Computational model for the patella onset.

The patella is a sesamoid bone embedded within the quadriceps tendon and the patellar tendon that articulates with the femur. However, how is it formed is still unknown. Therefore, here we have evaluated, computationally, how three theories explain, independently, the patella onset. The first theory was proposed recently, in 2015. This theory suggested that the patella is initially formed as a bone eminence, attached to the anterodistal surface of the femur, while the quadriceps tendon is forming. Thereafter, a joint develops between the eminence and the femur, regulated by mechanical load. We evaluated this theory by simulating the biochemical environment that surrounds the tendon development. As a result, we obtained a patella-like structure embedded within the tendon, especially for larger flexion angles. The second and third theories are the most accepted until now. They state that the patella develops within tendons in response to the mechanical environment provided by the attaching muscles. The second theory analyzed the mechanical conditions (high hydrostatic stress) that (according to previous Carter theories) lead to the differentiation from tendon to fibrocartilage, and then, to bone. The last theory was evaluated using the self-optimizing capability of biological tissue. It was considered that the development of the patella, due to tissue topological optimization of the developing quadriceps tendon, is a feasible explanation of the patella appearance. For both theories, a patella onset was obtained as a structure embedded within the tendon. This model provided information about the relationship between the flexion angle and the patella size and shape. In conclusion, the computational models used to evaluate and analyze the selected theories allow determining that the patella onset may be the result of a combination of biochemical and mechanical factors that surround the patellar tendon development.

Mcconnell's patellar taping does not alter knee and hip muscle activation differences during proprioceptive exercises: A randomized placebo-controlled trial in women with patellofemoral pain syndrome.

The purpose of this study was to assess the effect of patellar taping on muscle activation of the knee and hip muscles in women with Patellofemoral Pain Syndrome during five proprioceptive exercises. Forty sedentary women with syndrome were randomly allocated in two groups: Patellar Taping (based in McConnell) and Placebo (vertical taping on patella without any stretching of lateral structures of the knee). Volunteers performed five proprioceptive exercises randomly: Swing apparatus, Mini-trampoline, Bosu balance ball, Anteroposterior sway on a rectangular board and Mediolateral sway on a rectangular board. All exercises were performed in one-leg stance position with injured knee at flexion of 30° during 15s. Muscle activation was measured by surface electromyography across Vastus Medialis, Vastus Lateralis and Gluteus medius muscles. Maximal voluntary contraction was performed for both hip and knee muscles in order to normalize electromyography signal relative to maximum effort during the exercises. ANOVA results reported no significant interaction (P>0.05) and no significant differences (P>0.05) between groups and intervention effects in all exercise conditions. Significant differences (P<0.01) were only reported between muscles, where hip presented higher activity than knee muscles. Patellar taping is not better than placebo for changes in the muscular activity of both hip and knee muscles during proprioceptive exercises. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02322515.

Normative data of frontal plane patellar alignment in athletes.

OBJECTIVE: The objective of this study was to provide normative data of frontal plane patellar alignment according to McConnell and Arno angles, verify the association between theses angles and identify the presence of patellar rotation in different sports. DESIGN: Cross-sectional. PARTICIPANTS: Nine participants (18 knees) were assessed in a preliminary study to verify the intra and inter-examiner reliabilities of the patellar alignment measures. In the main study, 230 volleyball, basketball, gymnastics and soccer athletes (460 knees) were evaluated in order to obtain normative data of patellar alignment. MAIN OUTCOME MEASURES: Frontal plane patellar alignment (McConnell and Arno angles) measured in standing position by means of photogrammetry. RESULTS: The standardized method demonstrated intra and inter-examiner reliability coefficients varying from .85 to .98. The mean McConnell and Arno angles were 2.05° (±5.9) and 2.89° (±7.57), respectively. A low association was observed (r = .189, p < .0001) between these angles. There was a difference in distribution of medial and lateral rotations, according to the McConnell angle, between different sports (p < .014). CONCLUSIONS: The proposed procedure for measuring patellar alignment according to McConnell and Arno angles proved to be highly reliable. This made possible the establishment of normative data in a large sample of healthy athletes.

Trunk, pelvis, hip, and knee kinematics, hip strength, and gluteal muscle activation during a single-leg squat in males and females with and without patellofemoral pain syndrome.

STUDY DESIGN: Controlled laboratory study using a cross-sectional design. OBJECTIVES: To determine whether there are any differences between the sexes in trunk, pelvis, hip, and knee kinematics, hip strength, and gluteal muscle activation during the performance of a single-leg squat in individuals with patellofemoral pain syndrome (PFPS) and control participants. BACKGROUND: Though there is a greater incidence of PFPS in females, PFPS is also quite common in males. Trunk kinematics may affect hip and knee function; however, there is a lack of studies of the influence of the trunk in individuals with PFPS. METHODS: Eighty subjects were distributed into 4 groups: females with PFPS, female controls, males with PFPS, and male controls. Trunk, pelvis, hip, and knee kinematics and gluteal muscle activation were evaluated during a single-leg squat. Hip abduction and external rotation eccentric strength was measured on an isokinetic dynamometer. Group differences were assessed using a 2-way multivariate analysis of variance (sex by PFPS status). RESULTS: Compared to controls, subjects with PFPS had greater ipsilateral trunk lean (mean ± SD, 9.3° ± 5.3° versus 6.7° ± 3.0°; P = .012), contralateral pelvic drop (10.3° ± 4.7° versus 7.4° ± 3.8°; P = .003), hip adduction (14.8° ± 7.8° versus 10.8° ± 5.6°; P<.0001), and knee abduction (9.2° ± 5.0° versus 5.8° ± 3.4°; P<.0001) when performing a single-leg squat. Subjects with PFPS also had 18% less hip abduction and 17% less hip external rotation strength. Compared to female controls, females with PFPS had more hip internal rotation (P<.05) and less muscle activation of the gluteus medius (P = .017) during the single-leg squat. CONCLUSION: Despite many similarities in findings for males and females with PFPS, there may be specific sex differences that warrant consideration in future studies and when clinically evaluating and treating females with PFPS.

Muscular activity of patella and hip stabilizers of healthy subjects during squat exercises.

BACKGROUND: Hip and knee muscle weaknesses have been associated with the onset of anterior knee pain (AKP). Therefore, the understanding of how squats exercises can be performed in order to optimize the electrical activity of these muscles is relevant for physical therapy treatments. OBJECTIVE: To compare the electromyographic activity of patella and pelvic stabilizers during traditional squat and squat associated with isometric hip adduction or abduction in subjects without AKP. METHODS: Electromyography signals were captured using double-differential electrodes at the vastus medialis obliquus (VMO), vastus lateralis obliquus (VLO), vastus lateralis longus (VLL) and gluteus medium (GMed) in 15 healthy and sedentary women during squats exercises: traditional and associated with hip adduction and hip abduction with load of 25% of body weight. Linear mixed models with significance level of 5% were used for data analysis. RESULTS: Squat associated with hip adduction and abduction produced electromyographic activity of GMed of 0.47 (0.2) and 0.59 (0.22) respectively, while conventional squat produced an electromyiographic activity of 0.33 (0.27). The higher VMO activity was 0.59 (0.27) during the isometric contraction in the squat associated with hip adduction. The higher VLO activity was 0.60 (0.32) during isometric contraction in the squat associated with hip abduction. CONCLUSION: Squat exercise associated with hip adduction increased VMO muscle activity as well as the activity of GMed activity.

Ativação muscular estabilizadora da patela e do quadril durante exercícios de agachamento em indivíduos saudáveis / Muscular activity of patella and hip stabilizers of healthy subjects during squat exercises

CONTEXTUALIZAÇÃO: Atualmente relaciona-se a fraqueza dos músculos do quadril e da coxa ao surgimento da dor anterior no joelho (DAJ). Dessa maneira, compreender como os agachamentos devem ser realizados para melhorar a ativação elétrica desses músculos é importante para o tratamento fisioterapêutico. OBJETIVO: Comparar a ativação mioelétrica de estabilizadores da patela e pelve entre as posições de agachamentos convencional e associado à contração isométrica em adução e abdução da coxa em indivíduos sem queixa de DAJ. MÉTODOS: O sinal eletromiográfico foi captado a partir de eletrodos duplo-diferenciais posicionados nos músculos vasto medial oblíquo (VMO), vasto lateral oblíquo (VLO), vasto lateral longo (VLL) e glúteo médio (GMed) em 15 mulheres sedentárias e clinicamente saudáveis, durante a contração de agachamentos convencional e associados à adução e à abdução isométrica da coxa com carga de 25 por cento do peso corporal. A análise estatística empregada foi o modelo linear de efeitos mistos, com significância de 5 por cento. RESULTADOS: A associação da adução e abdução isométrica da coxa no agachamento produziu cerca de 0,47 (0,2) e 0,59 (0,22), respectivamente, de atividade elétrica do músculo GMed, enquanto o agachamento convencional (AGA) produziu 0,33 (0,27) de atividade elétrica. A maior ativação do VMO aconteceu na contração de agachamento associado à adução da coxa e foi de 0,59 (0,27); já o músculo VLL apresentou uma maior atividade elétrica durante o agachamento associado à abdução, sendo de 0,60 (0,32). CONCLUSÃO: O exercício de agachamento associado à adução da coxa promoveu uma maior ativação muscular do VMO, além de aumentar a atividade muscular do GMed.

BACKGROUND: Hip and knee muscle weaknesses have been associated with the onset of anterior knee pain (AKP). Therefore, the understanding of how squats exercises can be performed in order to optimize the electrical activity of these muscles is relevant for physical therapy treatments. OBJECTIVE: To compare the electromyographic activity of patella and pelvic stabilizers during traditional squat and squat associated with isometric hip adduction or abduction in subjects without AKP. METHODS: Electromyography signals were captured using double-differential electrodes at the vastus medialis obliquus (VMO), vastus lateralis obliquus (VLO), vastus lateralis longus (VLL) and gluteus medium (GMed) in 15 healthy and sedentary women during squats exercises: traditional and associated with hip adduction and hip abduction with load of 25 percent of body weight. Linear mixed models with significance level of 5 percent were used for data analysis. RESULTS: Squat associated with hip adduction and abduction produced electromyographic activity of GMed of 0.47 (0.2) and 0.59 (0.22) respectively, while conventional squat produced an electromyiographic activity of 0.33 (0.27). The higher VMO activity was 0.59 (0.27) during the isometric contraction in the squat associated with hip adduction. The higher VLO activity was 0.60 (0.32) during isometric contraction in the squat associated with hip abduction. CONCLUSION: Squat exercise associated with hip adduction increased VMO muscle activity as well as the activity of GMed activity.

Ultrasonographic study of the femoropatellar joint and its attachments in normal infants from birth to 24 months of age: part I.

Eighty knees of 40 musculoskeletally normal infants whose age ranged from 0 to 24 months (average 9.65 months) were ultrasonographically analyzed. The lengths of the patella, patellar ligament - and the Insall-Salvati index, knee being flexed at 30 degrees , were assessed. The angles of the femoral cartilaginous sulcus knee flexed at 0, 30, 60, and 90 degrees were also defined. Patellar length varied from 1.84 to 2.02 cm (mean, 93.3 cm; standard deviation, 0.35); patellar ligament length varied from 1.67 to 1.86 (mean, 1.76 cm; standard deviation, 0.25); the Insall-Salvati index varied from 1.04 to 1.13, (mean, 1.09; standard deviation, 0.14); and femoral cartilaginous sulcus angle ranged from 148.7 to 149.3 degrees (average, 148.9 degrees and standard deviation, 6.20). Statistical tests showed no significant difference in the proposed measures according to sex and side (right/left). Moreover, we did not observe significant difference in the femoral cartilaginous sulcus angle with respect to the various degrees of knee flexion. Thus, we conclude that ultrasonography is useful for determining the normal values of the Insall-Salvati index and femoral cartilaginous sulcus angle in infants from 0 to 24 months. Then, we suggest standardization of this imaging procedure for the early diagnosis of deformities, which might impair the knee in infants within this range of age.

Efetividade dos exercícios em cadeia cinética aberta e cadeia cinética fechada no tratamento da síndrome da dor femoropatelar / Effectiveness of the open and closed kinetic chain exercises in the treatment of the patellofemoral pain syndrome

O objetivo deste estudo foi analisar os efeitos terapêuticos dos exercícios em cadeia cinética aberta (CCA) e cadeia cinética fechada (CCF) no tratamento da síndrome da dor femoropatelar (SDFP). Para tanto, 24 voluntários portadores de SDFP foram aleatoriamente divididos em dois grupos: grupo I (n = 12): realizou exercícios em CCA; grupo II (n = 12): realizou exercícios em CCF. Os grupos foram submetidos a oito semanas consecutivas de tratamento, que consistiu de três sessões semanais realizadas em dias alternados. Para análise dos padrões de ativação dos músculos vasto medial oblíquo (VMO) e vasto lateral (VL) os sinais eletromiográficos (EMG) foram adquiridos com eletrodos bipolares de superfície, quantificados pela raiz quadrada da média (root mean square RMS) e normalizados pela contração isométrica voluntária máxima do quadríceps. Por meio de escalas avaliou-se a intensidade da dor e funcionalidade dos voluntários. A análise dos valores da razão VMO/VL nos grupos I e II demonstrou que não houve diferenças significativas entre os tempos pré e pós-tratamento nas fases concêntrica (p > 0,05) e excêntrica (p > 0,05) dos exercícios em CCA e CCF. Apesar disso, o músculo VMO apresentou menor taxa de ativação em relação ao VL na fase excêntrica do exercício em CCF. Foram encontrados aumentos significativos na funcionalidade (p < 0,05) e redução da intensidade da dor (p < 0,05) entre os tempos pré e pós-tratamento em ambos os grupos, porém, o grupo II mostrou-se superior ao grupo I nestas duas variáveis. Os resultados deste estudo sugerem que, de acordo com as condições experimentais utilizadas, os exercícios em CCA e CCF não provocaram mudanças nos padrões de ativação EMG dos músculos VMO e VL; entretanto, promoveram melhora da funcionalidade e redução da intensidade da dor após oito semanas de intervenção, sendo que os exercícios em CCF foram superiores aos em CCA.

The aim of this study was to analyze the therapeutic effects of the open kinetic chain (OKC) and closed kinetic chain (CKC) exercises to treat the patellofemoral syndrome (PFSD). For this, 24 volunteers, bearers of the PFSD were randomly divided in two groups: group I (n = 12) performed the OKC exercises; group II (n = 12) performed the CKC exercises. Both groups were submitted to eight consecutive weeks of treatment consisting of three weekly sessions performed in alternate days. To analyze the activation pattern of the vastus medialis oblique (VMO) and the vastus lateralis (VL) muscles, the electromyographic signals (EMG) were collected using bipolar surface electrodes quantified by the root mean square (RMS) normalized by the maximal voluntary isometric contraction of the quadriceps. The pain intensity and the functionality of the volunteers were assessed using scales. The analysis of the amounts of the VMO/VL ratio in both groups I and II showed no significant differences as to the pre- and post-treatment times in the concentric (p > 0.05) and eccentric (p > 0.05) phases of the OKC and CKC exercises. Despite of this, the VMO muscle presented a lower activation rate compared to the VL in the eccentric phase of the CKC exercise. It was found significant increases in the functionality (p < 0.05), and a reduction in the pain intensity (p < 0.05) between the pre- and post-treatment times in both groups, but group II showed higher amounts compared to group I in both variables. The results found in this study suggest that according to the conditions of the trial, the OKC and CKC exercises provoke no changes in the patterns of the EMG activation in the VMO and VL muscles. However, they promoted an improvement in the functionality and a reduction in the pain intensity after the eight week intervention, and the CKC exercises presented better performances than OKC exercises.

El objetivo de este estudio era analizar los efectos terapéuticos de los ejercicios en la cadena cinética abierta (CCA) y la cadena cinética cerrada (CCC) en el tratamiento del síndrome del dolor femoropatelar (SDFP). Para esto se ofrecieron 24 portadores de SDFP que fueron divididos aleatoriamente en dos grupos: Se agruparon en: los ejercicios I en CCA (el n = 12); y los ejercicios II en CCC (el n = 12). Los grupos se sometieron a ocho semanas consecutivas de tratamiento que consistió en tres sesiones semanales logradas en los días alternados. Para los análisis de los modelos de activación de los músculos medio oblicuo (VMO) y vasto lateral (VL) las señales electromiográficas (EMG) adquiridas con los electrodos bipolares de superficie, cuantificaron por la raíz cuadrada del promedio (la raíz el cuadrado - RMS) y se normalizó por el máximo de la reducción isométrico voluntario del cuádriceps. A través de balanzas se evaluó la intensidad del dolor y la funcionalidad de los voluntarios. El análisis de los valores de la razón VMO/VL en los grupos I y II demostramos que no había diferencias significantes entre la veces de tiempos pre y post-tratamiento en las fases concéntricas (el p > 0,05) y excéntricas (el p > 0,05) de los ejercicios en CCA y CCC. A pesar de eso, el músculo VMO presentó un punto de activación más pequeño respecto a VL en la fase excéntrica del ejercicio en CCF. En ellos se encontraron aumentos significantes en la funcionalidad (p < 0,05) y en la reducción de la intensidad del dolor (p < 0,05) entre veces de tiempo y post-tratamiento en ambos grupos, sin embargo, el de grupo II se mostraron superiores al grupo I en estas dos variables. Los resultados de este estudio sugieren que, de acuerdo con las condiciones experimentales usadas, los ejercicios en CCA y CCC no provocaron los cambios en los modelos de activación EMG de los músculos VMO y VL, sin embargo, ellos promovieron mejora de la funcionalidad y reducción de la intensidad...

Indice de compresión patelar inverso: un nuevo parámetro radiológico en el pronóstico de las lesiones de la rodilla / Inverse patellar compression index. A new radiological parameter for the prognosis of the kee injuries

Se recopilan datos radiológicos de las rodillas de 40 individuos deportistas sin antecedentes de traumatismos, malformaciones ni datos patológicos importantes en sus rodillas. Se establece un índice matemático con medidas específicas en las rótula y se encuentra una prevalencia de síntomas rótulo-femorales relacionados con el ejercicio y un índice patelar inverso de menos de 2.8, lo cual puede relacionarse como valor pronóstico en atletas

Patologia femoro patelar: atualizacao de conceitos / Femoropatellar pathology: concept update

Os autores, pela analise da biomecanica do aparelho extensor (ou desacelerador), demonstram as causas das sindromes de instabilidade e hiperpressao femoro-patelar. Em relacao a essas duas entidades clinicas, sao estabelecidos: conceito, diagnostico, classificacao e variacoes clinicas, diagnostico diferencial e metodos de tratamento conservador e cirurgico. Segue-se uma discussao critica das alternativas terapeuticas indicadas previamente.

[Femoropatellar pathology: concept update]. / Patologia fêmoro patelar: atualização de conceitos.

By biomechanical method the extensor mechanism of the knee is analysed, and the causes of instability and hyperpressure in the patello-femoral syndrome are discussed. Concerning these two entities, the author presents: definition, diagnosis, classification, clinical aspects, differential diagnosis, and surgical and clinical treatment.