Knee OsteoarthritisNCT07456254
Effect of 0° and 50° N-K Table Load Angles on Quadriceps Activation in Knee Osteoarthritis
A study testing Isotonic Quadriceps Exercise Using NK Table in people with Knee Osteoarthritis and Osteearthritis, run by Universitas Indonesia at 1 site in Indonesia.
Trial summary
Knee osteoarthritis (OA) is a common degenerative joint disease that leads to pain, reduced mobility, and functional limitation. Quadriceps femoris weakness plays a significant role in disease progression and disability. Read more about this study
- Who is it for?
- Ages 50 to 65 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Knee Osteoarthritis, Osteearthritis
- What is being tested?
- Isotonic Quadriceps Exercise Using NK Table
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 43 participants
- Where
- 1 siteIndonesia
- Study dates
- 20 Jan 2024to 25 May 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 65 years
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Diagnosed with unilateral or bilateral knee osteoarthritis (OA), grade 2 or 3, in the subacute or chronic phase based on the criteria of the American College of Rheumatology (ACR) and Kellgren-Lawrence classification.
- Female, aged 50-65 years, based on ACR diagnostic criteria.
- Knee flexion-extension range of motion of at least 0-120 degrees.
- Normal cognitive function as assessed using the Montreal Cognitive Assessment Indonesia Version (MoCA-INA) (score ≥26-30)
Who cannot join
- Knee joint instability due to ligament laxity in the cruciate or collateral ligaments obtained from physical examination (valgus/varus test and anterior/posterior drawer test) or previous supporting examination.
- Presence of deformity in the form of genu varus, genu valgus, or genu recurvatum (Q angle 12-20°).
- History of knee injury (fracture, ligament rupture, or meniscus) or having undergone knee surgery.
- Pain or instability of the ankle joint obtained from physical examination.
- Stroke or disorders of the central and peripheral nervous system.
- Patients with metabolic diseases such as diabetes mellitus and heart disease or other autoimmune diseases based on medical records in unstable condition with pre-prandial capillary blood glucose ≠ 80-130 mg/dL or 1-2 hours post-prandial capillary blood glucose ≠ <180 mg/dL, systolic blood pressure ≠ 90-140 mmHg and diastolic blood pressure ≠ 60-90 mmHg.
- Pain durin loaded knee extension exercise greatetr than 3 on the Visual Analogue Scale (VAS)
Trial locations and contacts
1 site in 1 country.
Indonesia1 site
Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo General Hospital
Jakarta, DKI Jakarta, 10430
About this study
Official title: Comparative Effectiveness of N-K Table Load Angles at 0° and 50° on Quadriceps Femoris Maximum Voluntary Contraction in Patients With Knee Osteoarthritis
Knee osteoarthritis (OA) is a common degenerative joint disease that leads to pain, reduced mobility, and functional limitation. Quadriceps femoris weakness plays a significant role in disease progression and disability. Isotonic strengthening using the N-K Table allows adjustment of load angles to optimize muscle activation; however, the effect of different load angles on quadriceps activation in patients with knee osteoarthritis remains unclear.
This study aims to compare quadriceps femoris activation at 0° and 50° N-K Table load angles in patients with knee osteoarthritis using surface electromyography (sEMG). A randomized cross-over experimental design is applied to determine whether adjusting the load angle improves maximum voluntary contraction (MVC) during isotonic knee extension exercise.
Read the detailed description
Knee osteoarthritis (OA) is the most prevalent joint disease and a leading cause of disability among older adults. The progressive degeneration of articular cartilage and structural remodeling of the joint result in chronic pain, stiffness, and limited movement. Among the factors contributing to disability, quadriceps femoris weakness plays a central role by impairing knee stability and shock absorption during gait.
Isotonic strengthening exercises using the N-K Table provide a controlled method to restore quadriceps strength while minimizing excessive joint loading. The N-K Table allows adjustment of the load arm angle, which may better align external resistance with the physiological torque profile of the knee extensors, including the vastus medialis, vastus lateralis, and rectus femoris. Although previous studies in healthy adults suggest that higher load angles may optimize torque production, the specific effect in patients with knee osteoarthritis has not been clearly established.
This study employed a randomized cross-over experimental design. A total of 43 female participants aged 50-65 years with unilateral or bilateral knee osteoarthritis (Kellgren-Lawrence grade 2-3) were enrolled. Each participant performed isotonic knee extension exercises at 0° and 50° N-K Table load angles in random order. Exercise intensity was set at 75% of the individual ten-repetition maximum (10RM). Surface electromyography (sEMG) was used to measure maximum voluntary contraction (MVC) of the vastus medialis, vastus lateralis, and rectus femoris. The primary outcome was the difference in MVC between the two load angles. Secondary variables included age, body mass index, and physical activity level.
The study was conducted at the Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia, between January and June 2024. Ethical approval was obtained from the institutional ethics committee, and all participants provided written informed consent prior to participation.
- Conditions
- Knee Osteoarthritis, Osteearthritis
- Being tested
- Isotonic Quadriceps Exercise Using NK Table
- Keywords
- Knee Osteoarthritis, Quadriceps Femoris, Isotonic Muscle Strengthening, Maximum Voluntary Contraction, Surface Electromyography
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Isotonic Quadriceps Exercise Using NK TableOther
Isotonic knee extension exercise performed using the N-K Table device at specified load angles (0° and 50°) with resistance set at 75% of 10RM.
| Study group | Role | What they receive |
|---|---|---|
| 0° Load Angle NK Table | Experimental | Participants performed isotonic knee extension exercise using the N-K Table adjusted to a 0° load angle. Exercise intensity was set at 75% of the individual 10-repetition maximum (10RM). Each participant performed controlled knee extension movements from 90° flexion to near full extension. At each load angle, three maximal voluntary contractions were recorded with 3-second rest intervals between trials. Surface electromyography (sEMG) was used to measure maximum voluntary contraction (MVC) of the vastus medialis, vastus lateralis, and rectus femoris muscles. Receives: Other: Isotonic Quadriceps Exercise Using NK Table |
| 50° Load Angle NK Table | Experimental | Participants performed isotonic knee extension exercise using the N-K Table adjusted to a 50° load angle. Exercise intensity was set at 75% of the individual 10-repetition maximum (10RM). Each participant performed controlled knee extension movements from 90° flexion to near full extension. At each load angle, three maximal voluntary contractions were recorded with 3-second rest intervals between trials. Surface electromyography (sEMG) was used to measure maximum voluntary contraction (MVC) of the vastus medialis, vastus lateralis, and rectus femoris muscles. Receives: Other: Isotonic Quadriceps Exercise Using NK Table |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maximum Voluntary Contraction (MVC) of Quadriceps Femoris Muscles
Maximum voluntary contraction (MVC) of the quadriceps femoris muscles (vastus medialis, rectus femoris, and vastus lateralis) measured using surface electromyography (sEMG) during isotonic knee extension exercise performed on the N-K Table at 0° and 50° load angles. MVC is defined as the highest sEMG amplitude recorded from three maximal voluntary contraction trials for each muscle.
Measured: Day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2026
- Study start20 Jan 2024
- Primary completion5 Jun 2024
- Study completion25 May 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Knee OsteoarthritisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study uses a randomized cross-over design in which all participants perform isotonic knee extension exercises at two N-K Table load angles (0° and 50°) in random order. Each participant serves as their own control, and sufficient rest intervals are provided between testing conditions to minimize fatigue effects.
- Masking
- None (open label)
- Enrolment
- 43 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universitas Indonesia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Nurul Sardwiyanti, Universitas Indonesia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07456254
- Sponsor's protocol ID
- 1207/UN2.F1/ETIK/PPM.0002/2023
- Status last verified
- Mar 2026
- First submitted
- 25 Feb 2026
- Last updated
- 6 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: There is no plan to share individual participant data.
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparative Effectiveness of N-K Table Load Angles at 0° and 50° on Quadriceps Femoris Maximum Voluntary Contraction in Patients With Knee Osteoarthritis
- ClinicalTrials.gov ID
- NCT07456254
- Acronym / sponsor ID
- 1207/UN2.F1/ETIK/PPM.0002/2023
- Conditions
- Knee Osteoarthritis, Osteearthritis
- Keywords
- Knee Osteoarthritis, Quadriceps Femoris, Isotonic Muscle Strengthening, Maximum Voluntary Contraction, Surface Electromyography
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 43 participants (actual)
- Lead sponsor
- Universitas IndonesiaUniversity, hospital or other
- Study start
- 20 Jan 2024 (actual)
- Primary completion
- 5 Jun 2024 (actual)
- Study completion
- 25 May 2025 (actual)
- First posted
- 6 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Knee osteoarthritis (OA) is a common degenerative joint disease that leads to pain, reduced mobility, and functional limitation. Quadriceps femoris weakness plays a significant role in disease progression and disability. Isotonic strengthening using the N-K Table allows adjustment of load angles to optimize muscle activation; however, the effect of different load angles on quadriceps activation in patients with knee osteoarthritis remains unclear.
This study aims to compare quadriceps femoris activation at 0° and 50° N-K Table load angles in patients with knee osteoarthritis using surface electromyography (sEMG). A randomized cross-over experimental design is applied to determine whether adjusting the load angle improves maximum voluntary contraction (MVC) during isotonic knee extension exercise.
Detailed description
Knee osteoarthritis (OA) is the most prevalent joint disease and a leading cause of disability among older adults. The progressive degeneration of articular cartilage and structural remodeling of the joint result in chronic pain, stiffness, and limited movement. Among the factors contributing to disability, quadriceps femoris weakness plays a central role by impairing knee stability and shock absorption during gait.
Isotonic strengthening exercises using the N-K Table provide a controlled method to restore quadriceps strength while minimizing excessive joint loading. The N-K Table allows adjustment of the load arm angle, which may better align external resistance with the physiological torque profile of the knee extensors, including the vastus medialis, vastus lateralis, and rectus femoris. Although previous studies in healthy adults suggest that higher load angles may optimize torque production, the specific effect in patients with knee osteoarthritis has not been clearly established.
This study employed a randomized cross-over experimental design. A total of 43 female participants aged 50-65 years with unilateral or bilateral knee osteoarthritis (Kellgren-Lawrence grade 2-3) were enrolled. Each participant performed isotonic knee extension exercises at 0° and 50° N-K Table load angles in random order. Exercise intensity was set at 75% of the individual ten-repetition maximum (10RM). Surface electromyography (sEMG) was used to measure maximum voluntary contraction (MVC) of the vastus medialis, vastus lateralis, and rectus femoris. The primary outcome was the difference in MVC between the two load angles. Secondary variables included age, body mass index, and physical activity level.
The study was conducted at the Department of Physical Medicine and Rehabilitation, Dr. Cipto Mangunkusumo National General Hospital, Jakarta, Indonesia, between January and June 2024. Ethical approval was obtained from the institutional ethics committee, and all participants provided written informed consent prior to participation.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This study uses a randomized cross-over design in which all participants perform isotonic knee extension exercises at two N-K Table load angles (0° and 50°) in random order. Each participant serves as their own control, and sufficient rest intervals are provided between testing conditions to minimize fatigue effects.
| Arm | Type | Receives |
|---|---|---|
| 0° Load Angle NK Table | Experimental | Other: Isotonic Quadriceps Exercise Using NK TableParticipants performed isotonic knee extension exercise using the N-K Table adjusted to a 0° load angle. Exercise intensity was set at 75% of the individual 10-repetition maximum (10RM). Each participant performed controlled knee extension movements from 90° flexion to near full extension. At each load angle, three maximal voluntary contractions were recorded with 3-second rest intervals between trials. Surface electromyography (sEMG) was used to measure maximum voluntary contraction (MVC) of the vastus medialis, vastus lateralis, and rectus femoris muscles. |
| 50° Load Angle NK Table | Experimental | Other: Isotonic Quadriceps Exercise Using NK TableParticipants performed isotonic knee extension exercise using the N-K Table adjusted to a 50° load angle. Exercise intensity was set at 75% of the individual 10-repetition maximum (10RM). Each participant performed controlled knee extension movements from 90° flexion to near full extension. At each load angle, three maximal voluntary contractions were recorded with 3-second rest intervals between trials. Surface electromyography (sEMG) was used to measure maximum voluntary contraction (MVC) of the vastus medialis, vastus lateralis, and rectus femoris muscles. |
Who may qualify
- Ages
- 50 to 65 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Diagnosed with unilateral or bilateral knee osteoarthritis (OA), grade 2 or 3, in the subacute or chronic phase based on the criteria of the American College of Rheumatology (ACR) and Kellgren-Lawrence classification.
- Female, aged 50-65 years, based on ACR diagnostic criteria.
- Knee flexion-extension range of motion of at least 0-120 degrees.
- Normal cognitive function as assessed using the Montreal Cognitive Assessment Indonesia Version (MoCA-INA) (score ≥26-30)
Key exclusion criteria (7 listed)
- Knee joint instability due to ligament laxity in the cruciate or collateral ligaments obtained from physical examination (valgus/varus test and anterior/posterior drawer test) or previous supporting examination.
- Presence of deformity in the form of genu varus, genu valgus, or genu recurvatum (Q angle 12-20°).
- History of knee injury (fracture, ligament rupture, or meniscus) or having undergone knee surgery.
- Pain or instability of the ankle joint obtained from physical examination.
- Stroke or disorders of the central and peripheral nervous system.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Isotonic Quadriceps Exercise Using NK TableIsotonic knee extension exercise performed using the N-K Table device at specified load angles (0° and 50°) with resistance set at 75% of 10RM. | Other | 0° Load Angle NK Table, 50° Load Angle NK Table |
Primary outcome
Maximum Voluntary Contraction (MVC) of Quadriceps Femoris Muscles
Time frame: Day 1
Maximum voluntary contraction (MVC) of the quadriceps femoris muscles (vastus medialis, rectus femoris, and vastus lateralis) measured using surface electromyography (sEMG) during isotonic knee extension exercise performed on the N-K Table at 0° and 50° load angles. MVC is defined as the highest sEMG amplitude recorded from three maximal voluntary contraction trials for each muscle.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2026.
- Individual participant dataSharing planned: No. There is no plan to share individual participant data.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Isotonic Quadriceps Exercise Using NK Table in people with Knee Osteoarthritis and Osteearthritis, run by Universitas Indonesia at 1 site in Indonesia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Indonesia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Maximum Voluntary Contraction (MVC) of Quadriceps Femoris Muscles (time frame: Day 1). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Mar 2026.