Quadriceps Strengthening at Different Angles in Patellofemoral Pain
NCT Number: NCT06502795
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Patellofemoral Pain Syndrome
Interventions: OTHER: Protected Range Quadriceps Strengthening group|OTHER: Patient-Guided Range Quadriceps Strengthening group
Sponsor: Universidade Federal do Ceara
Sex: ALL
Age: ADULT
Enrollment: 110
Study Design: Allocation: RANDOMIZED|Intervention Model: PARALLEL|Masking: DOUBLE (PARTICIPANT, INVESTIGATOR)|Primary Purpose: TREATMENT
Start Date: 2024-09-26
Completion Date: 2026-06

Summary:
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.

Primary Outcome Measures: 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., 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., Kinesiophobia assessed by the Tampa Scale of Kinesiophobia after six-week intervention.
Secondary Outcome Measures: 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., 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., 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., 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., 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., 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., 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., Quadriceps strength measured by the isokinetic dynamometer after six-week intervention.