Anterior Knee PainETFRPPRRCTNCT06808386
Effects of Training Frequency on Patellofemoral Pain Rehabilitation.
A study testing Strengthening 2 times per week and Strengthening 3 times per week in people with Anterior Knee Pain, run by University of Nove de Julho at 1 site in Brazil.
Trial summary
This clinical trial aims to determine the optimal frequency of exercise therapy for improving pain, function, and quality of life in participants with patellofemoral pain. The main questions it aims to answer are: Does exercising twice a week provide the same benefits as exercising three times a week for individuals… Read more about this study
- Who is it for?
- Ages 18 to 40 years
- Conditions the study is for
- Anterior Knee Pain
- What is being tested?
- Strengthening 2 times per week and Strengthening 3 times per week
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 84 participants
- Where
- 1 siteBrazil
- Study dates
- 24 Feb 2025to 21 Dec 2026
- 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 18 to 40 years
- All sexes
- No healthy volunteers
- Adult
Inclusion Criteria: This study will include physically active individuals of both sexes, aged between 18 and 40 years, who have been experiencing patellofemoral pain and anterior knee pain for at least three months. Participants must have a score of at least three points on the Visual Analog Scale during any of the following activities: running, squatting, sitting for long periods with the knee bent, and climbing or descending stairs. Selection will be based on responses provided in the International Physical Activity Questionnaire.
Exclusion Criteria: Exclusion criteria include the following: a history of lower limb or spine surgery, patellar dislocation, anterior knee pain resulting from trauma, coexisting conditions in the knee joint such as meniscal and/or ligament injuries, lateral and/or posterior knee pain, cardiovascular issues or locomotion disorders that could impact the assessment, pregnancy, and a limb length discrepancy greater than 1 cm.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Comparison of the Effects of Different Training Frequencies on the Rehabilitation of Individuals with Patellofemoral Pain: a Randomized Clinical Trial
This clinical trial aims to determine the optimal frequency of exercise therapy for improving pain, function, and quality of life in participants with patellofemoral pain. The main questions it aims to answer are:
Does exercising twice a week provide the same benefits as exercising three times a week for individuals with patellofemoral pain? What are the optimal dosage, volume, and weekly exercise frequency for treating patellofemoral pain?
Read more
The investigators will compare two groups of participants: one group of participants receiving exercise therapy twice a week and another group receiving exercise therapy three times a week. Both groups will follow the same exercise protocol targeting the muscles of the hip and knee joints.
Participants:
84 volunteers (both male and female) with patellofemoral pain Physically active individuals aged between 18 and 40 years
Interventions:
Participants will be randomly assigned to one of two groups Both groups will perform the same exercises for hip and knee muscle strengthening Group A will exercise three times per week Group B will exercise two times per week The intervention will last for six consecutive weeks
Assessments: Participants will be evaluated at the following time points:
Before the intervention After the 4th and 6th week of intervention 6 months and 1 year after the end of the intervention
The primary Outcome Measure will be pain intensity.
Secondary Outcome Measure:
Anterior knee pain during daily activities Kinesiophobia Pain-related self-efficacy Chronic pain-related self-efficacy Catastrophizing Muscle strength 3D Movement analysis
Data Analysis:
The investigators will use an intention-to-treat analysis, which means that all participants will be included in the study, regardless of whether they completed the treatment as planned.
Appropriate statistical tests will be used to compare differences within and between the two groups, considering the time points and group factors.
A 5% significance level will be adopted, which means there is a 5% chance that the results are due to random variation rather than the treatment effect.
Read the detailed description
This clinical trial aims to investigate the optimal frequency of exercise therapy for individuals with patellofemoral pain. Current evidence supports exercise therapy as the first line of treatment for pain relief, improved function, and enhanced quality of life in individuals with patellofemoral pain. However, the most recent consensus on patellofemoral pain highlighted a gap in the ideal dosage, volume, and weekly exercise frequency for treating these individuals.
To address this gap, this study will compare two groups of individuals with patellofemoral pain who will undergo the same exercise program targeting the muscles of the hip and knee joints but with different frequencies. One group will perform the exercises twice weekly, while the other will do so thrice.
This randomized, controlled, double-blind clinical trial will recruit 84 physically active participants of both sexes, aged 18 to 40 years, who experience patellofemoral pain. Participants will be randomly and secretly allocated to one of two groups. Group A will perform the exercise protocol three times per week, and Group B will perform the same protocol twice weekly.
The intervention will last for six consecutive weeks. Participants will be evaluated at multiple time points: before the intervention, after the 4th and 6th week of intervention, and at 6 months and 1 year post-intervention. The evaluations will include pain intensity as a primary outcome, anterior knee pain during daily activities, kinesiophobia, pain-related self-efficacy, chronic pain-related self-efficacy, catastrophizing, muscle strength and 3d movement analysis as a secondary analysis.
The data analysis will follow the intention-to-treat principle, meaning all participants will be included in the analysis regardless of whether they completed the treatment as planned. Normality tests will be conducted to verify data distribution, and appropriate statistical tests will be used to compare differences within and between the two groups, considering time and group factors. A 5% level of significance will be adopted for statistical comparisons.
- Conditions
- Anterior Knee Pain
- Being tested
- Strengthening 2 times per week, Strengthening 3 times per week
- Keywords
- Patellofemoral Pain, Exercise Therapy, Dose-Response, Musculoskeletal Pain
- Medical subject headings
- Patellofemoral Pain Syndrome, Musculoskeletal Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Strengthening 2 times per weekOther
This group will consist of participants with patellofemoral pain and will receive treatment twice a week.
Strengthening 3 times per weekOther
This group will consist of participants with patellofemoral pain and will receive treatment thrice a week.
| Study group | Role | What they receive |
|---|---|---|
| Strengthening 2 times per week | Experimental | This group will consist of participants with patellofemoral pain and will receive treatment twice a week. Receives: Other: Strengthening 2 times per week |
| Strengthening 3 times per week | Other | This group will consist of participants with patellofemoral pain and will receive treatment twice a week. Receives: Other: Strengthening 3 times per week |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pain intensity
Visual Analog Pain Scale: This scale aims to quantify the intensity of pain experienced by the patient. The scale consists of 11 points, with a score classification from 0 to 10. A score of 0 represents "no pain at all", and 10 means "the worst pain possible". Patients will be asked to rate their anterior knee pain intensity levels based on the past fifteen days. The minimum clinically important difference for improvement will be a decrease of 1 point on the scale.
Measured: Evaluations will occur at five time frames: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Secondary outcomes (8)
Anterior Knee Pain Scale
This is a specific questionnaire for anterior knee pain, consisting of 13 items categorised into different knee function levels. Each item is answered, and the total result is added to a global index with a maximum score of 100 points, representing "no deficit," and a minimum score of zero, representing "the greatest possible deficit". The minimum clinically significant difference for improvement will be a reduction of 2 points on the scale.
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Tampa Scale for Kinesiophobia
This psychometric questionnaire quantifies the fear associated with pain. It consists of 17 questions, each scored on a four-point Likert scale. The total score ranges from 17 to 68 points, with values above 37 points indicating a higher fear associated with movement.
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Pain Self-Efficacy Questionnaire
This psychometric questionnaire quantifies the patient's confidence in performing activities despite pain. It consists of ten questions, each scored on a six-point Likert scale. The total score ranges from 10 to 60 points, with higher values indicating greater patient confidence regardless of pain.
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Chronic Pain Self-Efficacy Scale
This psychometric scale consists of 22 items that measure the confidence of patients with chronic pain in performing specific tasks in different domains: pain control, physical function, and symptom control. Each item is scored on a Likert scale ranging from ten to 100 points, with higher values indicating greater patient confidence regardless of pain.
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Pain Catastrophizing Scale
This questionnaire consists of 13 statements that contain various thoughts and feelings a person may have when experiencing pain. The items are divided into rumination, magnification, and helplessness, each scoring on a 5-point scale. Participants are asked to rate how often they experience these feelings, from 0 (not at all) to 4 (always). The total score ranges from 0 to 52 points, with higher scores indicating greater pain catastrophizing.
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Global Perceived Effect Scale
The perception of the global effect of the treatment by the research participant will be assessed using the Global Perceived Effect Scale. The Global Perceived Effect Scale is a direct scale, validated for Brazilian Portuguese, with good psychometric properties, which aims to assess self-perception of the intervention performed. Participants will be asked: "Compared to the beginning of the treatment, how would you describe your knee(s) today?" Participants will then mark their response on an 11-point scale, ranging from -5 (worse than before treatment), 0 (neutral), to +5 (better than before treatment). The minimum clinically important difference for improvement will be 2.5 points on the scale (Freitas et al., 2019; Bobos et al., 2020).
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Maximum isometric muscle strength
Maximum isometric muscle strength measure maximum isometric muscle strength using a manual dynamometer.
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment.
Three-dimensional movement analysis
Three-DimensionalMovement Analysis is a comprehensive technique used to evaluate the movement and forces involved in body motions.
Kinematic analysis focuses on the motion of body segments and joints in three dimensions, capturing data on their positions, velocities, and accelerations.
Kinetic analysis examines the forces that cause these movements, such as muscle forces, ground reaction forces, and joint moments.
By combining both kinematic and kinetic data, this analysis provides a detailed understanding of the biomechanics of human motion.
Measured: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2025
- Study start24 Feb 2025 (estimated)
- Primary completion30 Nov 2026 (estimated)
- Study completion21 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Anterior Knee PainStudies 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
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 84 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Nove de Julho
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Paulo Roberto Garcia Lucareli, University of Nove de Julho
- Investigators
- PAULO RG LUCARELI, PhD, Study chair, Nove de Julho University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06808386
- Sponsor's protocol ID
- 84694624.0.0000.5511
- Acronym
- ETFRPPRRCT
- Status last verified
- Feb 2025
- First submitted
- 28 Jan 2025
- Last updated
- 5 Feb 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of the Effects of Different Training Frequencies on the Rehabilitation of Individuals with Patellofemoral Pain: a Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT06808386
- Acronym / sponsor ID
- ETFRPPRRCT / 84694624.0.0000.5511
- Conditions
- Anterior Knee Pain
- Keywords
- Patellofemoral Pain, Exercise Therapy, Dose-Response, Musculoskeletal Pain
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 84 participants (estimated)
- Lead sponsor
- University of Nove de JulhoUniversity, hospital or other
- Study start
- 24 Feb 2025 (estimated)
- Primary completion
- 30 Nov 2026 (estimated)
- Study completion
- 21 Dec 2026 (estimated)
- First posted
- 5 Feb 2025 (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.
This clinical trial aims to determine the optimal frequency of exercise therapy for improving pain, function, and quality of life in participants with patellofemoral pain. The main questions it aims to answer are:
Does exercising twice a week provide the same benefits as exercising three times a week for individuals with patellofemoral pain? What are the optimal dosage, volume, and weekly exercise frequency for treating patellofemoral pain?
The investigators will compare two groups of participants: one group of participants receiving exercise therapy twice a week and another group receiving exercise therapy three times a week. Both groups will follow the same exercise protocol targeting the muscles of the hip and knee joints.
Participants:
84 volunteers (both male and female) with patellofemoral pain Physically active individuals aged between 18 and 40 years
Interventions:
Participants will be randomly assigned to one of two groups Both groups will perform the same exercises for hip and knee muscle strengthening Group A will exercise three times per week Group B will exercise two times per week The intervention will last for six consecutive weeks
Assessments: Participants will be evaluated at the following time points:
Before the intervention After the 4th and 6th week of intervention 6 months and 1 year after the end of the intervention
The primary Outcome Measure will be pain intensity.
Secondary Outcome Measure:
Anterior knee pain during daily activities Kinesiophobia Pain-related self-efficacy Chronic pain-related self-efficacy Catastrophizing Muscle strength 3D Movement analysis
Data Analysis:
The investigators will use an intention-to-treat analysis, which means that all participants will be included in the study, regardless of whether they completed the treatment as planned.
Appropriate statistical tests will be used to compare differences within and between the two groups, considering the time points and group factors.
A 5% significance level will be adopted, which means there is a 5% chance that the results are due to random variation rather than the treatment effect.
Detailed description
This clinical trial aims to investigate the optimal frequency of exercise therapy for individuals with patellofemoral pain. Current evidence supports exercise therapy as the first line of treatment for pain relief, improved function, and enhanced quality of life in individuals with patellofemoral pain. However, the most recent consensus on patellofemoral pain highlighted a gap in the ideal dosage, volume, and weekly exercise frequency for treating these individuals.
To address this gap, this study will compare two groups of individuals with patellofemoral pain who will undergo the same exercise program targeting the muscles of the hip and knee joints but with different frequencies. One group will perform the exercises twice weekly, while the other will do so thrice.
This randomized, controlled, double-blind clinical trial will recruit 84 physically active participants of both sexes, aged 18 to 40 years, who experience patellofemoral pain. Participants will be randomly and secretly allocated to one of two groups. Group A will perform the exercise protocol three times per week, and Group B will perform the same protocol twice weekly.
The intervention will last for six consecutive weeks. Participants will be evaluated at multiple time points: before the intervention, after the 4th and 6th week of intervention, and at 6 months and 1 year post-intervention. The evaluations will include pain intensity as a primary outcome, anterior knee pain during daily activities, kinesiophobia, pain-related self-efficacy, chronic pain-related self-efficacy, catastrophizing, muscle strength and 3d movement analysis as a secondary analysis.
The data analysis will follow the intention-to-treat principle, meaning all participants will be included in the analysis regardless of whether they completed the treatment as planned. Normality tests will be conducted to verify data distribution, and appropriate statistical tests will be used to compare differences within and between the two groups, considering time and group factors. A 5% level of significance will be adopted for statistical comparisons.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Strengthening 2 times per week | Experimental | Other: Strengthening 2 times per weekThis group will consist of participants with patellofemoral pain and will receive treatment twice a week. |
| Strengthening 3 times per week | Other | Other: Strengthening 3 times per weekThis group will consist of participants with patellofemoral pain and will receive treatment twice a week. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
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 |
|---|---|---|
| Strengthening 2 times per weekThis group will consist of participants with patellofemoral pain and will receive treatment twice a week. | Other | Strengthening 2 times per week |
| Strengthening 3 times per weekThis group will consist of participants with patellofemoral pain and will receive treatment thrice a week. | Other | Strengthening 3 times per week |
Primary outcome
Pain intensity
Time frame: Evaluations will occur at five time frames: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Visual Analog Pain Scale: This scale aims to quantify the intensity of pain experienced by the patient. The scale consists of 11 points, with a score classification from 0 to 10. A score of 0 represents "no pain at all", and 10 means "the worst pain possible". Patients will be asked to rate their anterior knee pain intensity levels based on the past fifteen days. The minimum clinically important difference for improvement will be a decrease of 1 point on the scale.
8 secondary outcomes
Anterior Knee Pain Scale
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Tampa Scale for Kinesiophobia
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Pain Self-Efficacy Questionnaire
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Chronic Pain Self-Efficacy Scale
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Pain Catastrophizing Scale
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Global Perceived Effect Scale
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.
Maximum isometric muscle strength
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment.
Three-dimensional movement analysis
Time frame: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment
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 5 Feb 2025.
- Individual participant dataSharing planned: No
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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.
PAULO RG LUCARELI, PhD study chair
Nove de Julho University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Strengthening 2 times per week and Strengthening 3 times per week in people with Anterior Knee Pain, run by University of Nove de Julho at 1 site in Brazil.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
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: enrolling by invitation, as of the sponsor's last update on 5 Feb 2025. 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 Brazil. 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?
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?
Pain intensity (time frame: Evaluations will occur at five time frames: 24 hours before the first treatment session, after the 4th and 6th weeks of treatment, and 6 months and 1 year after the last session.). 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 5 Feb 2025; AzTrials last refreshed its copy on 8 Nov 2026.