ProtonicsTM Knee brace has been suggested as an intervention for patients with patellofemoral pain syndrome (PFPS). However, the effectiveness of this knee brace compared to traditional conservative methods knee rehabilitation is lacking. The objective of this randomized controlled trial was to compare the effect of ProtonicsTM knee brace vs. sports cord on knee pain and function in patients with PFPS.
The purpose of this graduate student research study was to compare the effect of ProtonicsTM knee brace vs. sports cord on knee pain and function in patients with PFPS. Design: Randomized controlled trial. Setting: Loma Linda University. Participants: Subjects with patellofemoral pain will participate in the study. Intervention: Subjects will be randomized to one of two treatment groups, the ProtonicsTM knee brace or the sport cord to complete a series of resistance exercises over the course of 4 weeks. Main Outcome Measures: Both groups will be evaluated according to the following clinical outcomes: Anterior pelvic tilt (APT), hip internal/external rotation, and iliotibial band flexibility. The following functional outcomes were also assessed: Global Rating of Change (GROC) scale, the Kujala score, the Numeric Pain Rating Scale, and the lateral step-down test.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
43
The Protonics system has been introduced to physical therapists as a potential treatment for PFPS. The system includes a brace set to resist knee flexion and a set of specific exercises to perform daily. Through resistance to knee flexion, the system is advertised to decrease retropatellar contact pressure due to changes in pelvis inclination and available hip rotation. Specifically, resistance to knee flexion is purported to increase hamstring activity and inhibit the activity of the tensor fasciae latae and psoas muscles. The manufacturer asserts that prolonged use of the system results in greater hamstring activation, which leads to permanent structural changes through reciprocal inhibition at the hip and pelvis. The warm-up consisted of the subject wearing the ProtonicsTM knee brace set at a moderate resistance level and flexing the knees while sitting, standing, and reclining in the supine and prone positions.
Subjects assigned to the sport cord group were asked to do the same warm-ups and exercises using the sport cord in the supine, standing, sitting, and prone positions. prone. The only difference is that subjects were asked to only walk backwards instead of forwards in order to avoid activation of the hip flexor muscle. The appropriate level of resistance for each subject was calculated by multiplying their weight in pounds by 0.3. Subjects were then given either light, medium, or heavy resistance cords according to the following classification scheme: light (pink color) with resistance 3 (R3), 0-30 lbs.; medium (orange color) with resistance 5 (R5) 0-50 lbs.; heavy (yellow color) with resistance 7 (R7) 0-70 lbs. All subjects completed three study visits, and a total of four measurements were taken at baseline, immediately following the first session, at two weeks, and at 4 weeks.
Loma Linda University Health
Loma Linda, California, United States
Anterior Pelvic Tilt
Anterior Pelvic Tilt: tilting of the pelvic will be measured with CHEK inclinometer. Tilting will be measured while subjects are in a standing position. The examiner will determine the two measure line marks, anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) to find the oblique angle of the pelvic. Normative values from other study that we will be using to compare anterior pelvic tilt: Male = 9° and Female = 12° (from Nguyen study in 2007). The CHEK inclinometer caliper has two arms; one arm will be placed on ASIS (front of pelvis) while the other on the PSIS (back of pelvis). The angle of the caliper will be determined to record the degree of anterior pelvic tilt. Baseline measurement to Post-intervention measurement = Four (4) weeks.
Time frame: Baseline to Post intervention
Anterior Pelvic Tilt
Anterior Pelvic Tilt: tilting of the pelvic will be measured with CHEK inclinometer. Tilting will be measured while subjects are in a standing position. The examiner will determine the two measure line marks, anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) to find the oblique angle of the pelvic. Approximate normally anterior pelvic tilt for male is 9° and for female is about 12° (Nguyen, 2007). The caliper has two arms; one arm will be placed on ASIP while the other on the PSIS. The angle of the caliper will be determined to record the degree of anterior pelvic tilt.
Time frame: 2 weeks
Anterior Pelvic Tilt
Anterior Pelvic Tilt: tilting of the pelvic will be measured with CHEK inclinometer. Tilting will be measured while subjects are in a standing position. The examiner will determine the two measure line marks, anterior superior iliac spine (ASIS) and posterior superior iliac spine (PSIS) to find the oblique angle of the pelvic. Approximate normally anterior pelvic tilt for male is 9° and for female is about 12° (Nguyen, 2007). The caliper has two arms; one arm will be placed on ASIP while the other on the PSIS. The angle of the caliper will be determined to record the degree of anterior pelvic tilt.
Time frame: 4 weeks
Numeric Pain Rating Scale (NPRS)
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The Numerical Pain Rating Scale (NPRS) is a subjective measure in which individuals rate their pain on an eleven-point numerical scale. The scale is composed of 0 (no pain at all) to 10 (worst imaginable pain).
Time frame: baseline
Numeric Pain Rating Scale (NPRS)
Used to assess pain level throughout the intervention. Scale: 0-10. Scoring: 0 (no pain) to 10 (worst, imaginable pain).
Time frame: Immediately following 1st session
Numeric Pain Rating Scale (NPRS)
The Numerical Pain Rating Scale (NPRS) is a subjective measure in which individuals rate their pain on an eleven-point numerical scale. The scale is composed of 0 (no pain at all) to 10 (worst imaginable pain).
Time frame: 2 weeks
Numeric Pain Rating Scale (NPRS)
Used to assess pain level throughout the intervention. Scale: 0-10. Scoring: 0 (no pain) to 10 (worst, imaginable pain).
Time frame: 4 weeks
Global Rating of Change (GROC)
GROC scales offer a flexible, quick, and simple method of charting self-assessed clinical progress in research and clinical settings. 15-Point: Scale -7 to 0 to +7. A score of 0 = No change, +1 to +3 = small positive change, +4 to +5 = Moderate positive change, +6 to +7 = Large positive change. All negative scores (minus numbers) represent a poor outcome (-7 being the worst possible outcome).
Time frame: Immediately following 1st session
Global Rating of Change (GROC)
GRC scales offer a flexible, quick, and simple method of charting self-assessed clinical progress in research and clinical settings. It ranges from -7 to 7, in which item -7 represent very great deal worse, 0 represent no change in progress, and 7 exemplify a very great better.
Time frame: 2 weeks
Global Rating of Change (GROC)
GRC scales offer a flexible, quick, and simple method of charting self-assessed clinical progress in research and clinical settings. It ranges from -7 to 7, in which item -7 represent very great deal worse, 0 represent no change in progress, and 7 exemplify a very great better.
Time frame: 4 weeks
Kujala Score
A self-report questionnaire, which is used to evaluate subjective symptoms and functional limitations in subjects with PFPS with a score range between of 0 - 100 based on pain associated with variety of functional activities such as prolonged sitting, squatting, running, and jumping. A score close to 100 indicates a higher functional performance. A score close to 0 represents a low level of function. Kujala scale has shown acceptable test-retest reliability (rho = 0.86) (Paxon et al, 2003). Kujala scale scores will be documented at the beginning and end of the intervention program.
Time frame: baseline
Kujala Score
A self-report questionnaire, which is used to evaluate subjective symptoms and functional limitations in subjects with PFPS with a score range between of 0 - 100 based on pain associated with variety of functional activities such as prolonged sitting, squatting, running, and jumping. A score close to 100 indicates a higher functional performance. Kujala scale has shown acceptable test-retest reliability (rho = 0.86) (Paxon et al, 2003). Kujala scale scores will be documented at the beginning and end of the intervention program.
Time frame: 4 weeks
Lateral Step-Down Test
Lateral step test: is a quick and simple practical clinical measure of functional. Subjects with PFPS will be asked to step up and down on a 15-cm step for 15 seconds each with a cadence of 2 steps per second. The total number of step-ups during this time will be recorded. Subjects will be asked to report a verbal pain score during the step-up test at each test session. This test will be performed every two weeks to document any improvement in the functional performance. The test has shown to be reliable and valid, with test-retest reliability of (ICC = 0.90) (Ross et al, 1997).
Time frame: baseline
Lateral Step-Down Test
Lateral step test: is a quick and simple practical clinical measure of functional. Subjects with PFPS will be asked to step up and down on a 15-cm step for 15 seconds each with a cadence of 2 steps per second. The total number of step-ups during this time will be recorded. Subjects will be asked to report a verbal pain score during the step-up test at each test session. This test will be performed every two weeks to document any improvement in the functional performance. The test has shown to be reliable and valid, with test-retest reliability of (ICC = 0.90) (Ross et al, 1997).
Time frame: Immediately following 1st session
Lateral Step-Down Test
Lateral step test: is a quick and simple practical clinical measure of functional. Subjects with PFPS will be asked to step up and down on a 15-cm step for 15 seconds each with a cadence of 2 steps per second. The total number of step-ups during this time will be recorded. This test will be performed every two weeks to document any improvement in the functional performance. The test has shown to be reliable and valid, with test-retest reliability of (ICC = 0.90) (Ross et al, 1997).
Time frame: 2 weeks
Lateral Step-Down Test
Lateral step test: is a quick and simple practical clinical measure of functional. Subjects with PFPS will be asked to step up and down on a 15-cm step for 15 seconds each with a cadence of 2 steps per second. The total number of step-ups during this time will be recorded. This test will be performed every two weeks to document any improvement in the functional performance. The test has shown to be reliable and valid, with test-retest reliability of (ICC = 0.90) (Ross et al, 1997).
Time frame: 4 weeks
Iliotibial Band Flexibility
To assess the flexibility of iliotibial band
Time frame: baseline
Iliotibial Band Flexibility
To assess the flexibility of iliotibial band
Time frame: Immediately following 1st session
Iliotibial Band Flexibility
To assess the flexibility of iliotibial band
Time frame: 2 weeks
Iliotibial Band Flexibility
To assess the flexibility of iliotibial band
Time frame: 4 weeks
Hip Internal Rotation ROM
To measure the internal rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: baseline
Hip Internal Rotation ROM
To measure the internal rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: Immediately following 1st session
Hip Internal Rotation ROM
To measure the internal rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: 2 weeks
Hip Internal Rotation ROM
To measure the internal rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: 4 weeks
Hip External Rotation ROM
To measure the External rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: baseline
Hip External Rotation ROM
To measure the External rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: Immediately following 1st session
Hip External Rotation ROM
To measure the external rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: 2 weeks
Hip External Rotation ROM
To measure the external rotation of hip in sitting natural position with hip and knee on 90 degree flexion
Time frame: 4 weeks