Effect of taping the patella on concentric and eccentric torque and EMG of knee extensor and flexor muscles in patients with patellofemoral pain syndrome

Patellofemoral pain syndrome in female athletes: A review of diagnoses, etiology and treatment options

Patellofemoral pain syndrome (PFPS) is one of the most common causes of knee pain and is present in females disproportionately more relative to males. PFPS causes tend to be multifactorial in nature and are described in this review. From a review of the current literature, it is clear that there needs to be further research on PFPS in order to better understand the complex etiology of this disorder in both males and females. It is known that females with patellofemoral pain syndrome demonstrate a decrease in abduction, external rotation and extension strength of the affected side compared with healthy patients. Conservative management, including optimizing muscle balance between the vastus medialis and lateralis around the patella along with formal therapy should be the first line of treatment in patients presenting with PFPS. Surgery should be reserved for patients in which all conservative management options have failed. This review aims to guide physicians in accurate clinicaldecision making regarding conservative and surgical treatment options when specifically faced with PFPS in a female athlete. Furthermore, we will discuss the anatomic variants, incidence and prevalence, etiology, diagnosis and treatment of PFPS.

Anterior knee pain: an update of physical therapy

Anterior knee pain is one of the most common knee problems in physically active individuals. The reason for anterior knee pain has been suggested to be multifactorial with patella abnormalities or extensor mechanism disorder leading to patellar malalignment during flexion and extension of the knee joint. Some patients complain mostly of non-specific knee pain, while others report patellar instability problems. The patients present with a variety of symptoms and clinical findings, meaning that a thorough clinical examination is the key for optimal treatment. Weakness of the quadriceps muscle, especially during eccentric contractions, is usually present in the majority of anterior knee pain patients. However, irrespective of whether pain or instability is the major problem, hypotrophy and reduced activity of the vastus medialis are often found, which result in an imbalance between vastus medialis and vastus lateralis. This imbalance needs to be corrected before quadriceps exercises are started. The non-operative rehabilitation protocol should be divided into different phases based on the patient's progress. The goal of the first phase is to reduce pain and swelling, improve the balance between vastus medialis and vastus lateralis, restore normal gait, and decrease loading of the patello-femoral joint. The second phase should include improvement of postural control and coordination of the lower extremity, increase of quadriceps strength and when needed hip muscle strength, and restore good knee function. The patient should be encouraged to return to or to start with a suitable regular physical exercise. Therefore, the third phase should include functional exercises. Towards the end of the treatment, single-leg functional tests and functional knee scores should be used for evaluating clinical outcome. A non-operative treatment of patients with anterior knee pain should be tried for at least 3 months before considering other treatment options.

Patellar taping for patellofemoral pain syndrome in adults

BACKGROUND

Patellofemoral pain syndrome refers to the clinical presentation of knee pain related to changes in the patellofemoral joint. Patellofemoral pain syndrome usually has a gradual onset of pain with none of the features associated with other knee diseases or trauma. It is often treated by physiotherapists, who use a variety of techniques including patellar taping. This involves the application of adhesive sports medical tape applied directly to the skin over the patella on the front of the knee. Patients often report an instantaneous improvement in pain and function after the tape is applied, but its longer term effects are uncertain.

OBJECTIVES

The objective was to assess the effects, primarily on pain and function, of patellar taping for treating patellofemoral pain syndrome in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, CINAHL, EMBASE, PEDro, SPORTDiscus, AMED, reference lists of articles, trial registers and conference proceedings. All were searched to August 2011.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials testing the effects of patellar taping on clinically relevant outcomes, pain and function, in adults with patellofemoral pain syndrome. We excluded studies testing only the immediate effects of tape application.

DATA COLLECTION AND ANALYSIS

Both review authors independently performed study selection, data extraction and assessment of risk of bias. Trialists were contacted for more information. Data were pooled where possible.

MAIN RESULTS

Five small heterogeneous randomised controlled trials, all at high risk of performance bias and most at risk of at least one other type of bias, were included. These involved approximately 200 participants with a diagnosis of patellofemoral pain syndrome. All compared taping versus control (no or placebo taping) and all included one or more co-interventions given to both taping and control group participants; this was prescribed exercise in four trials. The intensity and length of treatment was very varied: for example, length of treatment ranged from one week in one trial to three months in another. A meta-analysis of the visual analogue scale (VAS) pain data (scale 0 to 10: worst pain), measured in different ways, from four trials (data from 161 knees), found no statistically or clinically significant difference between taping and non taping in pain at the end of the treatment programmes (mean difference (MD) -0.15; 95% confidence interval (CI) -1.15 to 0.85; random-effects model used given the significant heterogeneity (P < 0.0001)). Data for other outcomes measuring function and activities of daily living were from single trials only and gave contradictory results.

AUTHORS' CONCLUSIONS

The currently available evidence from trials reporting clinically relevant outcomes is low quality and insufficient to draw conclusions on the effects of taping, whether used on its own or as part of a treatment programme. Further research involving large, preferably multi-centre, good quality and well reported randomised controlled trials that measure clinically important outcomes and long-term results is warranted. Before this, consensus is required on the diagnosis of patellofemoral pain syndrome, the standardisation of outcome measurement and an acceptable approach for patellar taping.

Comparison of symptoms and clinical findings in subgroups of individuals with patellofemoral pain

Patellofemoral pain syndrome (PFPS) is one of the most common musculoskeletal disorders. However, no consensus on the definition, classification, assessment, diagnosis, or management has been reached. We evaluated symptoms and clinical findings in subgroups of individuals with PFPS, classified on the basis of the findings in radiological examinations and compared the findings with knee-healthy subjects. An orthopedic surgeon and a physical therapist consecutively examined 80 patients clinically diagnosed as having PFPS and referred for physical therapy. The examination consisted of taking a case history and clinical tests. Radiography revealed pathology in 15 patients, and scintigraphic examination revealed focal uptake in 2 patients indicating pathology (group C). Diffusely increased uptake was present in 29 patients (group B). In the remaining 29 patients radiographic and scintigraphic examinations were normal (group A). Knee-healthy controls (group D) reported no clinical symptoms. No symptom could be statistically demonstrated to differ between the three patient groups. Knee-healthy subjects differed significantly from the three patient groups in all clinical tests measuring pain in response to the provocations; compression test, medial and lateral tenderness, passive gliding of the patella, but they also differed in Q angle. Differences in clinical tests between the patient groups were nonsignificant. The main finding in our study on patients clinically diagnosed with PFPS is that possible pathologies cannot be detected from the patient's history or from commonly used clinical tests.

Development of a clinical prediction rule for classifying patients with patellofemoral pain syndrome who respond to patellar taping

STUDY DESIGN

Predictive validity/diagnostic test study.

OBJECTIVE

To determine the predictive validity and interrater reliability of selected clinical exam items and to develop a clinical prediction rule (CPR) to determine which patients respond successfully to patellar taping.

BACKGROUND

Patellar taping is often used to treat patients with PFPS. However, the characteristics of the patients who respond best to patellar taping intervention have not been identified.

METHODS AND MEASURES

Fifty volunteers (27 males, 23 females) with PFPS underwent a standardized clinical examination. Diagnosis of PFPS was based on the complaint of retropatellar pain that was provoked by a partial squat or stair ascent/descent. Subjects performed 3 functional activities and rated their pain during each activity on a numerical rating scale (NPRS). All subjects received treatment with a medial glide patellar-taping technique and repeated the functional activities and pain ratings. An immediate 50% reduction in pain or moderate improvement on a global rating of change (GRC) questionnaire was considered a treatment success. Likelihood ratios (LRs) were calculated to determine which examination items were most predictive of treatment outcome. Logistic regression analysis identified items included in the CPR.

RESULTS

Twenty-six subjects (52%) had an immediate successful response to the intervention. Two examination items (positive patellar tilt test or tibial varum greater than 5 degrees, +LR = 4.4) comprised the CPR. Application of the CPR improved the probability of a successful outcome from 52% to 83%. Fifty-eight percent of the lower extremity measures were associated with moderate to good reliability (reliability coefficient range, 0.52-0.84). The reliability coefficients for the items that comprised the CPR were 0.49 (patellar tilt) and 0.66 (tibial varum).

CONCLUSION

A CPR was developed to predict an immediate successful response to a medial glide patellar taping technique. Validation of the CPR in an independent sample is necessary before widespread clinical use can be recommended.

Clinical classification of patellofemoral pain syndrome: guidelines for non-operative treatment

The patellofemoral pain syndrome (PFPS) remains a challenging musculoskeletal entity encountered by clinicians. Reviewing the literature, conflicting data seem to exist regarding the effect of non-operative treatment in PFPS patients. A possible explanation may be lack of a clear classification system of patients with PFPS. It is our opinion that the term PFPS still is a 'wastebasket', which probably comprises several different entities. Therefore, it seems important to subdivide this broad group of patients into different categories with a specific rehabilitation approach. In this study, we introduce a classification system, which reflects a consensus reached by the European Rehabilitation Panel. This classification system should help the clinicians to identify the cause(s) of patellofemoral pain, and consequently help to select the most appropriate non-operative treatment. The authors are aware that no rehabilitation protocol will work for all PFPS patients, since the underlying mosaic of pathophysiology and tissue-healing responses are unique. Therefore, the aim of this study with a classification system was to guide the clinician through clinical examination in order to develop a non-operative treatment protocol, specific for each individual with PFPS.

Patellar taping increases vastus medialis oblique activity in the presence of patellofemoral pain

A common rehabilitation strategy for patellofemoral pain syndrome (PFPS), which lacks scientific evidence, includes pulling the patella medially with tape to reduce pain and increase the vastus medialis oblique (VMO) muscle activity. The purpose of this study was to examine the effect of various patellar taping procedures on force production, EMG activity of the VMO and vastus lateralis (VL) muscles, and perceived pain experienced by 30 women (27.3 +/- 1.53), half diagnosed with PFPS. The perceived pain, force, and EMG of the VMO and VL, were recorded while subjects performed maximal isokinetic leg presses at 30 degrees /s for each of the following patellar taping conditions: no tape (control), no glide (placebo), medial and lateral glide (experimental). The medial and placebo procedures significantly (P < 0.01) reduced perceived pain (70-80%) in PFPS subjects. Although patellar taping did not influence leg press force (P > 0.05), it increased the VMO activity and decreased the VL activity in PFPS subjects but had the opposite effect in healthy subjects. The findings suggest that taping the patella medially can contribute positively to PFPS rehabilitation. Because the medial glide and placebo taping conditions had similar effects, it is proposed that the benefits of patellar taping are not due to a change in patellar position but rather due to enhanced support of the patellofemoral ligaments and/or pain modulation via cutaneous stimulation.

Medial patellar taping changes the peak plantar force location and timing of female basketball players

Subtle changes in patellofemoral joint biomechanics may influence lower extremity function. The McConnell method of patellar taping has become an increasingly popular method of managing patients with various patellofemoral joint disorders. The purpose of this order effect controlled study was to assess medial patellar taping (McConnell Method) for changes in peak plantar force location and timing while running and dribbling a basketball prior to the performance of a basketball lay-up. Sixteen non-impaired, right hand dominant members of a female junior varsity basketball team (age=14.6 +/- 2 years) participated in this study. Subject bodyweight and height were 607.8 +/- 99 N and 1.67 +/- 0.10 m, respectively. All data were collected from the preferred stance limb. A series of two way analysis of variance (ANOVA) (condition, trial) were used to determine statistical significance (P < or = 0.05). During medial patellar taping, subjects displayed a more forefoot directed peak plantar force location 89.9 +/- 18 versus 81.3 +/- 21 mm and delayed peak plantar force onset 141 +/ - 23 versus 130 +/- 29 ms following initial ground contact. Medial-lateral peak plantar force location and peak plantar force magnitude did not differ between conditions, however, medial-lateral peak plantar force location displayed significant trial sequence influences with the latter trials displaying more lateral center of plantar force locations (30.4 +/- 2 vs. 32.5 +/- 3 mm). The results of this study suggest that medial patellar taping influences distal lower extremity function by shifting peak plantar force location toward the forefoot, and delaying its onset. These changes with consideration for known synergistic ankle plantar flexor-subtalar joint invertor and knee extensor function during weight bearing suggest the presence of increased muscular stiffness acting through a more rigid foot to improve the impact force attenuating capability of the lower extremity.

Which factors predict outcome in the treatment program of anterior knee pain?

The goal of this prospective study was to determine the outcome-predictive role of various parameters in the nonoperative treatment of chronic anterior knee pain patients. Thirty patients followed a five-week treatment program, which consisted out of only closed kinetic chain exercises. Prior to this treatment all subjects were evaluated on muscular characteristics, subjective symptoms, weight, sex, duration of symptoms and functional performance. A multiple stepwise regression analysis revealed that the reflex response time of m. vastus medialis obliquus (VMO) (P=0.041; 0.026), and the duration of symptoms (P=0.019; 0.045) were the only two parameters which were significantly associated with the outcome (evaluated by the Kujala score) at five weeks, and at three months. The shorter the duration of symptoms, or the faster the reflex response time of VMO prior to the treatment, the better the outcome after a closed kinetic chain exercise program. The statistical significance of these parameters in this study may be seen as an indication of the importance of these variables as predictors of the outcome of a closed kinetic chain strengthening program. Using this information, it seems clinically important to begin the treatment program before the anterior knee pain becomes more chronic and treatment results become less good.

The effects of patellar taping on knee kinetics, kinematics, and vastus lateralis muscle activity during stair ambulation in individuals with patellofemoral pain

STUDY DESIGN

Pre- and postintervention repeated measures design.

OBJECTIVE

To determine the effects of patellar taping on knee kinetics, kinematics, and vastus lateralis muscle activity during stair ambulation in individuals with patellofemoral pain (PFP).

BACKGROUND

Patellar taping is a common treatment technique for individuals with PFP. Specific data on whether patellar taping improves gait variables, however, are limited.

METHODS AND MEASURES

Ten subjects with a diagnosis of PFP were studied (five men, five women). The subjects' mean age, height, and mass were 36.5 +/- 11.1 years, 173.1 +/- 10.3 cm, and 70.9 +/- 13.3 kg, respectively. Lower extremity kinematics, ground reaction forces, and vastus lateralis EMG were obtained simultaneously while subjects ascended and descended stairs, under taped and untaped conditions. Knee moments were calculated using inverse dynamics equations. Four 2 x 2 (tape condition x stair condition) ANOVAs for repeated measures were generated for cadence and average stance phase knee extensor moment, knee flexion angle, and EMG.

RESULTS

On the average, a 92.6% reduction in pain was observed following the application of tape. Increases in cadence, knee flexion angles, and knee extensor moments were observed under the taped condition for both stair ascent and descent; however, no difference in average vastus lateralis EMG was found.

CONCLUSIONS

Although patellar taping resulted in decreased pain and increased knee extensor moments, knee flexion angles, and cadence during stair ambulation, the vastus lateralis EMG activity level did not change with taping. Based on data from the vastus lateralis, care must be taken if improved gait parameters indicate change in muscle recruitment.

Failure of voluntary activation of the quadriceps femoris muscle after patellar contusion

STUDY DESIGN

Descriptive study of phenomenon.

OBJECTIVES

To determine the extent of failure of voluntary activation of the quadriceps femoris muscle in patients early after patellar contusion.

BACKGROUND

Pain and effusion are related to the presence of quadriceps inhibition. We hypothesized that patients with patellar contusions would be unable to fully recruit their quadriceps muscles and that the activation deficit would be associated with self-report measures of function.

METHODS AND MEASURES

Sixteen patients who had sustained a unilateral patellar contusion fewer than 4 months prior to testing participated in the study (7 men, 9 women; mean age = 30.0 +/- 11.6). Subjects completed a self-report questionnaire to assess knee function and performed an isometric burst superimposition test on the involved and uninvolved quadriceps at 60 degrees of knee flexion. The subjects were assigned to 2 groups according to the presence (n = 5) or absence (n = 11) of quadriceps inhibition.

RESULTS

Sixty-nine percent of the subjects tested were able to fully activate their quadriceps. Both groups had a decreased knee extensor force on the involved side compared to the uninvolved, but the group with inhibition had a lower side-to-side percentage of knee extensor force (mean = 65.5% +/- 18.9) than those without inhibition (mean = 85.5% +/- 16.4).

CONCLUSION

Early after patellar contusion, approximately one-third of the patients demonstrated quadriceps inhibition. According to our working hypothesis, the majority of the patients tested should have demonstrated inhibition. Quadriceps inhibition was not associated with the activities of daily living, sports activity, or global rating scales in this study. Decreased volitional quadriceps force production (the hallmark of inhibition) was the only variable that discriminated patients with patellar contusion who had inhibition from those who did not.

Patellofemoral pain syndrome: a review of current issues

There is no clear consensus in the literature concerning the terminology, aetiology and treatment for pain in the anterior part of the knee. The term 'anterior knee pain' is suggested to encompass all pain-related problems. By excluding anterior knee pain due to intra-articular pathology, peripatellar tendinitis or bursitis, plica syndromes, Sinding Larsen's disease, Osgood Schlatter's disease, neuromas and other rarely occurring pathologies, it is suggested that remaining patients with a clinical presentation of anterior knee pain could be diagnosed with patello-femoral pain syndrome (PFPS). Three major contributing factors of PFPS are discussed: (i) malalignment of the lower extremity and/or the patella; (ii) muscular imbalance of the lower extremity; and (iii) overactivity. The significance of lower extremity alignment factors and pathological limits needs further investigation. It is possible that the definitions used for malalignment should be re-evaluated, as the scientific support is very weak for determining when alignment is normal and when there is malalignment. Consequently, pathological limits must be clarified, along with evaluation of risk factors for acquiring PFPS. Muscle tightness and muscular imbalance of the lower extremity muscles with decreased strength due to hypotrophy or inhibition have been suggested, but remain unclear as potential causes of PFPS. Decreased knee extensor strength is a common finding in patients with PFPS. Various patterns of weaknesses have been reported, with selective weakness in eccentric muscle strength, within the quadriceps muscle and in terminal knee extension. The significance of muscle function in a closed versus open kinetic chain has been discussed, but is far from well investigated. It is clear that further studies are necessary in order to establish the significance of various strength deficits and muscular imbalances, and to clarify whether a specific disturbance in muscular activation is a cause or an effect (or both) of PFPS. The most common symptoms in patients with PFPS are pain during and after physical activity, during bodyweight loading of the lower extremities in walking up/down stairs and squatting, and in sitting with the knees flexed. However, the source of patellofemoral pain in patients with PFPS cannot be sufficiently explained. There are several types of clinical manifestation of pain, and therefore a differentiated documentation of the patient's pain symptoms is necessary. The connection between strength, pain and inhibition, as well as between personality and pain, needs further investigation. Many different treatment protocols are described in the literature and recent studies advocate a comprehensive treatment approach allowing for an individual and specifically designed treatment. Surgical treatment is rarely indicated. It is strongly suggested that, when presenting studies on PFPS, a detailed description should be provided of the diagnosis, inclusion and exclusion criteria of the patients should be specified along with a detailed methodology, and the conclusions drawn should be compared with those of other studies in the published literature. As this is not the case in most studies on PFPS found in the literature, it is only possible to make general comparisons. In order to further develop treatment models for PFPS we advocate prospective, randomised, controlled, long term studies using validated outcome measures. However, there is a strong need for basic research on the nature and aetiology of PFPS in order to better understand this mysterious syndrome.

Rehabilitation complications following knee surgery

When pain and effusion have been minimized and patients assume appropriate knee posture at rest and during exercise, the extent of postinjury or postoperative quadriceps femoris neuromuscular inhibition and avoidance during locomotion is reduced. Restoring normal lower-extremity ROM and musculotendinous extensibility (with consideration for biarticular muscles) is foundational to the implementation of an exercise program that integrates the trunk, hip, and ankle muscles into dynamic knee-stabilization challenges while addressing isolated quadriceps femoris deficiencies. Cardiovascular conditioning should be addressed as early as feasible. Although programs generally address anaerobic and aerobic energy systems, increasing patients' fatigue resistance, as evidenced by prolonged maintenance of appropriate functional exercise techniques and body control without verbalized discomfort or observed movement-avoidance patterns, ensures therapists that neuromuscular responsiveness for dynamic knee stabilization is improving.