Clinical Subgroups in Patellofemoral Pain Syndrome

Study Overview
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Brief Summary
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Patellofemoral pain syndrome (PFPS) is a multifactorial pathology characterized by diffuse retropatellar and peripatellar pain in the knee joint, exacerbated by overloading activities on the patellofemoral joint. However, this disease showed high degree of patients not responsive to therapeutic strategies. This condition occurred because several factors is related to disease such as: (1) proximal factors (involving trunk and hip), (2) local factors (surrounding and or within the patellofemoral joint) and (3) distal factors (involving ankle and foot). Thus, the identification of clinical subgroups based in anatomic changes (proximal, local and distal factors) is a recent strategy that could help in the therapeutic strategies focused on the etiology of the disease, improve responsiveness to treatment, clinical and functional benefits.

Official Title
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Clinical Subgroups Identification in Patellofemoral Pain Syndrome Patients

Conditions
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Patellofemoral Pain Syndrome

Intervention / Treatment
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* Diagnostic Test: Neuromuscular evaluation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Peripatellar or retropatellar pain in at least two of the following situations: squatting, running, kneeling, jumping, climbing or descending stairs and sitting for a prolonged period of time for at least three months. Exclusion Criteria: Engaged in systematic exercise with focus on lower limb in the last six months and Had an injury to the hip and ankle joint in the last 12 months.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patellofemoral pain syndrome with changes in proximal factors<br> | Diagnostic Test: Neuromuscular evaluation<br>* (1) Muscle trunk endurance test; (2) Hip isometric strength (abductor, lateral rotation, extension); (3) Knee extensor isometric strength; (4) unilateral squat; (5) navicular drop test; (6) muscle architecture at rest of gluteus medius, gluteus maximus,vastus lateralis, vastus medialis and rectus femoris; (7) muscle activation during unilateral squat (gluteus and quadriceps muscles); (8) pennation angle of obliques vastus medialis; (9) medial patellofemoral ligament length; (10) knee pain.<br>|
| Patellofemoral pain syndrome with changes in local factors<br> | Diagnostic Test: Neuromuscular evaluation<br>* (1) Muscle trunk endurance test; (2) Hip isometric strength (abductor, lateral rotation, extension); (3) Knee extensor isometric strength; (4) unilateral squat; (5) navicular drop test; (6) muscle architecture at rest of gluteus medius, gluteus maximus,vastus lateralis, vastus medialis and rectus femoris; (7) muscle activation during unilateral squat (gluteus and quadriceps muscles); (8) pennation angle of obliques vastus medialis; (9) medial patellofemoral ligament length; (10) knee pain.<br>|
| Patellofemoral pain syndrome with changes in distal factors<br> | Diagnostic Test: Neuromuscular evaluation<br>* (1) Muscle trunk endurance test; (2) Hip isometric strength (abductor, lateral rotation, extension); (3) Knee extensor isometric strength; (4) unilateral squat; (5) navicular drop test; (6) muscle architecture at rest of gluteus medius, gluteus maximus,vastus lateralis, vastus medialis and rectus femoris; (7) muscle activation during unilateral squat (gluteus and quadriceps muscles); (8) pennation angle of obliques vastus medialis; (9) medial patellofemoral ligament length; (10) knee pain.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscular strength tests of hip and knee muscles. | Isometric torque of knee extensor muscles, hip abductor, extension and medial rotation muscles through hand-held dynamometer tests will be performed to create clinical subgroups after cluster analysis for a focused intervention in the second step. | 1 day | 
| Muscle thickness measures | Muscle thickness (in millimeters) of vastus lateralis, vastus medialis and rectus femoris muscle. Muscle thickness of gluteus medius, maximus and peroneus muscle through ultrasound equipment. Tests Test will be performed to create clinical subgroups after cluster analysis for a focused intervention in the second step. | 1 day | 
| Muscle activation of knee, hip and foot muscles | Muscle activation measures of quadriceps, gluteus maximus, gluteus medius and peroneus muscles during unilateral squat through surface electromyography. Tests will be performed to create clinical subgroups after cluster analysis for a focused intervention in the second step. | 1 day | 
| Kinematics during unilateral squat | Pelvis, hip, knee and ankle angular displacement during unilateral squat through kinematics analysis. Tests will be performed to create clinical subgroups after cluster analysis for a focused intervention in the second step. | 1 day | 
| Fascicle length measures | Fascicle length (in milimeters) of vastus lateralis, vastus medialis and rectus femoris muscle through ultrasound equipment. Tests Test will be performed to create clinical subgroups after cluster analysis for a focused intervention in the second step. | 1 day | 
| Pennation angle measures | Pennation angle (in °) of vastus lateralis, vastus medialis and rectus femoris muscle through ultrasound equipment. Tests Test will be performed to create clinical subgroups after cluster analysis for a focused intervention in the second step. | 1 day |