Effects of Isometric, Isotonic, and Eccentric VMO Exercises in Patellofemoral Pain Syndrome
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-50
SponsorFirat University
About this trial
Patellofemoral pain syndrome (PFPS) is a common musculoskeletal condition characterized by anterior knee pain, especially during activities such as stair climbing, squatting, running, and prolonged sitting. Weakness or delayed activation of the vastus medialis oblique (VMO) muscle is considered an important contributing factor in the development of PFPS.
This study aims to compare the effects of three different types of VMO strengthening exercises (isometric, isotonic, and eccentric) applied within the terminal knee extension range (0-30°) on pain, functional performance, and muscle architecture in individuals with PFPS.
Participants will be randomly assigned to one of three exercise groups. All participants will receive a standardized physiotherapy program, including heat therapy, TENS, and therapeutic ultrasound, followed by group-specific VMO strengthening exercises. The intervention will be performed three times per week for 8 weeks.
Outcomes will be assessed before and after the intervention and will include pain intensity (Visual Analog Scale), functional performance (WOMAC, 30-second sit-to-stand test, and stair test), and muscle architecture parameters measured by ultrasound imaging.
The results of this study are expected to provide evidence for optimizing rehabilitation strategies in individuals with PFPS.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Aged between 18 and 40 years
Clinically diagnosed with patellofemoral pain syndrome
Presence of anterior knee pain for at least 3 months
Pain during activities such as stair climbing, squatting, running, or prolonged sitting
Disqualifiers
History of knee trauma or surgery
Meniscal injury, ligament injury, or knee instability
Advanced osteoarthritis
Neurological disorders
Trial design
Design model
Parallel
Treatments tested in this trial
Isometric VMO Exercise
Other interventionIsometric contractions of the vastus medialis oblique muscle will be performed with the knee supported at approximately 15° flexion, emphasizing maximal voluntary contraction without joint movement.
Isotonic VMO Exercise
Other interventionParticipants will perform controlled concentric and eccentric contractions using ankle weights through a limited range of motion (0-30° knee extension).
Eccentric VMO Exercise
Other interventionParticipants will perform eccentric contractions against resistance during knee flexion, with assisted concentric return to the starting position.
Treatment groups
90 Participants
are divided into 3 treatment groupsGroup A: Isometric Exercise GroupExperimental treatment 1 intervention
Group B: Isotonic Exercise GroupExperimental treatment 1 intervention
Group C: Eccentric Exercise GroupExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
VMO Muscle Architecture (Ultrasound)
Muscle thickness, fascicle length, pennation angle, and physiological cross-sectional area of the vastus medialis oblique muscle will be assessed using ultrasound imaging.
Time frame
Baseline and Week 8Secondary outcomes
1
Pain Intensity (Visual Analog Scale, VAS)
Pain intensity will be assessed using the Visual Analog Scale (VAS), a 10-cm scale ranging from 0 (no pain) to 10 (worst imaginable pain). Higher scores indicate greater pain intensity.
Time frame
Baseline and Week 82
Functional Status (WOMAC Index)
Functional status will be evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), including pain, stiffness, and physical function subscales. Higher scores indicate worse functional status.
Time frame
Baseline and Week 83
30-Second Sit-to-Stand Test
The number of repetitions completed in 30 seconds will be recorded to assess lower extremity functional strength.
Time frame
Baseline and Week 84
Stair Ascent and Descent Test
Time required to ascend and descend a standardized 9-step staircase will be recorded in seconds.
Time frame
Baseline and Week 8Sponsors and contacts
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Source ClinicalTrials.gov