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NCT Number: NCT06502795

Quadriceps Strengthening At Different Angles in Patellofemoral Pain

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.

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Key information

Conditions

Patellofemoral Pain Syndrome Cartilage Diseases Chondromalacia Patellae Connective Tissue Diseases Joint Diseases Musculoskeletal Diseases Skin and Connective Tissue Diseases

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Physiotherapy Department, Federal University of Ceará

Fortaleza, Ceará, 60430-450, Brazil

Location status: Recruiting

Location contact

Gabriel PL Almeida, PhD

CONTACT

[email protected]

+55 (85) 3366 8091

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Individuals aged between 18 and 35 years.
  • Diagnosis of patellofemoral pain characterized by peri- or retropatellar pain.
  • Pain reproduced in at least two of the following activities: ascending or descending stairs, squatting, kneeling, prolonged sitting, jumping, running, or palpation of the medial and/or lateral facets of the patella.
  • Insidious onset of symptoms.
  • Symptoms duration of at least three months.
  • Minimum score of three on the numerical pain rating scale (NPRS) in the past week.
  • Maximum score of 86 points on the Anterior Knee Pain Scale (AKPS)
  • In cases of bilateral pain, the more symptomatic knee will be included.

Exclusion criteria

  • History of surgery and/or fractures in the lower limb joints.
  • Other knee joint-related injuries such as meniscal tears, ligament injuries.
  • History of patellar subluxation or dislocation.
  • Signs of osteoarthritis.
  • Patellar and quadriceps tendinopathy.
  • Osgood-Schlatter syndrome.
  • Presence of knee joint edema.
  • Contraindications to resistance exercises informed by a physician.
  • Corticosteroid injection within the last 6 months.

Treatment and study plan

Protected Range Quadriceps Strengthening group

Other

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.

Patient-Guided Range Quadriceps Strengthening group

Other

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.

Primary outcomes

  1. Knee pain intensity

    Time frame: Knee pain intensity measured by the NPRS after six-week intervention.

    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.

  2. Kinesiophobia

    Time frame: Kinesiophobia assessed by the Tampa Scale of Kinesiophobia after six-week intervention.

    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.

Secondary outcomes

  1. Perception of effect

    Time frame: Global Rating of Change Scale after six-week intervention and six-month follow-up.

    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.

  2. Knee crepitus

    Time frame: Crepitus during knee extension after six-week intervention.

    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.

  3. Weekly analgesic consumption

    Time frame: Weekly, throughout the six-week intervention period.

    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.

  4. Knee pain intensity

    Time frame: Knee pain intensity measured by the NPRS at six-month follow-up.

    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.

  5. Knee function

    Time frame: Self-reported function measured by the AKPS at six-week and six-month follow-up.

    Anterior Knee Pain Scale - AKPS: Specific questionnaire for anterior knee pain comprising 13 items with separate categories related to different levels of knee function.

  6. Kinesiophobia

    Time frame: Kinesiophobia assessed by the Tampa Scale of Kinesiophobia six-month follow-up.

    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.

  7. Quadriceps peak torque

    Time frame: Quadriceps strength measured by the isokinetic dynamometer after six-week intervention.

    Peak torque (Nm) and limb symmetry index on the isokinetic dynamometer, angular velocity of 60 degrees per second, and CON/CON mode.

Study contacts

Contact information is provided by the study sponsor or research team.

Ana Karine S Nunes, PT

CONTACT

[email protected]

+55(85)988302157

Gabriel Almeida, DSc

CONTACT

[email protected]

+55(85)999590400

Sponsors and collaborators

Lead sponsor

Universidade Federal do Ceara

Other

Registry information

Official study title

Quadriceps Strengthening Under Limited Range of Motion Compared to Patient-guided Range of Motion on Pain, Kinesiophobia and Function in Individuals with Patellofemoral Pain: a Randomized Clinical Trial

Important dates

Study start
2024
Primary completion
2024
Study completion
2026
First posted
Jul 16, 2024
Registry last updated
Oct 30, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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