An interventional study of Protected Range Quadriceps Strengthening group and Patient-Guided Range Quadriceps Strengthening group in Patellofemoral Pain Syndrome, sponsored by Universidade Federal do Ceara. Recruiting at 1 site in Brazil. Open to participants aged 18 Years to 35 Years. Per ClinicalTrials.gov, last updated 2024-10-30.
Sponsored by Universidade Federal do Ceara · Not applicable, Interventional, and Treatment
Among 21 studies in Patellofemoral Pain Syndrome with a site in Brazil — 3 open to participants now, 3 under way, none of them phase 3. Patellofemoral Pain Syndrome · Brazil.
Among the 21 studies in Patellofemoral Pain Syndrome with a site in Brazil, this one is the 2nd largest by planned enrollment of the 19 interventional ones, is one of 2 that started in 2024, is one of 18 with no phase, and was the 20th registered.
297 studies on the registry are indexed under Patellofemoral Pain Syndrome; 74 are open to participants now.
This study's planned enrollment of 110 is above the median of 45 across 244 interventional studies indexed under Patellofemoral Pain Syndrome.
Browse Patellofemoral Pain Syndrome studies →3 of the 21 studies in Patellofemoral Pain Syndrome with a site in Brazil are open now, in 1 country. Each count lists the studies.
Of the 45 Patellofemoral Pain Syndrome studies recruiting now, 3 (7%) set no upper age limit and 41 (91%) stop at 75 or younger; 7 take children under 18; 13 take healthy volunteers.
This study: 18 Years to 35 Years · all sexes · no healthy volunteers.
The full table on the hub →21 studies; the count open now beside each. This study's row is marked.
First in 2008; this study’s year is marked. 2 started in 2024.
Median enrollment 40 across the 19 interventional studies, 39 across the 2 observational. Of the 12 that completed or were terminated, 0 (0%) have results posted.
None of the 21 has an industry lead sponsor. The 9 most frequent:
Universidade Federal do Ceara is the lead sponsor of 22 studies on the registry; 3 are open to participants now.
Universidade Federal do Ceara has 4 studies filed under Patellofemoral Pain Syndrome — fewer than ten, so there is no comparison to draw.
1 of the studies in Patellofemoral Pain Syndrome with a site in Brazil that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06808386University of Nove de JulhoEffects of Training Frequency on Patellofemoral Pain Rehabilitation. | 2026-11-30 |
Among the 21 studies in Patellofemoral Pain Syndrome with a site in Brazil, from their registry updates:
Nothing recorded among them since 2026-09-25.
Introduction: Patellofemoral pain (PFP) is characterized by anterior, retropatellar and/or peripatellar pain during activities such as running, squatting, kneeling, or prolonged sitting. This condition affects approximately 25% of the general population. Given its complex and multifactorial etiology, PFP presents a significant treatment challenge. All clinical practice guidelines recommend strengthening the quadriceps femoris muscle as a key component in the management of PFP. However, exercises aimed at strengthening the quadriceps place considerable stress on the patellofemoral joint and are often poorly tolerated by patients. Clinicians commonly employ a conservative strategy that restricts open kinetic chain knee extension exercises to a limited range of 90° to 45° of knee flexion and closed kinetic chain exercises to 0° to 45°. Yet, restricting the range of motion may result in suboptimal outcomes for patients with higher load tolerance and may foster beliefs regarding knee joint fragility.
Objective: We aim to compare the effects of quadriceps femoris strengthening within a limited range to a patient-guided range of motion on pain, function, knee confidence, and kinesiophobia in individuals with PFP.
Methods: A randomized clinical trial will be conducted with two parallel groups, using a balanced 1:1 allocation and a double-blind design. The study population will include men and women aged 18 to 35 years, diagnosed with PFP. Participants will be randomly assigned to either the limited range group or the patient-guided range of motion group. They will participate in a supervised therapeutic protocol, with sessions averaging 40 minutes, twice a week, for six consecutive weeks. The primary outcome will be pain, assessed using the numerical pain rating scale (0-10), and kinesiophobia, assessed by the Tampa Scale . Secondary outcomes will include pain, self-reported function, measured by the Anterior Knee Pain Scale (AKPS), perceived improvement by the Global Rating of Change Scale, quadriceps strength, kinesiophobia and analgesic consumption.
Participants with patellofemoral pain will be randomized into two intervention groups. All participants will start with a warm-up on a stationary bike, followed by dynamic stretching exercises targeting the quadriceps, hamstrings, calf muscles, adductors, and abductors.
Open kinetic chain exercises will be performed using a leg extension machine, while closed kinetic chain exercises will include free squats and Bulgarian squats.
The Limited-RoM Quadriceps Strengthening group will perform open-kinetic-chain quadriceps strengthening exercises within a range of 90° to 45° of knee flexion and closed-kinetic-chain within a range of 0° to 45°.
The Patient-Guided-RoM Quadriceps Strengthening group will perform quadriceps strengthening exercises in both open and closed kinetic chains to the maximum tolerated by the patient based on their symptoms. The patient-guided maximum range of motion will be adjusted based on pain intensity, comfort, and patient response, following a shared decision-making approach with a clinician. The goal will be to maintain exercises at the greatest possible range of motion.
The identification of the patient-guided angle in both open and closed kinetic chain exercises will be determined as follows: the patient will perform 10 maximum repetitions on the leg with PFP, prioritizing range of motion over load. During the execution, the range of motion and load will be guided by the numerical pain rating scale and the perceived exertion scale.
Participants will complete 12 sessions, twice a week, supervised by a physiotherapist. Assessments will be conducted at baseline, six weeks, and six months, evaluating pain, function, kinesiophobia, crepitus, perception of effect, and weekly pain-killer consumption.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The Limited-RoM Quadriceps Strengthening group will perform open-kinetic-chain quadriceps strengthening exercises within a range of 90° to 45° of knee flexion and closed-kinetic-chain within a range of 0° to 45°.
Other: Protected Range Quadriceps Strengthening group
The Patient-Guided-RoM Quadriceps Strengthening group will perform quadriceps strengthening exercises in both open and closed kinetic chains to the maximum tolerated by the patient based on their symptoms. The patient-guided maximum range of motion will be adjusted based on pain intensity, comfort, and patient response, following a shared decision-making approach with a clinician. The goal will be to maintain exercises at the greatest possible range of motion.
Other: Patient-Guided Range Quadriceps Strengthening group
Warm-up: Start with 5 minutes of stationary biking. Then, proceed with two sets of 30-second dynamic stretches targeting the quadriceps, hamstrings, calf muscles, and adductors, followed by static stretching for the abductors. Strengthening: Complete 3 sets of 8-12 repetitions for each exercise, aiming for a perceived effort level on the Borg scale between 60% and 80%. Increase the load by 2%-10% when the patient can perform 14 or more repetitions in the final set while maintaining the Borg scale between 60% and 80%. For the Leg Extension Machine, maintain a range of motion between 90 to 45 degrees. During Squats and Bulgarian Squats, aim for a range of motion between 0 to 45 degrees.
Warm-up: 5 minutes of stationary biking. Next, perform two sets of 30-second stretches for the quadriceps, hamstrings, calf muscles, adductors and abductors hip. Strengthening: Patients will complete 3 sets of 8 to 12 repetitions for each exercise, aiming for a perceived effort level of 60% to 80% on the Borg scale. Load will be increased by 2% to 10% when patients can complete 14 or more repetitions in the final set while maintaining the Borg scale between 60% and 80%. Quadriceps strengthening will be performed at the patient's maximum range guided by symptoms, with pain intensity capped at 5 points on the NPRS. The patient-guided range will be adjusted based on pain intensity, comfort, and patient response, using a shared decision-making approach. The goal is to maintain exercises at the maximum possible range of motion. For the Leg Extension Machine, Squats, and Bulgarian Squats, the range of motion will be guided by the patient's pain tolerance.
Knee pain intensity
Pain intensity will be measured using the numeric pain rating scale (NPRS), which ranges from 0 to 10 points, where 0 represents no pain and 10 represents the worst possible pain.
Time frame: Knee pain intensity measured by the NPRS after six-week intervention.
Kinesiophobia
The Tampa Scale is a 17-item questionnaire designed to quantify fear of movement and re-injury due to movement and physical activity on a scale from 17 to 68, where 68 indicates higher fear of re-injury due to movement.
Time frame: Kinesiophobia assessed by the Tampa Scale of Kinesiophobia after six-week intervention.
Perception of effect
Global Rating of Change Scale- This scale consists of 11 points ranging from minus five (extremely worse), zero (no change) to five (completely recovered). For all measures of perceived global effect, participants were asked: "Compared to the beginning of this episode, how would you describe your knee today?" Positive scores indicate better recovery, while negative scores indicate worsening of symptoms.
Time frame: Global Rating of Change Scale after six-week intervention and six-month follow-up.
Knee crepitus
The investigator places the palm of their hand over each participant's patella to detect the presence of a grinding sensation during knee extension performed on the leg extension machine. Participants will be instructed to perform two knee extensions as far as they can during the assessment. The test will be considered positive for knee crepitus when a grinding or popping sensation is detected during the range of motion. However, one or two occasional pops will not be considered crepitus. This test has been previously conducted in individuals with PFP.
Time frame: Crepitus during knee extension after six-week intervention.
Weekly analgesic consumption
The patient will be asked if they have taken pain medications in the last week. If the answer is yes, it will be identified which medications (opioids, anti-inflammatories, or analgesics) were taken and how many medications were consumed.
Time frame: Weekly, throughout the six-week intervention period.
Knee pain intensity
Pain intensity will be measured using the NPRS, which ranges from 0 to 10 points, where 0 represents no pain and 10 represents the worst possible pain.
Time frame: Knee pain intensity measured by the NPRS at six-month follow-up.
Knee function
Anterior Knee Pain Scale - AKPS: Specific questionnaire for anterior knee pain comprising 13 items with separate categories related to different levels of knee function.
Time frame: Self-reported function measured by the AKPS at six-week and six-month follow-up.
Kinesiophobia
The Tampa Scale is a 17-item questionnaire designed to quantify fear of movement and re-injury due to movement and physical activity on a scale from 17 to 68, where 68 indicates higher fear of re-injury due to movement.
Time frame: Kinesiophobia assessed by the Tampa Scale of Kinesiophobia six-month follow-up.
Quadriceps peak torque
Peak torque (Nm) and limb symmetry index on the isokinetic dynamometer, angular velocity of 60 degrees per second, and CON/CON mode.
Time frame: Quadriceps strength measured by the isokinetic dynamometer after six-week intervention.
Plan to share: Yes — Variable characterization will employ descriptive statistical tests (frequency, mean, and standard deviation). Group differences and corresponding confidence intervals will be calculated using mixed linear models incorporating an interaction term for "time versus group." These interaction terms represent group differences (intervention effect). Covariates known to influence clinical outcomes in our study, such as bilateral/unilateral pain presence, symptom duration, and sex, will be incorporated into the statistical models. Statistical analyses will be conducted using SPSS 20.0 for Windows (Statistical Package for the Social Sciences Inc., Chicago, IL, USA) with a significance level set at 5% (α \< 0.05).
Supporting information: Statistical analysis plan
Started Oct 2024 (actual). Primary completion is estimated for Dec 2024, 2 months after the start.
Of 153 non-industry interventional studies with no phase under Patellofemoral Pain Syndrome, half reached primary completion within 11 months of starting (the median), counting those still running; a quarter within 4 and three quarters within 20. This study's planned 2 months is below that.
Counting every sponsor, half of 157 studies reached it within 11 months; a quarter within 4 and three quarters within 21.
How these figures are worked out, and which studies are left out of them.
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Patellofemoral Pain Syndrome →
Universidade Federal do Ceara