Patellofemoral+taping+CPR

__** Patellofemoral Pain Syndrome (PFPS) **__
 * Definitions:**


 * “Anterior knee pain or retro-patellar pain in the absence of other specific pathology. The anatomical source of pain remains a highly debated issue but is commonly believed to be the result of elevated lateral patellofemoral joint (PFJ) stress.” [1]
 * “Variety of pathologies or anatomical abnormalities leading to a type of anterior knee pain that typically occurs with activity and is exacerbated by stair climbing and prolonged sitting.” [3]
 * “…Exacerbated by activities such as stair climbing, prolonged sitting, squatting, and kneeling.” [2]
 * “It is characterized by idiopathic anterior knee pain that is aggravated by deep knee flexion, prolonged sitting and repetitive flexion/extension.” [4]

**Risk factors:**

**Barton et al, 2009 [1]:**
 * Prevalent in adolescents and young adults
 * Patients treated clinically tend to fall between the ages of 18-40 [1]
 * More common in females, but affects both women and men
 * *Relative risk factor because recent randomized control trials have shown “comparative ratios of males to females (44% males) [10], excluding males from evaluation means a large proportion of the PFPS population is not represented.”
 * Altered kinematic theories:
 * Increased hip internal rotation and adduction during gait
 * Increases Q angle and lateral PFJ stress
 * Altered or excessive foot pronation (increase tibial and femoral internal rotation leading to greater adduction or medial collapse of the knee

Paoloni et al, 2010 [3]:

 * Reduced contact area between the femur and patella
 * Leads to increased PFJ stress
 * PFJ neuromuscular control dysfunction [2,4]
 * Significant delay in the electromyographic activation of the vastus medialis obliqus (VMO) compared to the vastus lateralis (VL)
 * Quads provide the most knee stability in the frontal plane and may influence tibial rotation

**Cowan et al, 2001 [2]:**

 * Sporting and general populations that involve repetitive loading of the lower extremity
 * Increased patellofemoral contact pressure due to abnormal lateral tracking of the patella [4]
 * Reduction in the force-producing capabilities of the VMO
 * VMO has a mechanical advantage over the VL due to its oblique fiber orientation
 * VL has a larger cross-sectional area and velocity-producing properties than the VMO that can lead to lateral tracking of the patella.

**//Abnormal gait patterns are commonly seen with PFPS, however, the kinematic changes are still under debate and many different alterations/compensations have been found between different research studies.//**

__** Gait deviations observed in studies: **__ **Barton et al, 2009 [1]:**
 * ~  || Hip || * Decreased hip muscle strength (abductors and external rotators) ||
 * ~  || Knee || * Altered tibiofemoral rotation
 * Increased knee adduction during stance phase of gait
 * Result: lateral patellar tracking and increased lateral PFJ compression ||
 * ~  || Foot || * Excessive pronation theory ||
 * ~  || Spatiotemporal gait || * Reduction in walking velocity, stride length, and cadence
 * Reduction of same characteristics during stair and ramp negotiation
 * Increased support time during running ||
 * ~  || Walking kinematics || * Trends toward earlier and reduced peak hip internal rotation
 * Decreased knee flexion at heel strike and early stance
 * Significant reductions in peak knee flexion
 * Greater rearfoot eversion angle at heel strike transient
 * Delayed timing of peak rearfoot eversion
 * No difference in peak rearfoot eversion or whole foot pronation
 * Increased peak ankle dorsiflexion (limited evidence) ||
 * ~  || Stair and ramp negotiation || * Limited findings indicating no difference in peak hip flexion angle or hip adduction at contralateral foot strike
 * Inconsistent findings related to knee flexion and peak ankle dorsiflexion angles
 * Increased ankle dorsiflexion during both ascent and descent (single study with a medium effect size) ||
 * ~  || Running kinematics || * Inconsistent findings related to hip adduction and internal rotation
 * Increased knee external rotation at peak knee extension moment (limited evidence but potentially significant since this would increase the Q angle and alter PFJ contact area)
 * Greater rearfoot eversion at heel strike (similar findings during walking suggest the foot “may strike the ground in greater rearfoot eversion regardless of the gait activity”
 * Delayed timing of peak rearfoot eversion
 * Reduced range of rearfoot eversion during stance phase ||


 * Foot kinematics while running was taken from a study with a very large number of participants (n = 99 for PFPS group, n = 70 for control group by Duffey et al referenced in this article).
 * Kinematic changes in red were either found in multiple studies or studies with large effect sizes.

Fig. 1. Spatiotemporal gait characteristics (black plots = significant findings with group difference adjacent the right error bar, grey plots = non-significant findings). (A) Gait velocity during walking, stair negotiation and ramp negotiation. (B) Stride length during walking and ramp negotiation. (C) Cadence during walking and ramp negotiation. (D) Running spatiotemporal gait characteristics. (*) Variables were reported to have statistically significant differences between groups in original study. (†) Medium effect sizes found. (‡) Large effect sizes found. Variable abbreviations: M: male, NW: natural walking, F: female FW: fast walking, RA: ramp ascent, SA: stair ascent, RD: ramp descent, SD: stair descent, SL: stride length, SD: stride duration, ST: support time, m: metres, m/s: metres per second, min: minute.

Barton, C. J., Levinger, P., Menz, H. B., & Webster, K. E. (2009). Kinematic gait characteristics associated with patellofemoral pain syndrome: a systematic review. Gait & Posture, 30(4), 405–416.

**Paolini et al, 2010 [3]:**
 * Knee flexion angle at heel contact (HC) || * No significance found ||
 * Knee flexion ROM during loading response (LR) || * No significance found ||
 * Hip and knee abduction peak during LR || * Greater degree of adduction of the knee __(in frontal plane)__ during LR (increased peak knee adduction)
 * Increased hip and knee abductor moments during LR ||
 * Hip and knee rotation ROM during complete gait cycle || * Increased knee external rotator moment with a marked reduction in knee extensor moment during LR (possibly caused by initially isolated VL contraction when VMO activation is delayed) ||
 * Other findings: || * Significantly lower swing phase velocity
 * Significantly lower knee extensor moment in terminal stance (TS)
 * Significantly greater hip abductor moment in TS
 * Significantly lower vertical GRF peak at HC (need to unload the knee joint to avoid pain) ||


 * Reduced swing speed of symptomatic limb
 * Reduces impact ground reaction force (iGRF)
 * Reduces the extensor torque

Table 1. Mean values (SD) of kinematic parameters. Significant differences are in bold. ROM=range of movement; HC=heel contact; LR=loading response. a. Unpaired t-test. b. Mann–Whitney test.
 * || Experimental group || Control group || p ||
 * Knee flexion angle at HC (deg.) || 8.17 (5.15) || 6.78 (7.59) || 0.65 a ||
 * Knee flex-extension ROM during LR (deg.) || 6.62 (4.24) || 6.62 (4.34) || 0.99 a ||
 * Knee adduction peak during LR (deg.) || 2.12 (1.4) || 0.09 (1.5) || 0.009a ||
 * Knee rotation ROM (deg.) || 16.86 (5.9) || 18.73 (8.6) || 0.60 b ||
 * Hip adduction peak during LR (deg.) || 6.42 (3.9) || 6.53 (2.5) || 0.94 b ||
 * Hip rotation ROM (deg.) || 13.04 (5.0) || 11.82 (3.7) || 0.57 b ||

Table 2. Mean values (SD) of kinetic parameters. Significant differences are in bold.   a. Unpaired t-test. b. Mann–Whitney test. c. Unpaired t-test with Welch correction.
 * || Kinetic parameter (Nm/kg) || Experimental group || Control group || p ||
 * Loading response || Hip abductor moment || 0.898 (0.24) || 0.508 (0.17) || 0.001b ||
 * ^  || Hip extensor moment || 0.310 (0.19) || 0.210 (0.12) || 0.20 a ||
 * ^  || Hip external rotator moment || 0.107 (0.03) || 0.09 (0.03) || 0.25 a ||
 * ^  || Knee abductor moment || 0.555 (0.13) || 0.398 (0.13) || 0.01c ||
 * ^  || Knee external rotator moment || 0.071 (0.02) || 0.042 (0.02) || 0.007a ||
 * ^  || Knee extensor moment || 0.027 (0.21) || 0.377 (0.25) || 0.005a ||
 * Terminal stance || Hip abductor moment || 0.842 (0.26) || 0.450 (0.18) || 0.002a ||
 * ^  || Hip flexor moment || −0.378 (0.20) || −0.559 (0.18) || 0.06 a ||
 * ^  || Hip internal rotator moment || −0.138 (0.04) || −0.121 (0.06) || 0.49 a ||
 * ^  || knee abductor moment || 0.477 (0.10) || 0.376 (0.14) || 0.10 a ||
 * ^  || Knee internal rotator moment || −0.075 (0.02) || −0.100 (0.04) || 0.11 a ||
 * || Knee extensor moment || 0.083 (0.06) || 0.329 (0.20) || 0.003a ||
 * || Knee extensor moment || 0.083 (0.06) || 0.329 (0.20) || 0.003a ||

Table 3. Mean values (SD) of ground reaction force (GRF) parameters. For each value the percentage of gait cycle (GC) during which the event occurred is shown. HC=heel contact; LR=loading response; TS=terminal stance; iGRF=impact GRF (see text for clarification). a. Unpaired t-test. b. Mann–Whitney test.   **//Are kinematic changes a result of structural abnormalities or altered kinematics at the joints?//**
 * || Experimental group || % of GC || Control group || % of GC || p ||
 * Vertical force (N/kg) ||  ||   ||   ||   ||   ||
 * Peak at HC (iGRF) || 40.7 (15.6) || 2 || 56.7 (9.1) || 2 || 0.01a ||
 * Peak at LR || 95.5 (25.0) || 16 || 99.8 (6.6) || 17 || 0.63 b ||
 * Peak at TS || 98.2 (23.9) || 46 || 110.6 (8.2) || 47 || 0.17 b ||


 * Reduced walking velocity has been reported to decrease joint motion [1]
 * Interpretation: Kinematic changes can occur due to structural abnormalities or altered kinematics. If cadence and walking speed is controlled, and slowed, joint movements may remain normal. If walking speed stays the same, altered kinematics throughout the lower chain are likely to occur. So it is a trade-off between walking slower or altering joint kinematics.


 * Activation of the quadriceps muscles[2]:**
 * Study by Cowan et al examined the onset of EMG activation of the VMO vs. VL during the functional task of stair stepping
 * Experimental group: n = 33 (11 men, 22 women)
 * Control group: n = 33 (13 men, 20 women)
 * Inclusion criteria for experimental group:
 * Anterior or retropatellar knee pain during 2 or more of the following activities:
 * Prolonged sitting, ascending/descending stairs, squatting, running, kneeling, and hopping/jumping
 * Pain on palpation of the patella
 * Symptoms for > 1 month
 * Average pain level of 3cm on a 10cm visual analog scale
 * Insidious onset of symptoms unrelated to a traumatic incident
 * 40 years of age or younger
 * Reduce likelihood of osteoarthritic changes
 * Procedure:
 * Participants ascended/descended stairs at a rate of 96 steps per minute
 * EMG recordings of VMO and VL muscle activity were recorded during stance phase on the middle stair
 * Results:
 * PFPS subjects reported pain of 2.6 +/- 2cm with stair stepping
 * Control subjects reported no pain
 * EMG onset of VL activation preceded VMO activation in PFPS participants in both ascending (concentric task) and descending (eccentric task) the stairs.
 * EMG onset of VL and VMO activation were almost synchronous in the control group.
 * Consistent with a change in motor control of the quadriceps muscle
 * May be more directly related to PFPS than a change in muscle strength of the quadriceps muscles.

**Limitations presented:**


 * **Barton et al, 2009 [1]:**
 * Lack of prospective studies make it difficult to determine if structural abnormalities, like rearfoot kinematic differences, are risk factors for PFPS or compensations due to already present PFPS.
 * Some studies monitoring foot kinematics only treated the foot as a single segment
 * Difficult to identify whether changes seen where at the talocrural, subtalar, or other joints of the foot.
 * Changes occurring at other foot joints that have a smaller range of motion may have been missed.
 * Yet, PFPS is a common occurrence with runners
 * Inclusion criteria varies significantly between studies (gender, age, assessment tools utilized, joints analyzed vs. entire kinetic chain analyzed during activity, etc…)
 * **Paoloni et al, 2010 [3]:**
 * Low number of participants (n = 9 for both groups)
 * Did not perform an EMG evaluation on the participants, so the theory that the increased knee external rotator moment in LR is due to delayed activation of the VMO and isolated initial contraction of the VL cannot be confirmed.
 * Is the assumption of the article since delayed VMO activation is a common characteristic of PFPS and has been described extensively in literature.
 * **Cowan et al, 2001 [2]:**
 * Cross-sectional design of the study does not allow for the determination of whether the delayed timing of the VMO was a cause of, or result from, knee pain.

**//Sufferers of PFPS are at an increased risk of developing knee osteoarthritis due to abnormal joint motion and repetitive altered knee mechanical loading! [3]//**  References: [1] Barton, C. J., Levinger, P., Menz, H. B., & Webster, K. E. (2009). Kinematic gait characteristics associated with patellofemoral pain syndrome: a systematic review. //Gait & Posture//, //30//(4), 405–416. [2] Cowan, S. M., Bennell, K. L., Hodges, P. W., Crossley, K. M., & McConnell, J. (2001). Delayed onset of electromyographic activity of vastus medialis obliquus relative to vastus lateralis in subjects with patellofemoral pain syndrome. //Archives of Physical Medicine and Rehabilitation//, //82//(2), 183–9. [3] Paoloni, M., Mangone, M., Fratocchi, G., Murgia, M., Saraceni, V. M., & Santilli, V. (2010). Kinematic and kinetic features of normal level walking in patellofemoral pain syndrome: more than a sagittal plane alteration. //Journal of Biomechanics//, //43//(9), 1794–1798. [4] Sheehan, F. T., Borotikar, B. S., Behnam, A. J., & Alter, K. E. (2012). Alterations in in vivo knee joint kinematics following a femoral nerve branch block of the vastus medialis: Implications for patellofemoral pain syndrome. //Clinical Biomechanics//, //27//(6), 2012.

Additional Reading:

Nunes, G. S., Stapait, E. L., Kirsten, M. H., De Noronha, M., & Santos, G. M. (2013). Clinical test for diagnosis of patellofemoral pain syndrome: Systematic review with meta-analysis. //Physical therapy in sport// //: official journal of the Association of Chartered Physiotherapists in Sports Medicine//, //14//(1), 54–9. NLM UID: 100940513

Patellofemoral Taping Overview

 * 3 main functions of patellofemoral taping**

1. Taping assists in pulling the patella away from a painful area; most often, pain is in the anterior knee.

It helps unload the patella, but has not been shown to drastically change its position. Several studies have found that patellofemoral taping does not significantly alter patella location.[4]

One study found that taping does not significantly affect patellar lateralization or tilt, but can help alleviate anterior knee pain.[5]

A systematic review of the effects of patellofemoral taping also highlights the need for further research in order to identify the mechanisms by which taping works.[1]

2. Taping can help increase the proprioceptive characteristics of the patellofemoral joint.[5,2]

Some patellofemoral tracking issues can arise from an imbalance in firing sequence of the quadriceps, specifically regarding the vastus lateralis and the vastus medialis oblique. If the vastus lateralis fires too quickly and is out of sync with the vastus medialis oblique, the patella may be pulled laterally due to the lag between the activation of the two muscles. Therefore, taping across the vastus lateralis may help mediate the lag by reducing overly fast and powerful firing, although how this works is not yet known.[4]More research in this area is needed as one study found that while taping can help decrease pain significantly, EMG measures taken in the study did not show a significant change in vastus lateralis muscle activity with taping.[10]

Taping can also stimulate brain activity in regards to proprioception, and may provide benefit to the patient.[2]

3. One of the main causes of musculoskeletal pain is structural misalignment. Taping may help properly position the patella on the femur so that the amount of contact between the two is correct.[4]

For example, at 20 degrees of knee flexion, the patella should sit midway between the medial and lateral condyles of the femur. If it does not, the patient may experience symptoms in the anterior knee. As stated in the above section, literature on whether or not patellar position can be manipulated with taping varies, and more research is needed in this area.[1]


 * Indications for patellofemoral taping**

Patellofemoral taping is a conservative, non-invasive measure used to treat anterior knee pain, often caused by a patellar tracking issue. It has been shown, in conjunction with therapeutic exercise, to be more effective than use of exercise alone.[12] Of note, one study found that taping is less effective for those with a higher body mass index.[8]

__Q angle__:

The Q angle is the angle given when a line is drawn between the ASIS and mid patella, and the mid patella and tibial tubercle. A wide Q angle can cause the patella to be pulled laterally. Females are more prone to patellofemoral issues due to a broader pelvis and wider Q angle. A wider Q angle can also result from increased femoral internal rotation or increased external rotation of the tibia.

For example, females are more prone to patellofemoral issues due to a broader pelvis and wider Q angle. A wider Q angle can also result from increased femoral internal rotation or increased external rotation of the tibia.

__Improper firing of the quadriceps muscles__:

An overly powerful vastus lateralis may overpower the vastus medialis oblique, and the two muscles may fire out of sync. This causes the patella to be pulled laterally with muscle use and can result in patellofemoral pain syndrome.[ 4,10]

__Fat pad irritation__:

The superior pole of the patella may be taped to help unload the fat pad and assist in decreasing inflammation.[3]

__Patellofemoral pain syndrome__:

Taping can help decrease pain, improve function and muscle strength, and improve overall quality of life; patients may be able to perform more activities with less pain.[7]

__Patellar tendinosis__:

Taping can help stabilize patellar tendon and reduce loading.[9]

__Patellofemoral joint osteoarthritis__:

Research suggests that conservative measures can be used for management of this issue, inclusive of patellofemoral taping. The main effects of taping include pain relief and reduction of the load on the joint. In one study, medial taping for 4 days reduced pain by 25%. More research is needed to determine the mechanism by which this works.[1,6]

One study on isolated patellofemoral osteoarthritis found weak evidence that taping is effective in alleviating pain for patients with this sub classification of knee osteoarthritis.[11]

__Inferior Patellar Tilt__


 * References**


 * 1. ** Aminaka N., Gribble PA. A systematic review of the effects of therapeutic taping on patellofemoral pain syndrome. Journal of Athletic Training. 2005 Oct-Dec;40(4): 341-51. PMID 16404457


 * 2. ** Callaghan MJ., McKie S., Richardson P., Oldham JA. Effects of patellar taping on brain activity during knee joint proprioception tests using functional magnetic resonance imaging. Physical Therapy. 2012 Jun;92(6): 821-30. PMID 22282771


 * 3. ** Dragoo JL., Johnson C,. McConnell J. Evaluation and treatment of disorders of the infrapatellar fat pad. Sports Medicine. 2012 Jan 1;42(1): 51-67. PMID 22149697


 * 4. ** Dutton p 903-904Dutton, M. Dutton’s Orthopaedic Examination, Evaluation, and Intervention. 3rd ed. New York: McGraw Hill Medical; 2012: 903-904.


 * 5. ** Gigante A., Pasquinelli FM., Paladini P., Ulisse S., Greco F. The effects of patellar taping on patellofemoral incongruence. A computed tomography study. American Journal of Sports Med. 2001 Jan-Feb; 29(1): 88-92. PMID: 11206262


 * 6. ** Hinman RS., Crossley KM. Patellofemoral joint osteoarthritis: an important subgroup of knee osteoarthritis. Rheumatology (Oxford). 2007 Jul;46)7): 1057-62. PMID 17500072


 * 7. ** Kuru T., Yaliman A., Dereli EE. Comparison of efficiency of Kinesio taping and electrical stimulation in patients with patellofemoral pain syndrome. Acta Orthopaedica Traumatiol Turc. 2012; 46(5): 385-92. PMID 23268824


 * 8. ** Lan TY., Lin WP., Jiang CC., Chiang H. Immediate effect and predictors of effectiveness of taping for patellofemoral pain syndrome: a prospective cohort study. American Journal of Sports Medicine. 2010 Aug;38(8): 1626-30. PMID 20505056


 * 9. ** Rutland, M., O’Connell, D., Brismee, J.M., Sizer, P., Apte, G., O’Connell, J. (2010). Evidence-supported rehabilitation of patellar tendinopathy. North American Journal of Sports Physical Therapy, 166-178. PMID 21589672


 * 10. ** Salsich GB., Brechter JH., Farwell D., Powers CM. The effects of patellar taping on knee kinetics, kinematics, and vastus lateralis muscle activity during stair ambulation in individuals with patellofemoral pain. Journal of Orthopaedic and Sports Physical Therapy. 2002 Jan;32(1): 3-10. PMID 11787906


 * 11. ** Van Jonbergen HP., Poolman RW., Van Kampen A. Isolated patellofemoral osteoarthritis. Acta Orthopaedica. 2010 Apr;81(2): 199-205. PMID 20175647


 * 12. ** Whittingham M., Palmer S., Macmillan F. Effects of taping on pain and function in patellofemoral pain syndrome: a randomized controlled trial. Journal of Orthopaedic and Sports Physical Therapy. 2004 Sep;34(9): 504-10. PMID 15493518

**Clinical Prediction Rule (CPR) for Patellofemoral Taping**

Lesher JD, Sutlive TG, Miller GA, Chine NJ, Garber MB, Wainner RS. Development of a clinical prediction rule for classifying patients with patellofemoral pain syndrome who respond to patellar taping. J Orthop Sports Phys Ther. 2006 Nov;36(11):854-66.
 * Referenced article:**


 * Overview:**
 * **Type of CPR** || Interventional ||
 * **CPR level** || IV ||
 * **Quality level** || 67% ||
 * **Indicated if** || 1+ predictors present ||
 * **Likelihood Ratio (LR)** || + 4.4 ||
 * **Confidence Interval (CI)** || 95% (1.3-12.3) ||
 * Tests that determine applicability of this CPR**:
 * 1) Tibial varum > 5 degrees
 * 2) Positive patellar tilt test
 * Variable #1:** **Tibial Varum**
 * Ask your patient to stand on an elevated surface, facing away from you.
 * Draw a line that bisects the affected Achilles’ tendon.
 * Measure the angle between the standing surface and the line bisecting the Achilles tendon.
 * This is the angle of tibial varum.
 * If this angle is greater than 5 degrees, this is an indication for use of the patellofemoral taping CPR.

[]

media type="youtube" key="e0o7E5WboVY" height="315" width="560" Patellar tilt test demo: [] Please note a discrepancy: in Appendix B of the Lesher article, a positive test is described as a lateral lift above the horizontal plane; this video depicts a positive test as being a tight retinaculum with no lift above horizontal.
 * Variable #2: Positive Patellar Tilt Test**
 * Ask your patient to lie in the supine position and relax their muscles.
 * Glide the patella passively in a lateral direction.
 * Try to anteriorly lift the lateral aspect of the patella.
 * If the lateral border cannot be lifted above horizontal, this is a positive test.
 * A positive test is an indication for use of patellofemoral taping.

If either of these tests are positive, there is a "small but sometimes clinically important shift in probability" that a patient will benefit in: ...after a patellar taping intervention.
 * Take-Home Message**:
 * Perceived global improvement __and/or__
 * A ≥50% reduction in pain
 * Patellar Taping: The Intervention**
 * Patients were treated for one session
 * Clinicians placed a single piece of leukotape over the lateral aspect of the patella
 * The tape was pulled from lateral to medial

media type="youtube" key="sMJBHBiZjCs" height="315" width="420" Note: The McConnell taping technique was not mentioned in this article, but it is a common taping method that pulls the patella in a lateral to medial direction.

--Military health care beneficiaries --Ages 18-50 --Clinical diagnosis of PFPS (retropatellar pain, provoked with a partial squat or stair ascent/descent) --Fluent in English
 * Criteria** //(Written as it appeared in the study)//
 * Inclusion criteria**

--Abnormal neurological status --Recent hx of knee trauma --Ligamentous laxity of the painful knee --Tenderness of the Join lines or patellar tendon --Prior knee surgery on symptomatic knee --Systemic disease, neurological disease, or connective tissue disease --Additional lower extremity conditions (e.g. stress fractures, shin splints) --Already receiving treatment for knee pain
 * Exclusion criteria**


 * Patient characteristics** //(Written as it appeared in the study)//
 * N = 50 subjects
 * Mean age = 22.8 (+/-4.2)
 * Percentage of subjects defined as a successful outcome = 52%
 * Mean duration of symptoms (days) = 75.4 (+/- 123.8)
 * Gender: female = 46%, male = 54%


 * Definition of Success**
 * ≥ 50% improvement on the composite NPRS of the functional rests (stepping up onto a 20-cm step, stepping down from a 20-cm step, and squatting) or
 * ≥ + 4 (moderately better) on the GROC score


 * Reference:**
 * Lesher JS, Sutlive TG, Miller GA, Chine NJ, Gardber MB, Wainner RS. Development of a clinical prediction rule for classifiying patients with PFPS who respond to patellar taping. J Orthop Sports Phys Ther. 2006; 36:854-866.

Authors Glynn and Weisbach offer considerations when incorporating CPRs into physical therapy practice:
 * Strategies to improve your chances of success when using CPRs:**
 * 1) Consider the details of the CPR before incorporating into your treatment
 * 2) Choose CPRs with high quality scores (this helps eliminate bias from their findings). Interventions with lower quality scores should be used cautiously, if the higher-quality treatment was unsuccessful.
 * 3) Select a CPR for populations similar to your intended patient (review their inclusion and exclusion criteria)
 * 4) Consider the strength of the positive likelihood ratio when prioritizing treatments - use those with higher scores before trying treatments with a lower +LR score.
 * 5) Always test a functional or impairment-based measures before and after an intervention. This test-retest approach provides immediate feedback on the effectiveness of the treatment.

Glynn, Paul E., and P. Cody Weisbach. //Clinical Prediction Rules: A Physical Therapy Reference Manual//. Sudbury, MA: Jones and Bartlett, 2011.
 * Reference**:

Guide to Evidence-Based Physical Therapy Practice[2] Table 13-3 Evidence About Clinical Prediction Rules- Quality Appraisal Checklist (p. 309)

Applied to “Development of a Clinical Prediction Rule for Classifying Patients With Patellofemoral Pain Syndrome Who Respond to Patellar Taping”[1]

Research Validity of the Study

Did the investigators operationally define the sample in their study?


 * Yes
 * Included: military healthcare beneficiaries between 18 and 50 and had a clinical diagnosis of PFPS, fluent in English
 * Excluded: abnormal neurological status, recent history of trauma to the knee, ligamentous laxity of the painful knee, palpation tenderness of the joint lines or patellar tendon, or a history of: prior knee surgery on the symptomatic knee, systemic disease, neurologic disease or connective tissue disease, stress fractures, shin splints, and those already being treated for their knee pain

Were the subjects representative of the population from which they were drawn?


 * Insufficient detail
 * Population was active duty and beneficiary population at Fort Sam Houston. No information about active duty vs. beneficiary and male vs. female ratios in general population vs. study, no information about age of either group.

Did the investigators include all relevant predictive factors in the development process?


 * No: The authors chose the following tests because they are routinely done with knee pain, are measures that guide patellofemoral taping and/or allowed for comparison with previous work
 * Numeric Pain Rating Scale after each three functional tests, Global Rating of Change Questionnaire after the intervention
 * Clinical Measurement Items: Operational Definitions[3]
 * First metatarsophalangeal (MTP) passive extension was measured with the subject sitting and the ankle in neutral (0°) dorsiflexion. The axis of the goniometer was positioned over the joint axis, the stationary arm of the goniometer was positioned over the first metatarsal and the moving arm along the proximal phalanx of the great toe.
 * McConnell test is a provocative test designed to reproduce patellofemoral pain syndrome (PFPS). In a seated position, the examiner placed the symptomatic knee into varying degrees of flexion (0°, 30°, 60°, 90°,120°). At each position, the subject isometrically contracted the quadriceps and held the contraction for 10 seconds. If pain was produced at one of those positions, a second isometric contraction was then performed at the same angle with the patella manually glided medially by the examiner. The test was positive if the subject’s pain was significantly reduced with the patella glided medially.
 * Patellar orientation was visually categorized as medial, neutral, or lateral with the subject seated with both knees flexed to 90°.
 * The Thomas test assessed hip flexor tightness as described by Magee.
 * The hamstring 90-90 test measured hamstring length in supine. The test was considered positive if the subject was unable to extend the symptomatic knee within 20° of full extension.
 * The patellar glide test was used to assess patellar position with the subject supine. The center of the patella was marked, and a tape measure was then placed across the anterior aspect of the knee from the lateral femoral epicondyle to the medial femoral epicondyle. The test was positive if the center of the patella was displaced at least 0.5 cm in either (medial or lateral) direction.
 * The patellar tilt test assessed patellar mobility with the subject supine. With the subject relaxed, the examiner glided the patella laterally and attempted to lift the lateral border of the patella anteriorly. The measurement was recorded as: no lift (negative), lift to neutral (level with a horizontal plane), or lift above (positive) the horizontal plane.
 * The lateral patellar pull test detected any lateral over-pull of the patella by the quadriceps. With the subject supine, the examiner observed the path of the patella as the subject isometrically contracted the quadriceps on the symptomatic side. A positive test was recorded if movement of the patella was greater laterally than superiorly.
 * Ober test assessed iliotibial band tightness with the subject side lying as described by Magee.
 * Craig test assessed the degree of femoral angle of torsion and was performed with the subject prone and the symptomatic knee flexed to 90°.
 * Tibial torsion was measured with the subject prone and the symptomatic knee flexed to 90° as described by Gross.
 * Ankle dorsiflexion active range of motion (AROM) was recorded with the subject prone and the knee extended. Ankle dorsiflexion AROM was also recorded with the knee flexed to 90°.
 * Both subtalar joint neutral (non-weight bearing) and forefoot alignment were measured in the figure-4 position as described by Gross.
 * Relaxed calcaneal stance measured rearfoot alignment with the subject weight bearing as described by Jonson and Gross. The subject stood on a stepstool with the heels flush with the edge of the stool. The degree of deviation of the line that bisected the calcaneus from vertical was recorded.
 * Tibial angulation (varum/valgum) was measured as described by Donatelli. The subject stood on a 20-cm step, and the rater measured the angle formed by the horizontal surface of the step and the line that bisected the Achilles tendon. Tibial varum was defined as the distal end of the tibia being more medial than the proximal end.
 * The navicular drop test was performed in standing as described by Picciano and colleagues.
 * Q-angle was measured with the subject standing as described by Caylor et al. The proximal end of a string was held over the inferior angle of the anterior superior iliac spine (ASIS). The distal end of the string was then taped to the center of the patella and to the tibial tuberosity. The angle of the string formed from the center of the patella to the ASIS, and the center of the patella to the tibial tuberosity was recorded.
 * Pelvic obliquity was measured with the Palpation Meter (PALM). With the subject facing away from the examiner and arms crossed across chest, the PALM was placed over the tops of the iliac crests. The subject was then instructed to inhale deeply and exhale. As the subject held the exhale, the measurement was taken. The PALM calibrated slide rule converted the measurement to centimeters. This measurement was rounded to the nearest centimeter.

Were the predictive factors operationally defined?


 * Yes
 * Appendix B provides the above definitions

Did the investigators include a large enough sample size to accommodate the number of predictive factors used to derive the clinical prediction rule?


 * Yes
 * Although authors stated further studies are needed, for this study, they only needed ten per variable included in the rule once they selected the predictive factors (which are the variables) and 50 in order to do regression.

Were the outcomes of interest operationally defined?


 * Yes
 * An improvement of 50% on the NPRS or 4+ on the GRC qualified the treatment as a success
 * Sensitivity, specificity and likelihood ratios were calculated for each test in Appendix B to determine if it was a predictor of treatment success. Authors cited Jaeschke[1] and colleagues research, stating that +LRs greater than or equal to 2.0 and –LRs less than or equal to 0.5 generate meaningful research.

Were those responsible for measuring the outcomes masked to the status of the predictive factors (and vice versa)?


 * Insufficient detail
 * Authors do not state that the examiners did not know that all of the patients had previously been diagnosed with PFPS or that they did not know the cutoffs for the NPRS/GRC and the status of the predictive factors. However, there were two examiners to verify interrater reliability, to aid in preventing exaggerated results either way.

Did the investigators collect outcome data from all of the subjects enrolled in the study?


 * Yes
 * Results were obtained from all 50 participants. This is expected, as successes were defined as an immediate improvement of 50%, meaning the patients were only seen once.

Do you have enough confidence in the research validity of the paper to consider using this evidence with your patient/client?


 * No
 * The authors stated that a CPR was developed but that validation of the CPR in an independent sample was needed before widespread use was recommended.

Did the investigators compare results from the clinical prediction rule to results from an established criterion test or measure the outcome of interest?


 * No
 * The authors stated that there is currently no published study that shows which tests are predictive of which patients would benefit from patellofemoral taping. Individually, the tests in Appendix B[3] show characteristics of a patient’s body but do not indicate PFPS.

Were all subjects evaluated with the criterion test or measure of the outcome the rule is intended to predict?


 * Yes
 * 26 of the subjects were considered to meet the 50% improvement mark on one of both of the tests, but the tests listed in Appendix B were applied to everyone.

Were the individuals interpreting the results of the clinical prediction rule unaware of the results of the criterion measure and vice versa?


 * No
 * However, the authors stated they were developing a CPR, not verifying a previously described rule. They decided on successful and unsuccessful treatment definitions and predictive likelihood ratios prior to analyzing the results, minimizing bias.

Did the investigators confirm their finding with a new set of subjects?


 * No.
 * Authors stated more research needed to be done on an independent group of subjects.

Has the clinical prediction rule been validated on a population other than the one form which it originally was designed?


 * No.
 * Authors stated that there is no prior published study that develops a CPR for which patients are likely to respond to patellofemoral taping.

Do you have enough confidence in the research validity of this paper to consider using this evidence with your patient/client?


 * No.
 * The authors state that more research needed to be done on an independent group of subjects. Also, the population description was lacking detail and it cannot be determined if it would be representative of patients nationwide.

Relevant Study Findings

Note:
 * Sensitivity: trying to find all of the patients with whom using the CPR to decide in favor of patellar taping on that will have have a positive outcome (will catch some patients where the rule says they will benefit but do not benefit; however, those who the rule says won’t benefit, will not benefit).
 * Specificity: trying to find all of the patient with whom using the CPR rule to decide against patellar taping will not benefit from taping (will find some patients that the rule says won’t benefit when they will, but if the rule says they will benefit, they will benefit)

TABLE 3. Sensitivity, specificity, likelihood ratios (LR), and successful* cutoff scores for the predictors of intervention success (95% confidence intervals shown in parentheses).[3] //These were determined based on the likelihood ratios.//

flexed || 0.53 (0.39-0.67) || 0.75 (0.15-1.35) || 2.1 (0.19-23.7) || 0.63 (0.27-1.5) || ≥15° Patellar tilt || stance || 0.70 (0.50-0.90) || 0.60 (0.42-0.78) || 1.8 (1.0-3.0) || 0.50 (0.24-1.0) || 4° varus ||
 * Predictor of Success || Sensitivity || Specificity || +LR || –LR || Cutoff Score ||
 * Tibial angulation || 0.81 (0.62-1.00) || 0.62 (0.45-0.78) || 2.1 (1.3-3.5) || 0.30 (0.11-0.87) || >5° varus ||
 * Ankle DF with knee
 * Patellar Tilt || 0.88 (0.77-1.00) || 0.51 (0.37-0.65) || 1.8 (1.1-2.9) || 0.24 (0.02-3.3) || Tilt above the horizontal plane ||
 * Relaxed calcaneal

TABLE 4. Validity indices (Sn, Sp, LRs) for the clinical prediction rule (CPR). The 2 items that comprised the CPR were the patellar tilt test and tibial angulation measure. If either item was a positive predictor of treatment success, then the CPR applies with the values shown below. Success defined as an immediate 50% pain reduction or moderate improvement on the Global Rating of Change Scale (95% confidence intervals in parentheses).[3] //The two items (patellar tilt test and tibial angulation measure) were determined by the logistic regression analysis.//

//Side note: In this CPR, if **EITHER** predictor was positive, it predicted success with patellofemoral taping.//


 * Validity Index || Value (Mean[Range]) ||
 * Sensitivity || 0.53 (0.31-0.69) ||
 * Specificty || 0.88 (0.74-1.00) ||
 * +LR || 4.4 (1.3-12.3) ||
 * -LR || 0.530.38-0.86) ||

Back to the Basics:
 * || Positive Results || Negative (or no) results ||
 * Positive CPR || True Positive (test says they will benefit and they do) (sensitivity: 0.53) || False Positive (test says they will benefit and they don’t) ||
 * Negative CPR || False Negative (test says they won’t benefit and they do) || True Negative (test says they won’t benefit and they don’t) (specificity: 0.88) ||

Odds Ratio(s): Not stated

Correlation Coefficients: Not stated

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Statistical significance and/or precision of the relevant study results:


 * Obtained p values for each relevant statistic reported by the authors: 0.15 (larger than usual to avoid excluding possible relevant criteria due to chance)
 * Obtained confidence intervals for each relevant statistic reported by the authors: 95%

If this clinical prediction rule is specific to diagnostic options, does it have criterion validity? It is not specific to diagnostic options.

If this clinical prediction rule is specific to prognostic estimates or plan of care options, does it have predictive validity?


 * Yes
 * In the pretest, 52% of the patients experienced an immediate 50% improvement in symptoms. When the CPR rule was applied, 83% experienced an immediate improvement in symptoms (the rule more successfully selected the patients that would benefit from patellofemoral taping, but caught some false positive as well- good sensitivity)

Application of the Evidence to Your Patient/Client


 * Are there clinically meaningful differences between the subjects in the study and your patient/client?
 * Can you apply the clinical prediction rule safely and appropriately in your clinical setting given your current knowledge and skill level and your current resources?
 * Does the clinical prediction rule fit within the patient/client’s expressed values and preferences?
 * Will you use this clinical prediction rule for this patient/client?

References:


 * 1) Jaeschke R, Guyatt GH, Sackett DL. Users’ guides to the medical literature. III. How to use an article about a diagnostic test. B. What are the results and will they help me in caring for my patients? The Evidence-Based Medicine Working Group. JAMA. 1994;271:703-707.
 * 2) Jewell, Daine V. 2011. Guide to evidence-based physical therapy practice. Sudbury, MA: Jones and Bartlett Learning.
 * 3) Lesher JS, Sutlive TG, Miller GA, Chine NJ, Gardber MB, Wainner RS. Development of a clinical prediction rule for classifiying patients with PFPS who respond to patellar taping. J Orthop Sports Phys Ther. 2006; 36:854-866.

=Wiki Take-Home Points=

PFPS
 * Although the definition for PSPS varies some, anterior or retro-patellar knee pain in the absence of other specific pathologies that is exacerbated during activities like stair climbing, squatting, and prolong sitting are common characteristics of PFPS.
 * The etiology of PFPS is still not fully understood.
 * Some risk factors that have been identified through the literature include: prevalence in those from ages 18-40, potentially more common in females, larger Q-angles, and delayed firing of the VMO muscle compared to the VL muscle.
 * There is a lot of variety in the kinematics of the lower extremity that can cause, or occur from, PFPS.
 * Studies that have analyzed the activity of the VMO and VL muscles in PFPS subjects vs. healthy subjects have reported a delay in EMG activity in the VMO compared to the VL that may cause abnormal lateral tracking of the patella.

Patellofemoral taping
 * Patellofemoral taping is a conservative, non-invasive measure used to treat anterior knee pain, often caused by a patellar tracking issue.
 * It has been shown, in conjunction with therapeutic exercise, to be more effective than use of exercise alone. [Whittingham, et al]
 * Some sources say taping assists in pulling the patella away from a painful area, particularly when pain is in the anterior knee. [Dutton]
 * Patellofemoral taping can help increase the proprioceptive characteristics of the patellofemoral joint. [Callaghan, et al; Gigante, et al]
 * Patellofemoral taping may help position the patella on the femur so that the amount of contact between the two is correct [Dutton], although literature on whether or not patellar position can be manipulated with taping varies.More research is indicated in this area. [Aminaka & Gribble]
 * Common indications for patellofemoral taping include the following: a wider Q angle that may cause tracking issues, improper firing of the quadriceps muscles, fat pad irritation, patellofemoral pain syndrome, patellar tendinosis, patellofemoral joint osteoarthritis, and inferior patellar tilt. [Aminaka & Gribble; Dragoo, et al; Dutton; Hinman& Crossley; Kuru, et al; Rutland, et al; Salsich, et al; Van Jonbergen, et al]
 * More research is needed to determine the mechanisms by which patellofemoral taping works. [Aminaka & Gribble]

Article
 * In patients with tibial varum > 5 degrees AND/OR a positive patellar tilt test, there is a small but important chance that, after patellar taping, the patient will either perceive improvement and/or experience a 50% or greater reduction in pain.
 * This study included military beneficiaries, mean age of 22.8, who had been diagnosed with PFPS with a mean duration of approximately 75 days. This should be considered when applying the CPR in a clinical setting.

Article Critique
 * As far as published research goes, there currently isn't much. The one study available is a preliminary one, with a limited number of subjects and a limited population type. More research is necessary before this CPR can be implemented widely.