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Query: UMLS:C0231749 (knee pain)
 2,815 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To elucidate and attempt to dissociate the two mechanisms, neuromuscular and mechanical, underlying patellofemoral pain syndrome, 18 subjects, divided into two groups based on a diagnosis of patellofemoral pain syndrome and the knee Q angle, were studied. The control group was asymptomatic and exhibited a normal Q angle (mean, 8.25 degrees), whereas the other group, diagnosed as patellofemoral pain syndrome patients, reported knee pain and had an above-normal Q angle (mean, 21.05 degrees). All subjects were tested for isometric maximum knee extension at 90 degrees, 30 degrees, and 15 degrees of knee flexion while they were seated in a special restraining chair. During testing, surface electromyography at the oblique and long fibers of the vastus medialis, and at the vastus lateralis were recorded along with the knee moment of force. The integrated electromyographic signals associated with the peak torque for all of the vastus muscles, along with the vastus medialis obliquus:vastus lateralis and vastus medialis longus:vastus lateralis activity ratios showed no significant differences between groups nor between the three angles, suggesting that all vasti measured were consistently active throughout the studied range of motion. This suggests that the neural drive was not affected in the patellofemoral pain syndrome patients. However, when the five patients showing the largest Q angles were isolated, they revealed a significantly smaller vastus medialis obliquus:vastus lateralis ratio when compared to the other group. The same ratio was also significantly smaller at 15 degrees compared to 90 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Quadriceps femoris muscle activity in patellofemoral pain syndrome. 144 19

Anterior knee pain and overuse sports type injuries have been associated with anatomical factors. Specific diagnosis in knee pain is difficult, most service patients are grouped together as "Patello-Femoral Stress Syndrome". Knee pain incidence within the service population is unknown, but thought to be greater than those presenting to General Practitioners. 293 active duty service men (100 Army and 193 Royal Navy) were interviewed and examined in relation to their knees. 138 measurements were made on each subject. 118 admitted to knee problems. Six had specific diagnoses, ranging from patellar tendonitis to ACL deficiency (with marked anterior instability). The remaining 112 individuals formed the study group and examination findings were compared with the 175 without Patello-Femoral Stress Syndrome. The results have been analysed to determine normal ranges and predictors of knee pain. Age, years in the military and results of patello-femoral compression tests were consistently significantly different between the groups. This survey provides useful information on normal values at examination. Q angle measurement was a poor predictor of knee pain. There was no clinically detectable anatomical variant that correlated with the Patello-Femoral Stress Syndrome. There was poor correlation between Tegner activity score and the perceived limitation on sport or work, as assessed on a visual analogue scale.
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PMID:Association between anatomical features and anterior knee pain in a "fit" service population. 1574 58

Patellar malalignment is the most important reason for anterior knee pain. Patellar alignment is commonly determined by the measurement of the quadriceps (Q) angle. In this study, our primary aim was to investigate the Q angle difference between healthy individuals with and without joint hypermobility. The other objectives were to compare the Q angle values, which were measured in supine and upright positions, to determine hypermobility frequency among healthy males in a certain population, and to investigate the correlation between the existent skeletal deformities and Beighton score levels. Two hundred fifty-three healthy male college students were examined for hypermobility and skeletal deformities. According to the Beighton scoring system, three groups (n=20) were formed, and Q angle measurements were performed on the 60 individuals in both supine and upright positions. In the comparison of the groups, the mean Q angle values in healthy hypermobile individuals were found to be significantly higher than that of the nonhypermobile ones (p<0.05). No statistical difference was found between Q angle values in supine and upright positions (p>0.05). The frequency of joint hypermobility (Beighton score 4 or more) was found to be 29.25% in this population. No correlation was determined between existent skeletal deformities and Beighton score values (p>0.05). In conclusion, the Q angle evaluation among healthy hypermobile individuals may have a prognostic value for probable knee pathologies that may appear in the future.
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PMID:Relationship of Q angle and joint hypermobility and Q angle values in different positions. 1620 28

Knee pain and dysfunction have been often associated with an ineffective pull of the patella by the vastus medialis (VM) relative to the vastus lateralis (VL), particularly in individuals with knee joint malalignment. Such changes in muscular behavior may be attributed to muscle inhibition and/or atrophy that precedes the onset of symptoms. The aim of this study was to investigate possible effects of knee joint malalignment, indicated by a high quadriceps (Q) angle (HQ angle >15 degrees ), on the anatomic cross-sectional area (aCSA) of the entire quadriceps and its individual parts, in a group of 17 young asymptomatic men compared with a group of 19 asymptomatic individuals with low Q angle (LQ angle <15 degrees ). The aCSA of the entire quadriceps (TQ), VM, VL, vastus intermedius (VI), rectus femoris (RF), and patellar tendon (PT) were measured during static and dynamic magnetic resonance imaging (MRI) with the quadriceps relaxed and under contraction, respectively. A statistically significant lower aCSA was obtained in the HQ angle group, compared with the LQ angle group, for the TQ, VL, and VI in both static (TQ = 9.9%, VL = 12.9%, and VI = 9.1%; P < 0.05) and dynamic imaging (TQ = 10.7%, P < 0.001; VL = 13.4%, P < 0.01; and VI = 9.8%, P < 0.05) and the aCSA of the VM in dynamic MRI (11.9%; P < 0.01). The muscle atrophy obtained in the HQ angle group may be the result of a protective mechanism that inhibits and progressively adapts muscle behavior to reduce abnormal loading and wear of joint structures.
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PMID:Quadriceps cross-sectional area changes in young healthy men with different magnitude of Q angle. 1855 37

Patellofemoral pain (PFP) is a frequent cause of anterior knee pain in athletes, which affects patients with and without structural patellofemoral joint (PFJ) damage. Most younger patients do not have any structural changes to the PFJ, such as an increased Q angle and a cartilage damage. This clinical entity is known as patellofemoral pain syndrome (PFPS). Older patients usually present with signs of patellofemoral osteoarthritis (PFOA). A key factor in PFPS development is dynamic valgus of the lower extremity, which leads to lateral patellar maltracking. Causes of dynamic valgus include weak hip muscles and rearfoot eversion with pes pronatus valgus. These factors can also be observed in patients with PFOA. The available evidence suggests that patients with PFP are best managed with a tailored, multimodal, nonoperative treatment program that includes short-term pain relief with nonsteroidal anti-inflammatory drugs (NSAIDs), passive correction of patellar maltracking with medially directed tape or braces, correction of the dynamic valgus with exercise programs that target the muscles of the lower extremity, hip, and trunk, and the use of foot orthoses in patients with additional foot abnormalities.
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PMID:Patellofemoral pain in athletes. 2865 29

The quadriceps angle (Q angle), formed between the quadriceps muscles and the patella tendon, is considered clinically as a very important parameter which displays the biomechanical effect of the quadriceps muscle on the knee, and it is also regarded a crucial factor for the proper posture and movement of the knee patella. The Q angle is routinely and regularly used as an assessment parameter during the diagnosis of many knee-related problems, including the anterior knee pain, osteoarthritis, and degenerative knee disorders. This study had been conducted so as to measure the normal Q angle values range in the Arab nationalities and determine the correlation between Q angle values and several body parameters, including gender, height, weight, dominant side, and the condylar distance of the femur. The study includes 500 healthy young Arab students from the Yarmouk University and Jordan University of Science and Technology. The Q angle of those volunteers was measured using a universal manual Goniometer with the subjects in the upright weight-bearing position. It was found that Q angle was greater in young women than young men. Also, the analysis of the data revealed an insignificant increase in the dominant side of the Q angle. In addition, the Q angle was significantly higher in the taller people of both sexes. However, the Q angle did not present any considerable correlation with weight in the study population; conversely, it was clearly observed that there was a link with the condylar distance of the femur in both sexes. It was also noticed that the Q angle increased remarkably when there was an increase in the condylar distance. Consequently, it turned out that the gender, height, and the condylar distance were momentous factors that had impact on the Q angle in our study samples. However, weight and dominancy factors did not show to have any influence on the values in our study.
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PMID:Measurement of the quadriceps (Q) angle with respect to various body parameters in young Arab population. 3119 51

The medial patellofemoral ligament is the primary static restraint to lateral patellar translation. It is injured in 96% to 100% of patellar dislocations that affect approximately 6 to 29 of 100,000 patients and is more common in patients younger than 20 years of age. Risk factors for patellar dislocation include patella alta, trochlear dysplasia, genu valgus, increased Q angle, and hyperlaxity. The treatment for patellar instability depends on the clinical and radiographic findings and can be nonoperative for first-time dislocations (bracing, proximal strengthening, and progressive return to sport) or operative for recurrent dislocations. It is critical for medial patellofemoral ligament reconstruction to reproduce the anatomy and isometry of the native ligament. Graft choice and methods of fixation are less critical to achieve successful outcomes. Studies have reported successful outcomes and improved Kujala scores, with recurrent instability ranging from 1% to 5%. Careful surgical technique can avoid complications, including fracture, graft failure, loss of range of motion, persistent anterior knee pain, medial instability, and recurrent instability. The role of the medial quadriceps tendon femoral ligament also should be considered more in future research.
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PMID:Medial Patellofemoral Ligament Reconstruction: Indications, Technique, and Outcomes. 3169 43