The present study is the first one to compare the effectiveness of adding (FNG) versus (LPM ) to conventional exercise therapy in pain, knee functional abilities, hip extension ROM and femoral nerve electrophysiological studies among those with PFPS.

This study will be conducted at the outpatient clinic of faculty of Physical Therapy, Cairo University Sixty patients with unilateral PFPS referred from an orthopaedic surgeon for selection criteria, will be included in the study. Measurement procedures, treatment procedures, and the study's goal will be explained to each patient before participation in the study. After being informed about the study aim, they will be asked to sign an informed consent for their approval to participate

The study patients will be randomly assigned into three groups

• Group A: control group will receive conventional hip-knee focused exercises only.
• Group B: study group will receive FNG in addition to the same conventional hip-knee focused exercises.
• Group C: study group will receive LPM in addition to the same hip-knee focused exercises All patients will receive 2 sessions/week for 6 weeks (12 sessions). They will be instructed to do the conventional hip-knee exercises at least two times per day. Each session will last for 20-30 minutes.

Patients diagnosed with unilateral PFPS will be screened based on the following inclusion and exclusion criteria A sample size of 60 participants will be appropriate. The computations will done using G* Power version 3.1.9.2 (Franz Faul, Uni Kiel, Germany) Randomization and blinding will be accomplished through using selected types such as A 1:1:1 allocation ratio will be employed for randomization using the website http://www.randomization.com. Blinding will be done on the patients, assessor, and statistician. All patients will be blinded to the task assigned to their group by ensuring they will be unaware of the exercises that the other group will complete. To maintain blinding, the intervention sessions will be administered to each member of the treatment group separately. Before the trial began, an impartial research assistant who will not participating in the study and he will keep the allocation sequence a secret. It will be kept hidden in opaque, sealed envelopes that will not be opened until baseline data will be collected

Outcome Measures:

1. Knee Pain
2. Knee function
3. Electro-physiological studies including (sensory nerve conduction velocity and distal latency).
4. Sagittal plane hip extension range of motion as a reference for femoral nerve mechanosensitivity changes - The outcomes will be measured at baseline (pre-test) and after 12sessions (after 6 weeks) (post-test) Then patients will receive 4 types of assessments step's including pain assessment using NRS then knee function assessment using arabic version of AKPS then hip extension ROM assessment using digital goniometer after that the electrophysiological studies including femoral nerve will be conducted using the computerized electromyography device for measuring selective parameters such nerve conduction velocity and its amplitude along with onset and peak latency.

Then Intervention will be completed as follow : All patients will receive two treatment session per week for six weeks (6 sessions), supervised by primary investigator. Separate sessions will be given to each treatment group's members. Each session lasted for 15-30 minutes. The three groups will receive hip-knee focused exercises approved by the clinical practice guidelines linked to the international classification of functioning, disability, and health from the Academy of Orthopedic Physical Therapy of the American Physical Therapy Association which consisted of hamstring/calf and ilio-tibial band stretching and hip/knee strengthening exercises. group B will receive FNG addition to hip-knee focused exercises. group C will receive LPM in addition to hip-knee focused exercise. The session of the control group will start with stretching exercises followed by strengthening exercises. On the other hand, the study group session will start with stretching exercises followed by femoral nerve glide and/or LPM then strengthening ex.

The study has a 3 null hypothesis

1. There will be no statistically significant effects of adding FNG to conventional exercises in patients with PFPS on:

   A) Knee pain. B) Functional abilities. C) Hip extension ROM. D) Electrophysiological study (NCV and distal latency).

2. There will be no statistically significant effects of adding LPM to conventional exercises in patients with PFPS on:

   A) Knee pain. B) Functional abilities. C) Hip extension ROM. D) Electrophysiological study (NCV and distal latency).

3. There will be no statistically significant difference between adding FNG versus LPM to conventional exercises in patients with PFPS on:

A) Knee pain. B) Functional abilities.C) Hip extension ROM. D) Electrophysiological study (NCV and distal latency).

Inclusion Criteria:

• Age of the subjects is between 18-35 years.
• BMI will be from 18.5 to ≤ 29.5 Kg/m2
• Anterior or retro patellar knee pain either on the dominant or non- dominant leg for at least 6 weeks duration .
• Worst pain level in the previous month of up to 3cm on a 10cm numerical rating scale (NRS)
• Per or retropatellar pain during at least 2 of the following activities: squatting, prolonged sitting, kneeling, running, jumping and climbing stairs
• Showing 2 or more positive signs on the following clinical tests: Clarke's sign, Waldron test, active patellar grind test, patellar compression test, and palpation of the medial/lateral articular border of the patella .
• Patients had positive femoral slump test with limited active lumber ROM.

Exclusion Criteria:

• History of previous knee surgery and any knee pathology (meniscus tear, patellar tendinopathy, ligament sprain and osteoarthritis) .
• Any systemic diseases and/or connective tissue disorders .
• Bursitis and ligament tears .
• Lower back dysfunction such as disc lesion, sciatica or spondylolisthesis.
• participants that had undergone physiotherapy during the preceding 3 month.
• Pregnant women.
• Osteoporosis or recent fracture of the hip or spinal joints.• . Radiographic evidence or medical diagnosis of spinal instability (Grade II spondylolithesis or greater), spondyloarthritides, or severe spinal misalignment
• Nervous system disease or disorder
• .Lumbosacral nerve root compression (any of the following signs present) a. Positive straight leg raise (SLR) test less than 45°, marked paresis (<3/5 on manual muscle testing) involving a major muscle group of the lower extremity, diminished, and asymmetric (lower than uninvolved side), lower extremity muscle stretch reflex and diminished or absent sensation to pinprick in any lower extremity dermatome (D'Agati M 2022).