This is a research study to compare two different exercises for people who have patellofemoral pain syndrome. Patellofemoral pain syndrome means pain around or behind the kneecap, which is also called "runner's knee".

People in this study will be divided into two groups by chance. One group will do clamshell exercises. This exercise strengthens hip muscles. The other group will do short arc quadriceps exercises. This exercise strengthens thigh muscles near the knee. Both groups will do their exercises for the same number of weeks.

The main goal of this study is to see which exercise reduces knee pain better and helps patients do daily activities more easily. We will also check if quality of life improves after doing these exercises.

Pain level, knee function, and quality of life will be checked before starting exercises and again after finishing the exercise program.

The results may help doctors and physical therapists choose the best exercise for patients with kneecap pain.

This randomized parallel-group clinical trial will compare the effectiveness of clamshell exercises versus short arc quadriceps strengthening exercises in patients diagnosed with patellofemoral pain syndrome.

Study Design: Participants meeting inclusion criteria for patellofemoral pain syndrome will be randomly allocated into two intervention groups.

Group 1 - Clamshell Exercise Group: Participants will perform clamshell exercises targeting hip abductors and external rotators, specifically gluteus medius and gluteus maximus muscles.

Group 2 - Short Arc Quadriceps Group: Participants will perform short arc quadriceps strengthening exercises focusing on quadriceps femoris muscle, with emphasis on vastus medialis obliquus activation.

Intervention Duration: Both groups will follow supervised exercise protocols for [X weeks]. Frequency and repetitions will be as per standard protocol.

Outcome Measures:

Primary: Pain intensity using Visual Analog Scale, Functional disability using Kujala Anterior Knee Pain Scale, Quality of Life using SF-36 questionnaire.

Assessments will be conducted at baseline, mid-intervention, and post-intervention to compare changes between the two exercise groups.

Hypothesis: Clamshell exercises targeting hip muscles may show superior effects on pain and function compared to short arc quadriceps exercises in PFPS patients.

Inclusion Criteria:

Patients diagnosed with Patellofemoral Pain Syndrome Age between 18-40 years. Male and female participants Presence of anterior knee pain for at least 4 weeks Pain aggravated by activities such as stair climbing, squatting, running, or prolonged sitting Willingness to participate and provide informed consent

Exclusion Criteria:

History of knee surgery or fracture around the knee joint Ligament injuries (e.g., ACL, PCL tears) or meniscal injuries Presence of other knee conditions (e.g., osteoarthritis, patellar dislocation). Neurological disorders affecting lower limb sensations and gait Current participation in any other physiotherapy or rehabilitation program Systemic inflammatory conditions (e.g., rheumatoid arthritis). Cognitive impairment or inability to follow instructions/attend sessions. Use of long-term steroids, strong analgesics, or anti-inflammatory medications.

Only IPD used in the results publication willbe shared.

It will be available after the completion of the study.

Data requests should be sent to the corresponding author. Access will be granted to qualified researchers for approved research proposals. Data will be de-identified before sharing.