The Effect of Blood Flow Restriction Method in Patellar Instability

Study Overview
=================
Brief Summary
-----------------
The blood flow restriction method, the effects of which have been frequently investigated in the literature in recent years, can produce muscle hypertrophy with low-intensity load and can be easily tolerated through to low mechanical stress, seems to be an exercise approach that can be used in the recovery of strength in cases with minor patellar instability and can contribute to the recovery of functional capacity without delay.

Detailed Description
-----------------
Patellar instability is defined as disruption of normal movement of the patella in the trochlear groove, symptomatic, medial-lateral displacement. Patients with patellar instability may not be able to tolerate high-intensity quadriceps exercises in the early period of strengthening programs due to pain symptoms, and therefore strength recovery may be delayed. However, it is important to restore muscle strength, especially vastus medialis obliquus strength, as early as possible in patellar instability. The blood flow restriction method, the effects of which have been frequently investigated in the literature in recent years, can produce muscle hypertrophy with low-intensity load and can be easily tolerated through to low mechanical stress, seems to be an exercise approach that can be used in the recovery of strength in cases with minor patellar instability and can contribute to the recovery of functional capacity without delay.

Official Title
-----------------
The Effect of Blood Flow Restriction Applied to the Extensor Muscles on Muscle Architecture and Strength, Knee Pain, and Functions in Minor Patellar Instability

Conditions
-----------------
Patellar Abnormality

Intervention / Treatment
-----------------
* Other: Rehabilitation with blood blow restriction
* Other: Rehabilitation without blood flow restriction


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Being between the ages of 18-40 years, Volunteering to participate in the study, Having a complaint of anterior knee pain for at least 3 months, Having been diagnosed with unilateral minor patellar instability, Absence of any other ongoing clinical problems that interfere with exercise (will be questioned by the Physical Activity Readiness Questionnaire for All). Exclusion Criteria: History of one or more traumatic-atraumatic patella dislocations, Evidence of osteoarthritis on radiological imaging (≥ Kellgren-Lawrence Stage 2) Having at least one of the contraindications preventing the application of blood flow restrictive exercises (Smoking, previous venous thromboembolism, risk of peripheral vascular disease (ankle-brachial index <0.9), coronary heart disease, hypertension, hemophilia, etc.), Previously diagnosed cardiovascular disease limiting effort capacity (Myocardial infarction, angina, exercise intolerance, etc.), Previously diagnosed neurological disorder or cognitive dysfunction (stroke, dementia, schizophrenia, etc.), Orthopedic lower extremity surgery in the last 1 year, Body mass index ≥ 30 kg/m2.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: With Blood Flow Restriction<br> | Other: Rehabilitation with blood blow restriction<br>* The rehabilitation program will be applied 2 days a week, for total of 8 weeks.<br>|
| Active Comparator: Without Blood Flow Restriction<br> | Other: Rehabilitation without blood flow restriction<br>* The rehabilitation program will be applied 2 days a week, for total of 8 weeks.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of Muscle Architecture and Hypertrophy | A portable, diagnostic B-mode ultrasound device with a linear probe will be used to evaluate the quadriceps muscle architecture. Cross-sectional areas, muscle thicknesses, fascicle lengths, and pennation angles, the architectural parameters of both thigh muscles, will be assessed by ultrasound. All assessments will be calculated as millimeters. | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of Muscle Strength | The concentric and eccentric strength of the knee extensor muscle (quadriceps) and its antagonist (hamstring), will be measured using the isokinetic dynamometer. | 8 weeks | 
| Assessment of Pain | Visual Analogue Scale (VAS) will be used to evaluate the severity of pain in the knee of patients during activity, at rest, and at night. In the evaluation of pain intensity with VAS, the patient is asked to mark his pain above the 10-centimeter line defined as 0-no pain and 10 unbearable pain at both ends. | 8 weeks | 
| Evaluation of Functions | The Tampa Kinesiophobia Scale (TKS) will be used to evaluate kinesiophobia. The lower extremity functional capacity of the subjects will be evaluated with the 1-minute sit-to-stand test, and the knee functions will be evaluated with the Lysholm Knee Scoring Scale and the Kujala Patellofemoral Joint Evaluation Scale, which are patient-answered scales that are recommended to be used in cases with patellar instability. In addition, fatigue determination after each application will be made with the Borg CR-10 Perceived Fatigue Scale. Scales will be filled by the face-to-face evaluation method. | 8 weeks | 
| Evaluation of Satisfaction and Change | General satisfaction and the change in clinical status perceived by the participants will be evaluated with the 7 points Global Rating of Change Scale after the rehabilitation program. According to the scale, it is expressed as -3: I am much worse, -2: I am worse, -1: I am a little worse, 0: No change, 1: I am a little better, 2: I am better, 3: I am much better. | 8th week |