Patellofemoral Pain Patients Research Articles

Lower Pressure Pain Thresholds in Patellofemoral Pain Patients, Especially in Female Patients: A Cross-Sectional Case-Control Study.

It has been suggested that repeated overload might sensitize nociceptors, causing local hyperalgesia in patients with patellofemoral pain (PFP). This might also lead to generalized hyperalgesia, indicative of altered central pain processing. This study aimed to investigate differences in pressure pain threshold (PPT) as a measure of pressure hyperalgesia between patients with PFP and healthy controls and in predefined subgroups and to study associations between PPT and patient characteristics. Case-control study. Physiotherapy, general practices, and sports medicine practices. Sixty-four patients with PFP and 70 healthy controls. Demographics, pain (numerical rating score), and function (anterior knee pain score) were obtained by questionnaire. The PPT was measured with a handheld dynamometer with algometry tip at the most painful spot of the affected knee (medial facet in controls), the same spot at the contralateral knee, and at the contralateral forearm. Differences between groups were tested using analysis of variance techniques including the variables age, gender, body mass index, and sports participation. Patients had significantly lower PPTs compared with controls at all locations (affected knee: mean difference = -12.2, 95% confidence interval [CI] = -17.3 to -7.1; contralateral knee: mean difference = -4.7, 95% CI = -10.1 to 0.52; contralateral arm: mean difference = -5.7, 95% CI = -10.5 to -0.8). Both male and female patients demonstrated lower PPTs, though a significant subgroup effect was found for female gender (effect size ranging from 0.73 to 0.98). Local and generalized pressure hyperalgesia, suggesting alterations in both peripheral and central pain processing, were present in patients with PFP, though females with PFP were most likely to suffer from generalized hyperalgesia.

Determination of patellofemoral pain sub-groups and development of a method for predicting treatment outcome using running gait kinematics

BackgroundNot all patients with patellofemoral pain exhibit successful outcomes following exercise therapy. Thus, the ability to identify patellofemoral pain subgroups related to treatment response is important for the development of optimal therapeutic strategies to improve rehabilitation outcomes. The purpose of this study was to use baseline running gait kinematic and clinical outcome variables to classify patellofemoral pain patients on treatment response retrospectively. MethodsForty-one individuals with patellofemoral pain that underwent a 6-week exercise intervention program were sub-grouped as treatment Responders (n=28) and Non-responders (n=13) based on self-reported measures of pain and function. Baseline three-dimensional running kinematics, and self-reported measures underwent a linear discriminant analysis of the principal components of the variables to retrospectively classify participants based on treatment response. The significance of the discriminant function was verified with a Wilk's lambda test (α=0.05). FindingsThe model selected 2 gait principal components and had a 78.1% classification accuracy. Overall, Non-responders exhibited greater ankle dorsiflexion, knee abduction and hip flexion during the swing phase and greater ankle inversion during the stance phase, compared to Responders. InterpretationThis is the first study to investigate an objective method to use baseline kinematic and self-report outcome variables to classify on patellofemoral pain treatment outcome. This study represents a significant first step towards a method to help clinicians make evidence-informed decisions regarding optimal treatment strategies for patients with patellofemoral pain.

The effect of patellar mobilisation on patellar position, pain and knee extensor strength in patellofemoral pain patients

The effect of patellar mobilisation on patellar position, pain and knee extensor strength in patellofemoral pain patients

Correlation between quadriceps to hamstring ratio and functional outcomes in patellofemoral pain

BackgroundThe aim of this study was to investigate the correlation between quadriceps to hamstring (Q:H) ratio and the functional outcomes in Patellofemoral Pain (PFP) patients. MethodsThe study included forty-four women diagnosed with unilateral PFP. Eccentric and concentric quadriceps and hamstring strength were recorded. Conventional Q:H ratio was calculated as the concentric quadriceps to concentric hamstring peak torque (Ratio 1). Functional ratios were calculated as the eccentric quadriceps to concentric hamstring peak torque (Ratio 2) and as the concentric quadriceps to eccentric hamstring torque (Ratio 3). Functional levels of the patients were determined by using Kujala scores, hop test and step test. Pain levels during activities were recorded. The relationship among Ratio 1, Ratio 2 and Ratio 3 with functional outcomes and pain levels were evaluated using Spearman's correlation coefficient test. ResultsEccentric and concentric quadriceps and hamstring strength were lower on involved side than uninvolved side. Ratio 2 correlated stronger with Kujala score (r=0.69) than Ratio 1 (r=0.49) and Ratio 3 (r=0.30). Step test (r=0.35) and hop test (r=0.38) only correlated with Ratio 2. Pain levels correlated more with Ratio 2 (r values ranged between 0.38 and 0.48). ConclusionEccentric quadriceps to concentric hamstring ratio was observed more related to the functional outcomes and painful activities in patients with PFP. Level of evidence IIICross-sectional study.

Are there three main subgroups within the patellofemoral pain population? A detailed characterisation study of 127 patients to help develop targeted intervention (TIPPs)

BackgroundCurrent multimodal approaches for the management of non-specific patellofemoral pain are not optimal, however, targeted intervention for subgroups could improve patient outcomes. This study explores whether subgrouping of non-specific patellofemoral...

Identification of strata for a trial of a targeted multimodal physiotherapy intervention in patellofemoral pain patients

Background Patellofemoral Pain (PFP) is a musculoskeletal disorder causing significant pain and dysfunction around the knee, commonly leading to long term limitations. People with PFP are commonly referred for physiotherapy, although current multimodal physiotherapy approaches tend to be rather ad-hoc and are failing in the long term. Identification of patient strata (or subgroups) who may respond differentially to interventions has been recognised as an international priority. It has been proposed that there are PFP patient strata, classified based on clinical tests, who would respond to modes of interventions targeted at the individual's stratum. Methods Participants with PFP underwent clinical assessment of muscle weakness, muscle length, patellar mobility and foot posture. The presence of strata was explored using two classification techniques: hierarchical cluster analysis and latent profile analysis (LPA); for LPA, the Bayesian Information Criterion was used to guide model selection. Results One hundred and twenty seven (of 130) recruited participants had complete assessment data. A three strata solution appeared optimal from modelling and clinical perspectives. The three suggested strata were characterised as: stronger; weaker and tighter; weaker with pronated feet. However, although membership of the stronger stratum was consistent, there were substantial differences in the other composition of the other two strata between the two classification approaches. Conclusion PFP patients can be classified into clinical strata, although further investigation is needed to identify thresholds upon which stratification should be performed. Interventions are currently being mapped onto the strata and feasibility and evaluation trials of these interventions should then be performed.

FULL WEIGHT BEARING KINEMATIC MRI STUDY OF TT-TG DISTANCE: COMPARING PATIENTS WITH PATELLOFEMORAL PAIN TO HEALTHY INDIVIDUALS

Purpose. The aim of the present study was to investigate tibial tuberosity-trochlear groove (TT-TG) distance dynamics in patients with patellofemoral pain (PFP) and pain free individuals by using full weight bearing kinematic magnetic resonance imaging (MRI) And correlation with patellar instability. Materials and methods. 51 female individuals with PFP and 26 pain free female individuals participated in the study. The kinematic MRI was performed with 1,5 T MRI unit and full-weight bearing. TT-TG distance, bissect offset (BSO) and patellar tilt angle (PTA) were measured in steps of 10° between 50° of flexion to full extension. Results. The TT–TG was higher in PFP patients compared to volunteers’ from 40° to full extension. This difference was statistically significant (p<0.01). PFP patients demonstrated statistically significantly greater TT-TG distance increase from 30° to full extension. BSO and PTA were moderately correlated to TT-TG from 20° of flexion to full extension. Conclusion. TT-TG distance is dynamic and increases significantly during extension in patients with PFP and pain free individuals, depending on knee flexion angle. It shows different pattern of dynamics in PFP group. TT-TG distance is associated with patellar instability (BSO and PTA) at low degrees of flexion.

The effect of foot orthoses on movement patterns during walking and stair decent in normal subjects and patellofemoral pain patients

Background: Patellofemoral pain is a common disorder whose aetiology is complex often being described as multifactorial. It has been suggested that an increased load of the patellofemoral joint could be attributed to foot function and that foot orthoses could be used as a treatment for patellofemoral pain. However, the mechanisms by which foot orthoses work is poorly understood. Therefore there is still a need to develop an understanding of exactly how foot function and foot orthoses affect knee function in patients with patellofemoral pain. Purpose: The aim of this study was to firstly determine if clinically important differences exist in knee kinematics and kinetics between a group of subjects with patellofemoral pain and a group of normal subjects during walking and descending steps. Secondly the study aimed to explore if clinically important changes in foot and knee mechanics could be produced when using two standardised foot orthosis prescriptions. Methods: Fifteen healthy subjects and fifteen subjects with a diagnosis of patellofemoral pain were recruited. All subjects had mild to moderate foot pronation as defined by a score of at least +6 on the foot posture index. All patellofemoral pain subjects scored 3 or more on the numeric pain rating scale when descending stairs. All subjects had ¾ and full length foot orthoses custom fabricated by using a pair of Slimflex™ insoles with a 5 degree medial EVA wedge. Subjects were asked to walk at a self-selected pace and complete a 20 cm step down using the two different orthoses. Kinematic and kinetic data were recorded using 10 Oqus cameras and 4 AMTI force platforms. Reflective markers were placed on the foot, shank and thigh using the Calibrated Anatomical Systems Technique. In addition the patellofemoral pain subjects were ask to rate their pain during the tests. Results: Significant differences were seen between the healthy subjects and patellofemoral pain subjects during both tasks. This included: movement at the midfoot and rearfoot in flexion/extension and inversion/eversion (p = 0.003 to 0.016); movement of the knee joint into flexion, adduction and external rotation (p = 0.003 to 0.016); and in ankle and knee joints moments in dorsiflexion/flexion and adduction (p = 0.012 to 0.035). The foot orthoses produced statistically significant differences in the movement in the forefoot, midfoot and rearfoot across all three planes for both tasks (p = 0.001 to 0.032). The foot orthoses showed no change in the knee kinematics, however both the ¾ and full length foot orthoses produced a significant reduction in the knee adduction moments during step descent (p = 0.019, p = 0.028). Conclusion(s): This study identified potentially clinically important differences between the patellofemoral pain subjects and the normal subjects in the knee mechanics during walking and step down. The foot orthoses also reduced the coronal plane knee moment during the forward continuum phase during step down, which can be associated with a reduction in the medial/lateral loads on the knee joint.

Targeted intervention for patellofemoral pain (TIPPS): psychosocial characteristics of clinical subgroups

Background: Patellofemoral pain (PFP) is a specific musculoskeletal disorder that causes significant pain and dysfunction around the knee cap and knee joint leading to long term limitation in societal participation and physical activity. PFP is a condition commonly referred for physiotherapy intervention, however long term outcomes are poor. We have undertaken a study to explore the presence of clinical subgroups within the PFP population based on the scores of 6 tests that could be used within routine clinical practice. Our research study identified 3 clinical subgroups: Strong subgroup; Weak and Tight subgroup; Pronated feet subgroup. Purpose: There is mounting evidence that factors such as gender and activity levels influence development and outcome in PFP. There is also interest in whether psychosocial factors and different pain mechanisms play a role in determining potential subgroups. Therefore the main objective of this study was to explore interactions between demographic, clinical and psychosocial characteristics and clinical subgroups. Methods: Observational study, at one time point (commencement of physiotherapy). Demographic (Age; Body Mass Index (BMI)), clinical (Time since onset; Patellar skin fold; Tibialis anterior/patella temperature index; Cold Knees questions), and psychosocial characteristics (numeric pain rating scale (NPRS); International physical activity questionnaire (IPAQ); Modified functional index questionnaire (MFIQ); Short Leeds assessment neuropathic sign and symptoms (SLANSS); EQ-5D-5L; Hopkins symptoms check list (HSCL); Movement specific reinvestment scale (MSRS)) were assessed. Differences between the three clinical subgroups were explored using ANOVA, with post hoc tests, or chi-squared tests. Results: Of 127 participants, 66% were female and the mean age was 26 years (SD 5.7), BMI 25.5 (SD 5.8), time since onset 45 months (SD 55) and MFIQ was 34 (SD 17). The strong subgroup had significant higher function, quality of life and there were proportionally more males in this subgroup. The weak and tight subgroup significantly had the highest BMI, and there was a trend towards the lowest levels of activity. The pronated feet subgroup was significantly younger at time of first assessment and there was a trend for higher mean scores for neuropathic pain (SLANSS). There was no difference in mean scores of other characteristics across the subgroups. Conclusion(s): This study, the largest on PFP subgrouping, provides data on other characteristics of PFP patients and suggests significant differences in non-clinical factors between clinical subgroups. The latter provides support for the existence of clinical subgroups and possible insight into potential intervention strategies. For example, higher function and quality of life in the strong subgroup may suggest a focus on movement control is required whereas the higher BMI in the weak and tight subgroup may suggest adjunct weight management strategies may be needed. The neuropathic pain in the pronated feet subgroup may warrant desensitisation interventions. Implications: Demographic and psychosocial characteristics may be important factors to consider in addition to clinical factors in PFP patients. Such factors are increasingly important in managing patients with other musculoskeletal problems. The next step is to understand the relationship between these factors and treatment outcome. Keywords: Patellofemoral pain; Psychosocial; Subgrouping

Targeted intervention for patellofemoral pain (TIPPS): identifying potential clinical subgroups

Background: Patellofemoral pain (PFP) is a specific musculoskeletal disorder that causes significant pain and dysfunction around the knee cap and knee joint, which can lead to long term limitation in societal participation and physical activity. There is a consensus that conservative intervention should be the first treatment option so PFP is a condition that is commonly referred for physiotherapy. Unfortunately, however, current multi modal approaches to intervention in PFP are failing in the long term. Purpose: Given the poor outcome of current treatment regimens, identification of patellofemoral subgroups is an international priority. Large individual variation in outcome results is consistently reported in response to conservative management, therefore understanding whether subgroups have different outcomes has become imperative. However it is unknown whether subgrouping is possible in PFP. The main purpose of this study was to describe the distribution of PFP patients into different subgroups using six routine clinical assessment test criteria. Methods: Design: Cross-sectional with single point assessment prior to commencement of physiotherapy. Participants with PFP underwent clinical assessment of muscle strength (quadriceps and hip abductor), muscle length (quadriceps, hamstrings, gastrocnemius), patellar mobility and foot posture. The presence of subgroups was explored using two classification techniques: Hierarchical Clustering and Latent Profile Analysis. Results: One hundred and twenty seven of 130 recruited participants had complete assessment data: 66% were female, mean (SD) age was 26 (5.7) years, BMI 25.5 (5.8), and Modified Functional Index Questionnaire (MFIQ) was 34 (17). A three subgroup solution appeared optimal from a modelling and clinical perspective. The three suggested clinical subgroups were characterised as: Strong subgroup (n = 44), weak and tight subgroup (n = 58), pronated feet subgroup (n = 25). An ANOVA and post hoc tests confirmed significant differences between subgroups. Strong subgroup: quadriceps strength 1.5 Nm/kg (0.51), hip abductor strength 1.5 Nm/kg (0.51), lowest patellar mobility of the three groups 9.6 mm (3.43). Weak and tight subgroup: hip abductor strength 0.7 Nm/kg (0.27), shortest quadriceps length 118° (17.9). Pronated feet subgroup: highest FPI 7 (3.0), highest patellar mobility 17.6 mm (4.75). Conclusion(s): This study is the largest conducted to date on subgrouping of PFP. The results lend support to the idea that clinical subgroups exist within the patellofemoral population, with three potential subgroups emerging. The key clinical tests for identifying the three subgroups are strength measurement of the quadriceps and hip abductors, and foot posture index. Patellar mobility and quadriceps flexibility contributed to subgroup profiles, so also appear important to consider when identifying PFP subgroups. Implications: These results fit well with other findings in musculoskeletal research where subgrouping has been successful in informing targeted intervention in low back pain patients and is being increasingly adopted as a strategy for managing patients with shoulder problems. Our next step is explore variation in outcome across the identified PFP subgroups and whether subgroup targeted intervention improves overall patient outcomes.

Are Abnormal Proximal Biomechanics Found in Patellofemoral Pain Patients During Running also Evident During Walking?

Are Abnormal Proximal Biomechanics Found in Patellofemoral Pain Patients During Running also Evident During Walking?

Sagittal plane evaluation of patellofemoral movement in patellofemoral pain patients with no evidence of maltracking

The cause of abnormal patellar kinematics in patients with patellofemoral pain remains unclear. Many patients who develop patellofemoral pain symptoms do not exhibit evidence of maltracking. In these patients, sagittal plane evaluation of patellofemoral movement should be performed. Knee radiographs were obtained for forty healthy volunteers and thirty patients at 0°, 30°, 60°, 90° and 120° of flexion in a standing weight-bearing position. The degree of active patellar movement was measured by a newly developed technique called "patellar motion angle". Three independent examiners sequentially performed all of the measurements under identical conditions. A significant decrease in the patellar motion angle was found during deep knee flexion from 90° to 120° in the patient group compared to the volunteer group (mean 18.5°±5.8° and 23.6°±6.2°, respectively) (P=0.001). From 0° to 90° of knee flexion, no significant differences in the patellar motion angle were found between the two groups. Sagittal plane patellofemoral joint kinematics is an area of interest in the study of the mechanical factors associated with patellofemoral pain. This study demonstrated a decrease in patellar movement during deep knee bending activity in patients with patellofemoral pain. Therapeutic study, Level II.

Knee valgus angle during single leg squat and landing in patellofemoral pain patients and controls

BackgroundPatellofemoral pain (PFP) is a commonly presenting disorder of the lower limb, frequently effecting young physically active individuals particularly females. The condition has been associated with poor control of limb alignment while undertaking unilateral limb loading tasks. This poor alignment of the limb is believed to alter loading stress within the patellofemoral joint. This study aims to investigate the degree of knee valgus, assessed as 2D frontal plane projection angle (FPPA) during single leg squatting (SLS) and hop landing (SLL) tasks in patients with PFP and compare their performance to controls and the uninjured limb. MethodTwelve female subjects with unilateral PFP formed the patient group and thirty asymptomatic females formed the control group. They had their 2D frontal plane projection angle (FPPA) assessed during single leg squatting (SLS) and hop landing (SLL) tasks. ResultsIn the asymptomatic control group the mean FPPA for SLS was 8.4±5.1° and SLL had a mean FPPA of 13.5±5.7°. In the PFP group the mean FPPA for SLS was 16.8±5.4° and SLL had a mean FPPA of 21.7+/−3.6°, these differences were significant (p<0.01) for both tasks. ConclusionPatients with PFP have a greater degree of knee valgus on unilateral limb loading task than either their contralateral asymptomatic limb or an asymptomatic control group. If not corrected this may lead to further PFJ stress and ongoing morbidity.

Effect of Patellofemoral Alignment on Conservative Treatment Results

This study shows that the functional outcome after a physical therapy program is not significantly influenced by the presence of PF malalignment. The purpose of this study was to evaluate if different treatment results are observed in patellofemoral pain (PFP) patients with normal and abnormal patellofemoral (PF) alignment. 60 patients underwent an 8-week supervised physical therapy exercise program. Patellofemoral alignment was evaluated in all patients by CT scan with active quadriceps contraction. Malalignment was classified as: a) normal PF alignment (type 0); b) abnormal patellar glide without patellar tilt (type 1); c) normal glide but abnormal tilt (type 2); and d) abnormal tilt and glide (type 3) (Fulkerson & Shea 1990). The Kujala score was recorded as primary outcome measure after the 8-week training program, and at 3 months follow-up. Of the 60 PFP patients, 24 were defined as type 0; 21 patients as type 1; 3 patients as type 2 ; and 12 as type 3. After 8 weeks of physical therapy the type 3 group displays a significant better Kujala score compared to the type 0 group (p=0.042) and the type 1 group (p=0.047). At three months post-treatment, no significant difference between the groups is observed. Statistical analysis reveals a significant improvement of the Kujala score in all three types of PF alignment (p<0.05) after the 8 weeks of physical therapy and at 3 months follow-up. This study shows that the functional outcome after a physical therapy program is not significantly influenced by the presence of PF malalignement. The results of this study may convey the information that the influence PF malalignment on the subjective symptoms in PFPS patients may not be overvalued. This trial provides evidence to support the use of a physical therapy regimen irrespective of the presence of patella malalignment.

The role of muscle strength & activation patterns in patellofemoral pain

BackgroundTo investigate the extent to which quadriceps muscle activation and strength are responsible for patellofemoral pain. MethodsA pain on–off switch system synchronized with a force transducer and surface electromyography was utilized on 32 volunteer patellofemoral pain patients during maximal isometric and squat exercises. FindingsThere were 26 patients out of the 32 tested who complained of pain during the squat or isometric test, of these 20 subjects presented a significant advantage for the vastus lateralis compared to the vastus medialis obliquis activation and 12 patients had decreased quadriceps strength of the symptomatic compared to the non symptomatic leg. All patients who demonstrated weak vastus medialis obliquis activation during the isometric exercise possessed the same symptoms during the squat. On the other hand, 9 patients who showed diminished vastus medialis obliquis activation during the squat displayed equal activation between the vastus medialis obliquis and the vastus lateralis during the isometric task. With regard to the timing for the onset of muscle activation, there were only 4 patients who had a difference (P=0.03) between the symptomatic (0.042s) and non-symptomatic legs (0.011s). InterpretationCauses for patellofemoral pain vary and are not necessarily a result of quadriceps strength deficit or vastus medialis obliquis activation weakness. Patellofemoral pain patients who possess lower vastus medialis obliquis activation compared to the vastus lateralis do not necessarily have quadriceps weakness while patients presenting with quadriceps strength deficits do not always have an imbalance between vastus medialis obliquis and vastus lateralis activation.

Using ultrasound to measure the fibre angle of vastus medialis oblique: A cadaveric validation study

BackgroundThe assumption that the vastus medialis oblique (VMO) is involved in medial patellar stabilisation has led to speculation that patellofemoral pain (PF) may be a result of abnormal patellar tracking, due to weakness or difference in fibre orientation of the VMO. Recent studies have reported that the VMO fibre angle, measured in vivo with ultrasound (US), is reduced in patellofemoral pain (PF) patients. However, the validity of US in measuring this parameter was not investigated and this would inevitably cast doubt on whether the US results are comparable to direct measurement. The aim of this study was to validate the use of ultrasound (US) in measuring VMO fibre angle by comparing results obtained both from US and direct measurement. MethodsThe VMO fibre angle was determined in relation to the femoral axis in nine lower limbs from five soft-fixed cadavers, first using US and then by direct measurement. ResultsThe Pearson correlation coefficient between the two methods was 0.92 (p<0.01) indicating a very strong relationship. The average difference in measurements between the two methods was 0.20. Bland/Altman analysis showed 95% limit of agreement to be between −2.550 and 30, showing minimal discrepancies between results obtained by the two methods. ConclusionIn conclusion, the VMO fibre angle values obtained by the US method were proved to be valid and comparable to those obtained from direct measurement. We show, therefore, that US can be used with confidence to measure VMO fibre angles in the cadaver, and, by implication, in clinical practice.

Comparison of MRI and 18F‐NaF PET/CT in patients with patellofemoral pain

To determine whether bone metabolic activity corresponds to bone and cartilage damage in patients with patellofemoral pain. We acquired magnetic resonance imaging (MRI) and (18) F-NaF positron emission tomography (PET) / computed tomography (CT) scans of the knees of 22 subjects. We compared locations of increased tracer uptake on the (18) F-NaF PET images to bone marrow edema and cartilage damage visualized on MRI. We found that increased bone activity on (18) F-NaF PET does not always correspond to structural damage in the bone or cartilage as seen on MRI. Our results suggest that (18) F-NaF PET/CT may provide additional information in patellofemoral pain patients compared to MRI.

The Effect of Taping, Quadriceps Strengthening and Stretching Prescribed Separately or Combined on Patellofemoral Pain

Quadriceps strengthening, quadriceps stretching and patellar taping are commonly prescribed together for patellofemoral pain patients. This study aimed to examine the effectiveness of each of these techniques in isolation for one week and in combination for one week. A prospective double-blind randomized control study was designed involving 41 subjects with 60 knees diagnosed with patellofemoral pain. The knees were randomized in onto one of four groups (n = 15): infrapatellar taping, quadriceps strengthening, quadriceps stretching and control. The taping was worn continually for the week; the strengthening group followed a programme of non-weight-bearing terminal range quadriceps exercises, the stretching group performed rectus femoris stretches. The control group did not receive treatment. All subjects received advice. Seven pre- and post-treatment measures included isokinetic quadriceps strength, quadriceps length, pain measured during four activities and maximum eccentric, posturally controlled, pain-free knee flexion angle during a step-down. Results showed significant changes over time (p < 0.01) in two out of seven measures for the taping group, in five out of seven for the strengthening group and five out of seven for the stretching group and none in the control group. When the three modalities were combined for one week, (n = 60) all seven measures improved significantly (p < 0.01). In isolation, quadriceps stretching and quadriceps strengthening resulted in more improvements than taping. Combining these treatments is recommended as the initial approach to treating patellofemoral pain but further individualized more functional, global treatment is essential.

A clinical study of the biomechanics of step descent using different treatment modalities for patellofemoral pain

IntroductionIn the previous study we have demonstrated that in healthy subjects significant changes in coronal and transverse plane mechanics can be produced by the application of a neutral patella taping technique and a patellar brace. Recently it has also been identified that patients with patellofemoral pain syndrome (PFPS) display alterations in gait in the coronal and transverse planes. ObjectiveThis study investigated the effect of patellar bracing and taping on the three-dimensional mechanics of the knee of patellofemoral pain patients during a step descent task. MethodThirteen patients diagnosed with patellofemoral pain syndrome performed a slow step descent. This was conducted under three randomized conditions: (a) no intervention, (b) neutral patella taping, (c) patellofemoral bracing. A 20cm step was constructed to accommodate an AMTI force platform. Kinematic data were collected using a ten camera infra-red Oqus motion analysis system. Reflective markers were placed on the foot, shank and thigh using the Calibrated Anatomical System Technique (CAST). ResultsThe coronal plane knee range of motion was significantly reduced with taping (P=0.031) and bracing (P=0.005). The transverse plane showed a significant reduction in the knee range of motion with the brace compared to taping (P=0.032) and no treatment (P=0.046). ConclusionPatients suffering from patellofemoral pain syndrome demonstrated improved coronal plane and torsional control of the knee during slow step descent following the application of bracing and taping. This study further reinforces the view that coronal and transverse plane mechanics should not be overlooked when studying patellofemoral pain.

Patellar Maltracking Correlates With Vastus Medialis Activation Delay in Patellofemoral Pain Patients

Background: Delayed onset of vastus medialis (VM) activity compared with vastus lateralis activity is a reported cause for patellofemoral pain. The delayed onset of VM activity in patellofemoral pain patients likely causes an imbalance in muscle forces and lateral maltracking of the patella; however, evidence relating VM activation delay to patellar maltracking is sparse. The aim of this study was to investigate the relationship between VM activation delay and patellar maltracking measures in pain-free controls and patellofemoral pain patients. Hypothesis: Patellar tilt and bisect offset, measures of patellar tracking, correlate with VM activation delay in patellofemoral pain patients classified as maltrackers. Study Design: Case control study; Level of evidence, 3. Methods: Vasti muscle activations were recorded in pain-free (n = 15) and patellofemoral pain (n = 40) participants during walking and jogging. All participants were scanned in an open-configuration magnetic resonance scanner in an upright weightbearing position to acquire the position of the patella with respect to the femur. Patellar tilt and bisect offset were measured, and patellofemoral pain participants were classified into normal tracking and maltracking groups. Results: Correlations between VM activation delay and patellar maltracking measures were statistically significant in only the patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset (R 2 = .89, P < .001, with patellar tilt during walking; R 2 = .75, P = .012, with bisect offset during jogging). There were no differences between the means of activation delays in pain-free and all patellofemoral pain participants during walking (P = .516) or jogging (P = .731). Conclusion: There was a relationship between VM activation delay and patellar maltracking in the subgroup of patellofemoral pain participants classified as maltrackers with both abnormal tilt and abnormal bisect offset. Clinical Relevance: A clinical intervention such as VM retraining may be effective in only a subset of patellofemoral pain participants—namely, those with excessive tilt and excessive bisect offset measures. The results highlight the importance of appropriate classification of patellofemoral pain patients before selection of a clinical intervention.