The Comparison of Hip and Knee Focused Exercises Versus Hip and Knee Focused Exercises With the Use of Blood Flow Restriction Training in Adults With Patellofemoral Pain
Condition: Patellofemoral Pain Syndrome
MeSH terms: Patellofemoral Pain Syndrome
Study type: Interventional

Summary: 
      Hip and Knee strengthening exercises are implemented in Patellofemoral Pain (PFP)
      rehabilitation but exercising in high loads to achieve muscle changes in strength may lead to
      increased patellofemoral joint stress. Low load training with Blood Flow Restriction (BFR)
      may allow for exercise strength benefits to proximal and distal muscles with reduced joint
      stress and by promoting hypoalgesia.

      The purpose of this study is to compare hip and knee focused exercises with and without BFR
      training in adults with PFP. The main outcome of this study is function ability which will be
      measured with the Kujala Anterior Knee pain Scale translated in the Greek language at four
      weeks post intervention and at two months follow up. Our null hypothesis is that there will
      be no difference between groups for primary and secondary outcomes measured at four weeks and
      two months post intervention.
    

Detailed description: 
      This a randomized controlled clinical trial with first primary end point at four weeks and
      second primary end point at two months.

      Sample size was determined through power analysis. The Minimal Clinically Significant
      Difference (MCID) of our main outcome measure, Kujala Anterior Knee Pain Scale, was used for
      the estimation. The MCID of the Kujala scale has been reported to be 10 points with an
      estimated standard deviation of 13,5 points. For a power of 0.80 and a level of significance
      a=0.05 and considering a two tailed t-test the sample size was calculated to be 60
      participants total (30 in each group). The GPower 3.0.10 software was used to calculate the
      sample size. By estimating a possible 20% drop out we concluded to a sample size of 75.

      The participants of this study will be volunteers and considered a sample of convenience
      since no official records or data base exists in Cyprus with all PFP patients. Participant
      recruitment will begin in November 2019. Potential participants will be informed for the
      study through printed posters around the European University Cyprus (EUC) campus, local
      social media online posters and will volunteer for inclusion. Screening will be carried out
      by an orthopedic surgeon, at the musculoskeletal laboratory of the EUC to determine their
      eligibility based on specific inclusion and exclusion criteria.

      Volunteers who meet inclusion criteria will receive oral and written information and give
      informed consent to participate in the study by signing a consent form. They will be
      randomized into one of two treatment groups. Group 1 will be the Hip and Knee Exercise group
      and Group 2 the BFR training Hip and Κnee exercise group. Randomization will be carried out
      using a block sequence of 4 by an external statistician to maintain a balance in sample size
      across groups over time and to ensure the assessor was blind to the participants allocation.

      All interventions will take place in the musculoskeletal laboratory and the training center
      lab of the EUC. Time consistency in treatments will be a goal, in order to train participants
      at similar circadian rhythm. Room temperature for both labs will be set at 25 °C. Two
      experienced physiotherapists will each be randomly assigned to supervise one of the two
      intervention groups and provide the treatment. The therapists role is to supervise treatments
      and their progression, keep track of compliance with the study design, adverse effects and
      drop outs. If patients do not comply with the study (seek other treatment for PFP, exercise
      during the study, inability to attend treatments) design they will be excluded. The two
      therapist will be blinded as to the other groups treatment protocol and the studies outcomes.
      They will be given written information for all procedures of their intervention group in
      order to ensure consistency throughout the study. Data collected by the therapists will be
      stored at the E.U.C laboratories and will only be available to them. Additionally, the
      therapists will be assisted by fourth year physiotherapy undergraduate students in
      supervising participants during treatments. Participants who fail to complete at least 10/12
      therapy sessions will be excluded and their data will not be analyzed. All therapy sessions
      will be supervise by a physician who will be in charge of participants safety. Any adverse
      events will be reported with publication of final results. Participants are free to withdraw
      from the study at any given moment. In case of any complaints, participants have the right to
      file official complaints to the university bioethics committee.

      Planed statistical analysis: Statistical analysis will be performed by the studies assessor
      who is blinded to the participants treatment group using the IBM SPSS "Statistical Package
      for the Social Sciences" (SPSS, Version 20.0). Descriptive statistics will be analyzed with
      the calculation of means, standard deviations, minimum and max values for each variable. A
      normality check will follow using the One Sample Kolmogorov-Smirnov test (p<0.05). The
      chi-squared test will be used to test for difference between the two groups with respect to
      the categorical variable gender. To check for differences within groups (baseline-4weeks,
      baseline-2months follow up and 4weeks-2months follow up) we will use the paired t-test for
      each comparison. In case of nonparametric data, the Wilcoxon signed rank test will be used.
      In order to estimate differences between the two groups (baseline-4weeks, baseline-2months
      follow up and 4weeks-2months follow up) we will use the mixed two way ANOVA with time as a
      within-subjects factor and treatment as the between subjects factor. Homogeneity of variance
      will be checked with the Levene test <0.05. In the case of not normally distributed data we
      will use the generalized mixed effect model with treatment as a fixed factor, time as a
      random factor, and inverse as the link function. Possible correlations will also be checked
      for our outcome measures using the Pearson correlation coefficient. In case of not normally
      distributed data the Spearman correlation coefficient will be used if there seems to be a
      linear correlation from a scatter plot. Missing values in the Patient Reported Outcome
      Measures will be imputed using Multiple Imputation (MI). Only upon agreement by the authors
      that there will be no further changes and/or analysis, results of the study will be
      published.
    

Intervention name(s): Exercise with Blood Flow restriction training; Hip and Knee Exercise Program; stretching
Intervention type(s): Other; Other; Other
Intervention description(s): 3 times a week for 4 weeks to a total of 12 sessions. BFR cuff (Sports Rehab Tourniquet©) will be used, with a width of 10cm and a length of 116cm or 84cm depending on the diameter of the participants thigh. Therapy sessions will be supervised and in groups. Exercises focus on strengthening the hip extensors and abductors, as well as the quadriceps both in open and closed kinetic chain. Exercises will be carried out using will be set at a load of 30% of 1RM with a limb occlusion pressure (LOP) of 70%. The first set will consist of 30reps. followed by 3 sets of 15reps. at 2:2 (con/ecc) at 60bpm by Metronome app. with auditory cue. Rest between sets will be 30sec and between exercises 2min. Cuffs will be deflated during the resting period between exercises and re-inflated at the beginning of the next exercise. Exercise progression will be individualized based on assessments at the beginning of each week. The duration has been estimated to be approximately 60min. including LOP estimation.; A supervised hip and knee strengthening exercise protocol with a combination of stretching, 3 times a week for 4 weeks to a total of 12 sessions. Exercises focus on hip extensors, abductors, as well as the quadriceps and hamstrings strength. Open Kinetic Chain (OKC) exercises will be executed first followed by CKC exercises. Exercises using weights or mechanical resistance will be set at a load of 70% of 1RM and 3 sets of 10 rep. for each exercise. Elastic band exercises will be set at 10RM for 3 sets. Tempo will be set by the Metronome app installed on a Smartphone at 1:2 (con/ecc) at 60bpm with auditory cue. Rest between sets will be 30sec and between exercises 2min. Exercise progression will be individualized based on assessments at the beginning of each week. The duration of each session is estimated to be approximately 45min, with the exception of the first session of each week which is estimated to be 80min due to the addition of strength testing; Both groups will receive stretching of the hamstrings, plantar flexors, quadriceps and Iliotibial Band (ITB) in the same manor at the end of each session. Passive stretching will be executed by the physiotherapist with 3x30sec stretch for each muscle group
Other intervention name(s): BFR training; Standard treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: This a randomized controlled trial with first primary end point at four weeks and second primary end point at two months. Participants will be allocated randomly into one of two intervention groups. Group1 (Knee and hip focused exercises) Group 2 (knee and hip focused exercises with BFR)
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Patellofemoral Pain; Exercise; Rehabilitation; Blood Flow Restriction training; physical therapy; physiotherapy