Patellalgia

Impact of the Quadriceps Angle on Health and Injury Risk in Female Athletes

The quadriceps angle, knowns as the Q-angle, is an anatomical feature of the human body that is still largely unknown and unstudied despite its initial discovery in the 1950s. The strength disparities between male and female athletes are largely determined by the Q-angle. In spite of a growing number of women participating in sports such as track, tennis, soccer, gymnastics, basketball, volleyball, swimming, and softball, studies investigating injuries in this group are scanty. Even though the Q-angle has been the subject of many studies carried out all over the world, a review of the literature regarding its effects on health and injury risk in female athletes has not yet been completed. The aim of this review is to examine the crucial role of the Q-angle in the biomechanics of the knee joint and its effect on performance and injury risk, particularly in female athletes. Furthermore, we highlight the greater likelihood of knee-related injuries seen in female athletes being caused by the Q-angle. Athletes, coaches, healthcare professionals, and athletic trainers can better comprehend and prepare for the benefits and drawbacks resulting from the Q-angle by familiarizing themselves with the research presented in this review.

A Systematic Review on Quadriceps Angle in Relation to Knee Abnormalities

Previous studies on the quadriceps (Q) angle and its relation to knee problems have led to conflicting conclusions. In this comprehensive review, we evaluate recent studies on the Q angle and analyze the changes in Q angles. Specifically, we investigate the variation in Q angles when measured under the following conditions: 1) under various measurement techniques; 2) between symptomatic and non-symptomatic groups; 3) between samples of men and women; 4) unilateral versus bilateral Q angles; 5) Q angle in adolescent boys and girls. It is widely believed that Q angles are more significant in symptomatic patients than in asymptomatic individuals or that the right lower leg and left lower limb are equivalent, which is supported by little scientific data. However, research states that young adult females have higher mean Q angles than males.

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.

Approach to the active patient with chronic anterior knee pain

The diagnosis and management of chronic anterior knee pain in the active individual can be frustrating for both the patient and physician. Pain may be a result of a single traumatic event or, more commonly, repetitive overuse. "Anterior knee pain," "patellofemoral pain syndrome," and "chondromalacia" are terms that are often used interchangeably to describe multiple conditions that occur in the same anatomic region but that can have significantly different etiologies. Potential pain sources include connective or soft tissue irritation, intra-articular cartilage damage, mechanical irritation, nerve-mediated abnormalities, systemic conditions, or psychosocial issues. Patients with anterior knee pain often report pain during weightbearing activities that involve significant knee flexion, such as squatting, running, jumping, and walking up stairs. A detailed history and thorough physical examination can improve the differential diagnosis. Plain radiographs (anteroposterior, anteroposterior flexion, lateral, and axial views) can be ordered in severe or recalcitrant cases. Treatment is typically nonoperative and includes activity modification, nonsteroidal anti-inflammatory drugs, supervised physical therapy, orthotics, and footwear adjustment. Patients should be informed that it may take several months for symptoms to resolve. It is important for patients to be aware of and avoid aggravating activities that can cause symptom recurrence. Patients who are unresponsive to conservative treatment, or those who have an underlying systemic condition, should be referred to an orthopedic surgeon or an appropriate medical specialist.

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.

The diagnostic value of the Clarke sign in assessing chondromalacia patella

CONTEXT

Various techniques have been described for assessing conditions that cause pain at the patellofemoral (PF) joint. The Clarke sign is one such test, but the diagnostic value of this test in assessing chondromalacia patella is unknown.

OBJECTIVE

To (1) investigate the diagnostic value of the Clarke sign in assessing the presence of chondromalacia patella using arthroscopic examination of the PF joint as the "gold standard," and (2) provide a historical perspective of the Clarke sign as a clinical diagnostic test.

DESIGN

Validation study.

SETTING

All patients of one of the investigators who had knee pain or injuries unrelated to the patellofemoral joint and were scheduled for arthroscopic surgery were recruited for this study.

PATIENTS OR OTHER PARTICIPANTS

A total of 106 otherwise healthy individuals with no history of patellofemoral pain or dysfunction volunteered.

MAIN OUTCOME MEASURE(S)

The Clarke sign was performed on the surgical knee by a single investigator in the clinic before surgery. A positive test was indicated by the presence of pain sufficient to prevent the patient from maintaining a quadriceps muscle contraction against manual resistance for longer than 2 seconds. The preoperative result was compared with visual evidence of chondromalacia patella during arthroscopy.

RESULTS

Sensitivity was 0.39, specificity was 0.67, likelihood ratio for a positive test was 1.18, likelihood ratio for a negative test was 0.91, positive predictive value was 0.25, and negative predictive value was 0.80.

CONCLUSIONS

Diagnostic validity values for the use of the Clarke sign in assessing chondromalacia patella were unsatisfactory, supporting suggestions that it has poor diagnostic value as a clinical examination technique. Additionally, an extensive search of the available literature for the Clarke sign reveals multiple problems with the test, causing significant confusion for clinicians. Therefore, the use of the Clarke sign as a routine part of a knee examination is not beneficial, and its use should be discontinued.

Quadriceps EMG in Open and Closed Kinetic Chain Tasks in Women With Patellofemoral Pain

The authors investigated whether the discrepancy noted in the literature regarding delayed and decreased activity in vastus medialis obliquus (VMO) in people with patellofemoral pain (PFP) depends on the nature of the open kinetic chain (OKC) and the closed kinetic chain (CKC) in the experimental task. They hypothesized that activity in VMO would be more delayed and decreased in CKC tasks than in OKC tasks. Women with PFP (n = 17) and healthy controls (n = 17) performed isometric quadriceps contractions in CKC and OKC tasks. The authors manipulated only the application of resistance. Electromyographs (EMGs) showed that participants with PFP reacted later and activated the quadriceps more in the CKC task but had intramuscular quadriceps coordination similar to that of controls. The nature of the OKC task or the CKC task does not seem to explain contradictory findings regarding VMO activation.

Sources of anterior knee pain

The anterior part of the knee consists mainly of structures belonging to the patellofemoral joint, which includes a variety of tissues, such as cartilage, subchondral bone, synovial plicae, infrapatellar fat pad, retinacula, capsule, and tendons. Each of these structures, alone or in combination, can be a source of anterior knee pain. Unphysiologic load or changed metabolic activities can lead to structural failure with loss of homeostatic conditions.

The quadriceps angle: a review of the literature

Previous investigations of the quadriceps (Q) angle and its relationship to knee disorders have yielded equivocal results. The purpose of this paper is to present a review of the current literature on the Q angle and to examine the differences in Q angles when measured: 1) under differing measurement protocols; 2) between asymptomatic and symptomatic populations; 3) between male and female samples; and 4) from side to side within subjects. Little scientific evidence exists to support the commonly held assumptions that Q angles are larger in symptomatic vs. asymptomatic or that they are equal in the right vs. left lower limb. However, larger mean values are consistently observed in groups of young adult females vs. young adult males.

Patellofemoral malalignment

Anterior knee pain represents one of the most common musculoskeletal complaints of adolescents. It is a disorder in which there is broad clinical experience and yet it represents a difficult and frustrating entity for the athlete to endure and for the physician to treat. An appropriate clinical examination and selected diagnostic studies can define the diagnosis and the introduction of conservative therapy usually will correct the problem. Occasionally, surgical intervention is required, and debate remains as to the optimal techniques that should be used.

The relationship between quadriceps angle and anterior knee pain syndrome

Anterior knee pain syndrome (AKPS) represents a significant challenge for patients and for clinicians. The purposes of this study were: 1) to determine the reliability of the Q-angle measurement, 2) to quantify Q-angle changes that occur with knee flexion, and 3) to determine if subjects with AKPS (N = 52) have a significantly different Q-angle than subjects without AKPS (N = 50). With the knee in an extended position, intratester Q-angle intraclass correlation coefficients (ICC) ranged from .84 to .90, and standard error of measurement (SEM) values ranged from 2.01 to 2.23 degrees. Intertester Q-angle ICC was .83, and the SEM was 2.49 degrees. With the knee flexed, the intratester ICC was .83 for both testers, and SEM values ranged from 0.68 to 2.45 degrees. Intertester ICC and SEM were .65 and 3.50 degrees, respectively. No significant difference was found in intratester Q-angle values between the extended and flexed knee positions (p > 0.05). No significant difference in Q-angle was found between asymptomatic subjects (11.1 +/- 5.5 degrees) and symptomatic subjects (12.4 +/- 5.1 degrees) (p = 0.07). Increased Q-angles were not responsible for AKPS in this group of patients. Other factors were hypothesized to be responsible for their symptoms.

Electrical stimulation of vastus medialis and stretching of lateral thigh muscles in patients with patello-femoral symptoms

Thirty patients with unilateral patello-femoral symptoms and a hypotrophic vastus medialis muscle were treated with transcutaneous electrical stimulation of the vastus medialis obliquus and stretching of the lateral thigh muscles twice daily for 10 weeks. Before and after treatment the position of the patella at fixed knee flexion angles and the area of the vastus medialis and vastus lateralis muscles were studied by computed tomography. Isokinetic quadriceps torque was registered with a Cybex II Dynamometer. An evaluation with a functional knee score was carried out. The healthy contralateral leg served as control in all the examinations. Clinically two-thirds of the patients had improved after 10 weeks of treatment and this improvement remained at follow-up 3.5 years later. The area of the vastus medialis and the quadriceps torque of the treated leg increased significantly, while the area of the vastus lateralis and the position of patella did not change. We conclude that transcutaneous electrical muscle stimulation of the vastus medialis and stretching of the lateral thigh muscles might be of benefit in patients with patello-femoral symptoms and a hypotrophic vastus medialis. An improvement after 10 weeks of treatment seems to predict a good long-term result.

Isokinetic quadriceps training in patients with patellofemoral pain syndrome

The aims of the present investigation were (a) to evaluate the effect of eccentric quadriceps training in patients with unilateral patellofemoral pain and (b) to compare the effect of eccentric and concentric quadriceps training in patients with bilateral patellofemoral pain. Fifteen patients (9 male and 6 female, aged 17-36 years with a mean of 27.5 years) participated in this study. Nine patients had unilateral pain and trained their painful leg eccentrically, while six had bilateral pain and trained one leg eccentrically and the other concentrically. Quadriceps muscle training was performed on a Kin-Com dynamometer at 90 degrees/s and 120 degrees/s angular velocity twice a week for 8 weeks. Before and after the treatment period the thigh muscle torques were measured on the Kin-Com dynamometer at 60 degrees/s, 90 degrees/s, 120 degrees/s and 180 degrees/s for quadriceps and at 60 degrees/s and 180 degrees/s for hamstrings. Nine controls, matched for gender and age with the group with unilateral pain, were tested in the same way on the Kin-Com dynamometer. For functional evaluation a knee score was calculated before training, after 8 weeks of training and at a mean of 3.4 years after completion of the training. After 8 weeks of training and at follow-up times of 1 and 3.4 years the patients were also questioned regarding whether or not they felt improvement from the training programme. To determine the degree of knee pain during the training Borg's pain scale was used. The results showed that, compared with the controls, the patients had a significantly lower knee extensor torque in their painful leg at all velocities measured.(ABSTRACT TRUNCATED AT 250 WORDS)

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

The acute effect of patella taping on torque and electromyographic (EMG) activity in maximal voluntary concentric and eccentric action of the knee extensor and flexor muscles in patients with patellofemoral pain syndrome was studied in 48 patients (62 knees). The patients (28 female, 20 male) were tested concentrically and eccentrically on a Kin-Com dynamometer with simultaneous EMG recording with the patella untaped and medially or laterally taped. Patients with clinically normal patellar mobility did not improve their quadriceps performance by taping of the patella; after medial taping they decreased their muscle torque during concentric work at 60 degrees/s (P < 0.05) and eccentric work at 180 degrees/s (P < 0.05). After lateral taping they decreased their muscle torque during concentric work at 60 degrees/s (P < 0.05) and eccentric work at both 60 degrees/s (P < 0.01) and 180 degrees/s (P < 0.05). Moreover, these patients also decreased their agonist EMG activity during concentric work at 60 degrees/s (P < 0.05) and 180 degrees/s (P < 0.05) and their antagonist EMG activity during eccentric work at 60 degrees/s (P < 0.01). Patients with a clinical lateral patellar hypermobility increased their knee extensor torque after medial taping at 60 degrees/s during both eccentric work (P < 0.01) and concentric work (P < 0.05). The greatest improvement in quadriceps performance, however, was in patients with a clinical medial patellar hypermobility. They increased their knee extensor torque after lateral taping during eccentric work at both 60 degrees/s (P < 0.001) and 180 degrees/s (P < 0.001) and during concentric work at 60 degrees/s (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of intraarticular glycosaminoglycan polysulfate treatment on patellofemoral pain syndrome. A prospective, randomized double-blind trial comparing glycosaminoglycan polysulfate with placebo and quadriceps muscle exercises

OBJECTIVE

To compare the effects of intraarticular (IA) injections of glycosaminoglycan polysulfate (GAGPS) plus basic conservative treatment with the effects of placebo injections plus conservative treatment and with the effects of conservative treatment alone in patients with chronic patellofemoral pain syndrome (PFPS).

METHODS

We treated 53 patients who presented with chronic PFPS in 1 knee, according to 1 of the 3 protocols, in a prospective, randomized, double-blind study. Basic conservative treatment consisted of a 6-week program of quadriceps muscle exercise, elimination of symptom-producing activities, and oral doses of nonsteroidal antiinflammatory drugs. Physiologic saline served as placebo for injection. During the 6-week treatment period, 5 injections were given 1 week apart. Along with measurements of quadriceps strength, standardized subjective, functional, and clinical assessments were performed at presentation, after 6 weeks of treatment, and after 6 months.

RESULTS

Results at 6 months indicated that IA injections of GAGPS or saline did not result in significant improvement beyond the good results achieved by the basic conservative treatment alone. More than two-thirds of the patients in each group experienced complete recovery.

CONCLUSION

Neither the GAGPS injections nor the physiologic saline injections are more effective than conservative therapy in the treatment of chronic PFPS. Restoration of normal quadriceps muscle function to the affected knee seems to be crucial in treating PFPS.

Q-angle: a factor in peak torque occurrence in isokinetic knee extension*

* This study was conducted in partial fulfillment for the requirements the U.S. Any-Baylor University Program in Physical Therapy, Academy of Health Sciences, Fort Sam Houston, TX. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the U.S. Army or the Department of the Defense. The purpose of this study was to examine the differences in peak torque occurrence during knee extension range of motion between groups of subjects with varying quadriceps-angle (Q-angle). Fifty-six female subjects, aged 18 to 35, participated in the study. The subjects were separated into three groups: low (N = 12) consisted of subjects with Q-angles <11 degrees ; moderate (N = 27), 13-17 degrees ; and high (N = 17), > 19 degrees . Three sets of subjects, grouped according to Q-angle, were evaluated using the Cybex II Isokinetic Dynamometer. Each subject was tested at three isokinetic speeds (30, 60, and 180 degrees /sec) utilizing only the right lower extremity. The results suggest that the point at which peak torque occurs within knee extension range of motion is not significantly different between the three groups of subjects tested at the three test speeds.J Orthop Sports Phys Ther 1988;9(7):250-253.

Rehabilitation of a collegiate football placekicker with patellofemoral arthritis

A 24-year-old NCAA Division I collegiate football placekicker presented in the clinic 4 months postseason complaining he had begun to experience pain and stiffness in his knee with subsequent loss of power and distance with his kicks toward the latter part of the previous season. He was placed on a rehabilitation program which included utilizing end-range isotonics for the quadriceps, short-arc isokinetics at intermediate speeds, and full range isokinetics at high contractile speeds for knee extension and flexion, lower extremity stretching, electrical stimulation to the quadricep musculature, and underwater kicking workouts along with placekicking and kickoff workouts. The patient was treated in the clinic 3 times per week for 8 weeks and upon discharge subjectively reported having regained distance and power with his kicks. Pre- and post-Cybex testing revealed an increase in peak torque at 60 and 180 degrees /sec of 14 and 15%, respectively, of the quadriceps in the affected kicking leg. This study details one form of intervention in patellofemoral syndrome associated with the specialized sport skill of placekicking.J Orthop Sports Phys Ther 1988:10(6):224-227.

Patellofemoral dysfunction. How to treat, when to refer patients with problematic knees

Patellofemoral dysfunction is a common orthopedic condition. It can be successfully treated by primary care physicians who are familiar with the risk factors, clinical presentation, therapy, and indications for orthopedic referral. Use of a well-tested treatment program can help return most patients to normal function.