Knee OsteoarthritisNCT07698418
Effect of Inspiratory Muscle Training on Knee Osteoarthritis Pain
A study testing Inspiratory muscle training in people with Knee Osteoarthritis and Knee Osteoarthritis (Knee OA), run by The Hong Kong Polytechnic University.
Trial summary
Knee osteoarthritis (KOA) is a common joint disease that causes chronic pain and limits daily activities. Current treatments, such as painkillers or surgery, have limitations like side effects or high costs. Read more about this study
- Who is it for?
- Ages 55 to 80 years
- Conditions the study is for
- Knee Osteoarthritis, Knee Osteoarthritis (Knee OA)
- What is being tested?
- Inspiratory muscle training
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 80 participants
- Where
- No sites listed yet
- Study dates
- 1 Sep 2026to 1 Sep 2030
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 55 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged 55 years or older.
- Knee osteoarthritis (Kellgren-Lawrence grade ≥ 2).
- Knee pain (Visual Analogue Scale, VAS ≥ 3) on the most days in the past month.
- Able to walk independently without assitive devices.
Who cannot join
- History of knee replacement surgery, meniscus surgery, or ligament surgery.
- Received corticosteroid injection within the previous three weeks.
- Diagnosed with rheumatoid arthritis.
- Unstable angina, recent myocardial infarction, uncontrolled cardiac arrhythmia, or severe heart failure.
- History of stroke.
- Currently receiving steroid therapy, hormonal therapy, or cancer chemotherapy.
- Pneumothorax, pulmonary bullae, lung surgery within the past 12 months, unstable asthma, or severe dyspnea at rest.
- Unable to understand the study procedures and potential risks.
About this study
Official title: Effect of Inspiratory Muscle Training on Pain in Patients With Knee Osteoarthritis: A Randomized Controlled Trial
Knee osteoarthritis (KOA) is a common joint disease that causes chronic pain and limits daily activities. Current treatments, such as painkillers or surgery, have limitations like side effects or high costs. This study will test whether a safe, non-drug intervention-inspiratory muscle training (breathing exercises against resistance)-can reduce knee pain in people with KOA. The training may work by lowering inflammation and improving the brain's modulation of pain.
Eighty patients aged ≥55 years with confirmed KOA and frequent knee pain will be enrolled. Participants will be randomly assigned to either an 8-week inspiratory muscle training program (5 sessions per week, with gradually increasing resistance) or a sham (very low resistance) training program. Neither the patients nor the researchers assessing the outcomes will know who is in which group.
Read more
The main outcome is change in knee pain measured by a visual analog scale (VAS). Secondary outcomes include blood markers of inflammation (TNF-α, IL-6, IL1β), physical function, the Knee injury and Osteoarthritis Outcome Score (KOOS), inspiratory muscle strength, activity level, sleep quality, and quality of life. To explore underlying mechanisms, outcomes included heart rate variability (HRV) as an indicator of autonomic nervous system function, and brain functional connectivity in the prefrontal cortex using functional near-infrared spectroscopy (fNIRS) are collected. These mechanistic assessments will be performed at baseline and at the end of 8-week intervention. Additional follow-up assessments for clinical outcomes will be done at 3 and 6 months after the training ends. Any side effects or adverse events will be recorded.
This study will provide high-quality evidence on whether inspiratory muscle training is an effective and safe complementary treatment for knee pain in people with knee OA, and will offer new insights into the mechanisms underlying its analgesic effects.
- Conditions
- Knee Osteoarthritis, Knee Osteoarthritis (Knee OA)
- Being tested
- Inspiratory muscle training, Sham inspiratory muscle training
- Keywords
- Knee Osteoarthritis, Inspiratory Muscle Training, Chronic Pain
- Medical subject headings
- Osteoarthritis, Knee, Chronic Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Inspiratory muscle trainingOther
Also called Respiratory muscle training
Participants will perform home-based inspiratory muscle training using a threshold-loading device (POWERbreathe Medic Plus). Training is conducted 5 times per week for 8 weeks. The initial inspiratory load is set at 50% of the individual's maximum inspiratory pressure (MIP), measured weekly at the study site. The load is progressively increased to 80% MIP over the first 4 weeks and maintained at 80% MIP for the remaining 4 weeks. Each session consists of 40-60 breaths. Adherence is monitored via an electronic training log and weekly on-site visits. This protocol is individualized, progressive, and home-based, distinguishing it from fixed-load or supervised-only breathing interventions.
Sham inspiratory muscle trainingOther
Participants will perform home-based inspiratory muscle training using a threshold-loading device (POWERbreathe Medic Plus). Training is conducted 5 times per week for 8 weeks. The initial inspiratory load is set at 10% of the individual's maximum inspiratory pressure (MIP), measured weekly at the study site. The load is maintained 10% MIP over 8 weeks. Each session consists of 40-60 breaths. Adherence is monitored via an electronic training log and weekly on-site visits.
| Study group | Role | What they receive |
|---|---|---|
| Inspiratory Muscle Training | Experimental | 5 sessions/week for 8 weeks. Load starts at 50% MIP for 40 reps, increases to 80% MIP for 60 reps from week 5, then adjusted weekly to 80% of updated MIP. Device: threshold inspiratory muscle trainer. Receives: Other: Inspiratory muscle training |
| Sham Inspiratory Muscle Training | Sham comparator | Participants perform sham inspiratory muscle training with the same frequency and duration as the experimental group, but the inspiratory load is fixed at 10% of maximal inspiratory pressure (MIP) and does not progress. All other procedures (weekly MIP measurement for sham load adjustment) are identical to maintain blinding. Receives: Other: Sham inspiratory muscle training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual analogue scale
Self-rated pain intensity of knee (0-100), "0" indicate no pain, "100" indicate worst pain.
Measured: Baseline, week 8, 3-month after intervention, 6-month after intervention
Secondary outcomes (10)
The Knee injury and Osteoarthritis Outcome Score
Patient-reported outcomes in pain, symptoms, daily living activities, sports and recreational activities, and quality of life, with the score of each subscale ranging from 0-100, where higher scores indicate worse conditions.
Measured: Baseline, week 8, 3-month after intervention, 6-month after intervention
Serum levels of inflammatory markers
Systemic inflammation
Measured: Baseline, up to week 8
Heart rate variability
Vagus nerve activity
Measured: Baseline, up to week 8
Prefrontal cortex activity
Functional near-infrared spectroscopy is used to assess prefrontal cortex activity
Measured: Baseline, up to week 8
40-meter walk test
Physical function
Measured: Baseline, up to week 8
30-sec chair stand test
Physical function
Measured: Baseline, up to week 8
Physical Activity Scales for the Elderly
Total scores range from 0-793, where the higher scores indicate a higher level of physical activity.
Measured: Baseline, week 8, 3-month after intervention, 6-month after intervention
Pittsburgh Sleep Quality Index
Total scores range from 0-21, '0' indicating no difficulty and '21' indicating severe difficulties in all areas.
Measured: Baseline, week 8, 3-month after intervention, 6-month after intervention
12-Item Short Form Health Survey
Total scores range from 0-100, where the higher scores indicate better physical and mental health function.
Measured: Baseline, week 8, 3-month after intervention, 6-month after intervention
Maximal inspiratory pressure
Inspiratory muscle strength
Measured: Baseline, up to week 8
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Jul 2026
- Study start1 Sep 2026 (estimated)
- Primary completion1 Sep 2030 (estimated)
- Study completion1 Sep 2030 (estimated)
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.
- More trials run by The Hong Kong Polytechnic UniversityThe sponsor's other registered studies.
- 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
- Parallel groups
- Model description
- Two parallel arms: experimental (inspiratory muscle training) and control (sham inspiratory muscle training), with a 1:1 allocation ratio.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The Hong Kong Polytechnic University
- Sponsor type
- University, hospital or other
- Collaborators
- Zunyi Medical College
- Responsible party
- Principal investigator, SU Shan, The Hong Kong Polytechnic University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07698418
- Sponsor's protocol ID
- ZHSC-1-(2026)014
- Status last verified
- Apr 2026
- First submitted
- 7 Jul 2026
- Last updated
- 16 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Inspiratory Muscle Training on Pain in Patients With Knee Osteoarthritis: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07698418
- Acronym / sponsor ID
- ZHSC-1-(2026)014
- Conditions
- Knee Osteoarthritis, Knee Osteoarthritis (Knee OA)
- Keywords
- Knee Osteoarthritis, Inspiratory Muscle Training, Chronic Pain
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- The Hong Kong Polytechnic UniversityUniversity, hospital or other
- Collaborators
- Zunyi Medical College
- Study start
- 1 Sep 2026 (estimated)
- Primary completion
- 1 Sep 2030 (estimated)
- Study completion
- 1 Sep 2030 (estimated)
- First posted
- 13 Jul 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 (KOA) is a common joint disease that causes chronic pain and limits daily activities. Current treatments, such as painkillers or surgery, have limitations like side effects or high costs. This study will test whether a safe, non-drug intervention-inspiratory muscle training (breathing exercises against resistance)-can reduce knee pain in people with KOA. The training may work by lowering inflammation and improving the brain's modulation of pain.
Eighty patients aged ≥55 years with confirmed KOA and frequent knee pain will be enrolled. Participants will be randomly assigned to either an 8-week inspiratory muscle training program (5 sessions per week, with gradually increasing resistance) or a sham (very low resistance) training program. Neither the patients nor the researchers assessing the outcomes will know who is in which group.
The main outcome is change in knee pain measured by a visual analog scale (VAS). Secondary outcomes include blood markers of inflammation (TNF-α, IL-6, IL1β), physical function, the Knee injury and Osteoarthritis Outcome Score (KOOS), inspiratory muscle strength, activity level, sleep quality, and quality of life. To explore underlying mechanisms, outcomes included heart rate variability (HRV) as an indicator of autonomic nervous system function, and brain functional connectivity in the prefrontal cortex using functional near-infrared spectroscopy (fNIRS) are collected. These mechanistic assessments will be performed at baseline and at the end of 8-week intervention. Additional follow-up assessments for clinical outcomes will be done at 3 and 6 months after the training ends. Any side effects or adverse events will be recorded.
This study will provide high-quality evidence on whether inspiratory muscle training is an effective and safe complementary treatment for knee pain in people with knee OA, and will offer new insights into the mechanisms underlying its analgesic effects.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Two parallel arms: experimental (inspiratory muscle training) and control (sham inspiratory muscle training), with a 1:1 allocation ratio.
| Arm | Type | Receives |
|---|---|---|
| Inspiratory Muscle Training | Experimental | Other: Inspiratory muscle training5 sessions/week for 8 weeks. Load starts at 50% MIP for 40 reps, increases to 80% MIP for 60 reps from week 5, then adjusted weekly to 80% of updated MIP. Device: threshold inspiratory muscle trainer. |
| Sham Inspiratory Muscle Training | Sham comparator | Other: Sham inspiratory muscle trainingParticipants perform sham inspiratory muscle training with the same frequency and duration as the experimental group, but the inspiratory load is fixed at 10% of maximal inspiratory pressure (MIP) and does not progress. All other procedures (weekly MIP measurement for sham load adjustment) are identical to maintain blinding. |
Who may qualify
- Ages
- 55 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Aged 55 years or older.
- Knee osteoarthritis (Kellgren-Lawrence grade ≥ 2).
- Knee pain (Visual Analogue Scale, VAS ≥ 3) on the most days in the past month.
- Able to walk independently without assitive devices.
Key exclusion criteria (8 listed)
- History of knee replacement surgery, meniscus surgery, or ligament surgery.
- Received corticosteroid injection within the previous three weeks.
- Diagnosed with rheumatoid arthritis.
- Unstable angina, recent myocardial infarction, uncontrolled cardiac arrhythmia, or severe heart failure.
- History of stroke.
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 |
|---|---|---|
| Inspiratory muscle trainingAlso: Respiratory muscle trainingParticipants will perform home-based inspiratory muscle training using a threshold-loading device (POWERbreathe Medic Plus). Training is conducted 5 times per week for 8 weeks. The initial inspiratory load is set at 50% of the individual's maximum inspiratory pressure (MIP), measured weekly at the study site. The load is progressively increased to 80% MIP over the first 4 weeks and maintained at 80% MIP for the remaining 4 weeks. Each session consists of 40-60 breaths. Adherence is monitored via an electronic training log and weekly on-site visits. This protocol is individualized, progressive, and home-based, distinguishing it from fixed-load or supervised-only breathing interventions. | Other | Inspiratory Muscle Training |
| Sham inspiratory muscle trainingParticipants will perform home-based inspiratory muscle training using a threshold-loading device (POWERbreathe Medic Plus). Training is conducted 5 times per week for 8 weeks. The initial inspiratory load is set at 10% of the individual's maximum inspiratory pressure (MIP), measured weekly at the study site. The load is maintained 10% MIP over 8 weeks. Each session consists of 40-60 breaths. Adherence is monitored via an electronic training log and weekly on-site visits. | Other | Sham Inspiratory Muscle Training |
Primary outcome
Visual analogue scale
Time frame: Baseline, week 8, 3-month after intervention, 6-month after intervention
Self-rated pain intensity of knee (0-100), "0" indicate no pain, "100" indicate worst pain.
10 secondary outcomes
The Knee injury and Osteoarthritis Outcome Score
Time frame: Baseline, week 8, 3-month after intervention, 6-month after intervention
Serum levels of inflammatory markers
Time frame: Baseline, up to week 8
Heart rate variability
Time frame: Baseline, up to week 8
Prefrontal cortex activity
Time frame: Baseline, up to week 8
40-meter walk test
Time frame: Baseline, up to week 8
30-sec chair stand test
Time frame: Baseline, up to week 8
Physical Activity Scales for the Elderly
Time frame: Baseline, week 8, 3-month after intervention, 6-month after intervention
Pittsburgh Sleep Quality Index
Time frame: Baseline, week 8, 3-month after intervention, 6-month after intervention
12-Item Short Form Health Survey
Time frame: Baseline, week 8, 3-month after intervention, 6-month after intervention
Maximal inspiratory pressure
Time frame: Baseline, up to week 8
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jul 2026.
Related trials for Knee Osteoarthritis
Not yet recruiting
Holistic Healing for Knee Osteoarthritis
Knee Osteoarthritis (Knee OA)
Recruiting
Effect of Anti-inflammatory Diet in Osteoarthritis
Osteoarthritis, Knee
Active, not recruitingPhase 2/3
Single vs Triple Hyaluronic Acid in Knee Osteoarthritis
Osteoarthritis, Knee
Not yet recruiting
The Feasibility of a Virtual/Home-based OA Treatment Program in Older Adults With OA and Multimorbidity
Osteoarthritis of the Knee
RecruitingObservational study
Exploring Factors Linked to Worsening Over Time in People With Early-stage Knee Osteoarthritis and Those With Prior Proven Acute Knee Injury.
Knee Osteoarthritis
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.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A study testing Inspiratory muscle training in people with Knee Osteoarthritis and Knee Osteoarthritis (Knee OA), run by The Hong Kong Polytechnic University.
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 8 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: opening soon, as of the sponsor's last update on 16 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. 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?
This study is still under way. Results are not available in the source record yet.
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?
Visual analogue scale (time frame: Baseline, week 8, 3-month after intervention, 6-month after intervention). 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 16 Jul 2026.