to session 9 as follows: Before the first training session each week, one-repetition maximum (1RM) will be measured to determine the training intensity for that week.; Training frequency: Three sessions per week on non-consecutive days, for a total of 3 weeks (9 sessions).; Training intensity: 60% of 1RM. The goal is to improve quadriceps strength and endurance while reducing joint loading.; Each session will consist of four sets: 30 repetitions in the first set and 15 repetitions in sets 2-4.; Rest intervals of 30 seconds will be provided between sets, during which the blood-flow-restriction device will remain in place.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
maximal voluntary isometric contraction (MVC)		Baseline and 3 weeks
The Western Ontario and McMaster Universities Turkish (WOMAC) index	a self-administered questionnaire that assesses three aspects of a patient's health status -pain, stiffness, and physical function - in those with lower limb Osteoarthritis. WOMAC consists of 24 questions, with a total score ranging from 0 to 96 points. there are three subscales: pain (5 questions), stiffness (2 questions), and physical function (17 questions). a five-tier classification of symptomatic severity: minimal or no symptoms (≤24 score), mild (25-41 score), moderate (42-69 score), severe (70-86 score), and extreme (≥87 score).	baseline, 3 weeks
The Knee Injury and Osteoarthritis Outcome Score (KOOS)	a knee-specific instrument, developed to assess the patients' opinion about their knee and associated problems. Knee Injury and Osteoarthritis Outcome Score (KOOS) has five subscales: pain (9 questions), symptoms (7 questions), activities of daily living (17 questions), sport/recreation (5 questions), knee-related quality of life (4 questions). The total score of each question (0-4 points) is converted into a score of 0-100, where 100 points represents the best knee health and 0 points represents the worst.	Baseline and 3 weeks
Motor Unit Recruitment (amplitude relative to recruitment threshold)	surface EMG decomposition	Baseline and 3 weeks
Motor Unit Recruitment (firing rate relative to recruitment threshold)	surface EMG decomposition	Baseline and 3 weeks

Collaborators and Investigators

• Sponsor: Kaohsiung Veterans General Hospital.

Study record dates

Study Major Dates

• Study Start (Estimated): April 20, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: April 12, 2026
• First Submitted That Met QC Criteria: April 18, 2026
• First Posted (Actual): April 22, 2026

Study Record Updates

• Last Update Posted (Actual): April 22, 2026
• Last Update Submitted That Met QC Criteria: April 18, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: knee osteoarthritis; Orthotic Devices
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: A-ER-114-259

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No