Comparison of the Effects of Isometric, Isotonic, and Eccentric Vastus Medialis Oblique Strengthening Exercises Applied in Terminal Knee Extension Range on Pain, Function, and Muscle Architecture in Individuals With Patellofemoral Pain Syndrome: A Randomized Controlled Trial
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 90
- 试验地点
- 1
- 主要终点
- VMO Muscle Architecture (Ultrasound)
研究概览
简要总结
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.
详细描述
Patellofemoral pain syndrome (PFPS) is a prevalent condition affecting physically active individuals and is associated with anterior knee pain during functional activities. Alterations in patellofemoral joint biomechanics, particularly related to quadriceps muscle imbalance and insufficient activation of the vastus medialis oblique (VMO), are considered key contributing factors.
Although VMO strengthening is widely used in clinical practice, there is limited evidence comparing the effects of different contraction types-specifically isometric, isotonic, and eccentric exercises-applied within the terminal knee extension range (0-30°), where patellofemoral joint stress and stabilization demands are highest.
This study is designed as a three-arm, parallel-group, randomized controlled trial to investigate the comparative effects of these exercise modalities on pain, functional outcomes, and muscle architecture. The intervention period will last 8 weeks, with sessions conducted three times per week.
A total of 90 participants aged 18-40 years with clinically diagnosed PFPS will be recruited and randomly allocated into three groups: isometric, isotonic, and eccentric exercise groups. All participants will receive a standardized physiotherapy protocol including superficial heat application, transcutaneous electrical nerve stimulation (TENS), and therapeutic ultrasound prior to exercise.
Primary outcomes will include pain intensity assessed by the Visual Analog Scale (VAS) and functional status evaluated using the WOMAC index, 30-second sit-to-stand test, and stair ascent/descent test. Secondary outcomes will include ultrasonographic assessment of muscle architecture, including muscle thickness, fascicle length, pennation angle, and physiological cross-sectional area of the VMO muscle. Additionally, selected hip muscles (adductor group and tensor fascia lata) will be evaluated.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
盲法说明
Outcome assessments will be performed by a physiotherapist who is blinded to group allocation.
入排标准
- 年龄范围
- 18 Years 至 50 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •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
- •Pain intensity of at least 3/10 on the Visual Analog Scale (VAS)
- •Willingness to participate and provide written informed consent
排除标准
- •History of knee trauma or surgery
- •Meniscal injury, ligament injury, or knee instability
- •Advanced osteoarthritis
- •Neurological disorders
- •Rheumatologic diseases
- •Participation in a structured knee rehabilitation program within the last 6 months
- •Pregnancy
研究组 & 干预措施
Eccentric Exercise Group
Participants will receive the same standardized physiotherapy program followed by eccentric VMO strengthening exercises performed within the 0-30° knee extension range. Exercises will be performed 3 sets of 10-15 repetitions, three times per week for 8 weeks.
干预措施: Eccentric VMO Exercise (Other)
Isotonic Exercise Group
Participants will receive the same standardized physiotherapy program followed by isotonic (concentric and eccentric) VMO strengthening exercises performed within the 0-30° knee extension range using external resistance. Exercises will be performed 3 sets of 10-15 repetitions, three times per week for 8 weeks.
干预措施: Isotonic VMO Exercise (Other)
Isometric Exercise Group
Participants in this group will receive a standardized physiotherapy program (hot pack, TENS, and therapeutic ultrasound) followed by isometric VMO strengthening exercises performed in the terminal knee extension range (0-30°). Exercises will be performed 3 sets of 10 repetitions, with 10-second contractions, three times per week for 8 weeks.
干预措施: Isometric VMO Exercise (Other)
结局指标
主要结局
VMO Muscle Architecture (Ultrasound)
时间窗: Baseline and Week 8
Muscle thickness, fascicle length, pennation angle, and physiological cross-sectional area of the vastus medialis oblique muscle will be assessed using ultrasound imaging.
次要结局
- Pain Intensity (Visual Analog Scale, VAS)(Baseline and Week 8)
- Functional Status (WOMAC Index)(Baseline and Week 8)
- 30-Second Sit-to-Stand Test(Baseline and Week 8)
- Stair Ascent and Descent Test(Baseline and Week 8)
- Hip Muscle Architecture (Ultrasound)(Baseline and Week 8)
研究者
Muharrem Gökhan Beydağı
Assistant Professor and Principal Investigator
Firat University