Tempo de início da atividade elétrica dos estabilizadores patelares na marcha em sujeitos com e sem síndrome de dor femoropatelar / Onset of electromyographic activity of patellar stabilizers during gait in subjects with and without patellofemoral pain syndrome

A síndrome de dor femoropatelar (SDFP) é um problema comum que afeta uma em cadaquatro pessoas. A alteração no tempo de ativação e a intensidade de contração dos músculos vasto medialoblíquo (VMO) e vasto lateral (VL) são consideradas fatores importantes na etiologia da SDFP. No entanto,existem poucos estudos sobre a função da porção oblíqua do vasto lateral (VLO) e nenhum sobre o tempode ativação (onset) do VLO em atividades funcionais em sujeitos normais e com SDFP. Objetivo: Assim, o objetivo do estudo foi investigar o tempo de início de atividade eletromiográfica nos músculos VMO, VLO e VL longo (VLL) durante a marcha. Materiais e métodos: A amostra foi formada por 15 sujeitos sem e 12 comSDFP. Dados eletromiográficos foram obtidos dos músculos VMO, VLL e VLO durante caminhada na esteirasem inclinação. A diferença relativa no onset (DRO) entre VMO-VLL e VMO-VLO foi determinada a partir damédia de três passadas. Resultados: Houve diferença entre os sujeitos com e sem SDFP em relação à DROentre VMO-VLL. Nos sujeitos com SDFP, a ordem de início da atividade elétrica foi VLL seguida por VLO e após VMO. Nos indivíduos sem a patologia, a ordem foi diferente: primeiro VMO após VLO e, por último, VLL. Conclusão: Os achados sugerem que a ativação do VMO após o VLL poderia auxiliar no desenvolvimento ena manutenção da SDFP, enquanto o tempo de ativação do VLO possui menor participação.

INTRODUCTION: The patellofemoral pain syndrome (PFPS) it is a common problem affecting one in each four people. Alteration in the onset time and intensity of contraction of the vastus medialis oblique (VMO) and vastus lateralis (VL) muscles are considered important factors in the aetiology of PFPS. However, few studies exist about the function of the oblique portion of the vastus lateralis (VLO) and none on the onset time of VLO in functional activities in normal subjects and with PFPS.OBJECTIVE: The purpose of this study was to investigate the onset time in the VMO, VLO and VL longus (VLL) muscles during the gait. MATERIALS AND METHODS: Sample was formed by 15 subjects without and 12 with PFPS. Electromyographic data were obtained of the VMO, VLO and VL muscles during treadmill walking with and without inclination. The relative difference in the onset time (DRO) among VMO-VLL and VMO-VLO were determined from the average of 3 strides. Results: There was difference among the subject with and without PFPS in relation to DRO among VMO-VLL. In the subject with PFPS the order at the beginning of the electric activity it was VLL following for VLO and after VMO. In the individuals without the pathology the order was different, first VMO, after VLO and last VLL. CONCLUSION: The findings suggest that the activation of VMO after the one of VLL could aid in the development and maintenance of PFPS, while the time of activation of VLO possesses smaller participation.

Electromyographic and magnetic resonance imaging evaluations of individuals with patellofemoral pain syndrome.

OBJECTIVES: To analyze the electrical activity of the vastus medialis obliquus (VMO), vastus lateralis longus (VLL) and vastus lateralis obliquus (VLO) muscles of individuals with patellofemoral pain syndrome (PFPS) during maximum voluntary isometric contraction (MVIC) of lower leg extension with the knee at 30 degrees; to assess pain using a visual analogue scale (VAS); and to assess patellar positioning using magnetic resonance imaging (MRI). METHODS: Twelve women with PFPS and 12 clinically normal women were evaluated. They performed five MVICs of lower leg extension at 30 degrees for electromyographic (EMG) analysis. Using MRI, the sulcus angle (SA), congruence angle (CA), patellar tilt angle (PTA) and patellar displacement (PD) were obtained. The following statistical tests were used: analysis of variance (ANOVA) for repeated measurements to assess EMGs; Mann-Whitney U test to analyze MRIs; Pearson's (r) correlation test between EMGs and MRIs; and one-way ANOVA to evaluate pain (p < or = 0.05). RESULTS: In the PFPS group, there was greater electrical activity in the VLL than in the VMO. In both groups, there was greater electrical activity in the VMO and VLL than in the VLO. In the PFPS group, the MRI showed higher SA and lower CA values, and there was a negative correlation between the VMO and the PTA. CONCLUSION: The data suggest that, in individuals with PFPS, greater electrical activity in the VLL combined with an increased SA and a decreased CA may contribute to patellar instability.

Avaliação eletromiográfica e ressonância magnética do joelho de indivíduos com síndrome da dor femoropatelar / Electromyographic and magnetic resonance imaging evaluations of individuals with patellofemoral pain syndrome

OBJETIVOS: Analisar a atividade elétrica (EMG) dos músculos vasto medial oblíquo (VMO), vasto lateral longo (VLL) e vasto lateral oblíquo (VLO) de indivíduos com síndrome da dor femoropatelar (SDFP) durante contração isométrica voluntária máxima (CIVM) de extensão da perna com o joelho a 30(0), a dor por meio da Escala Visual Analógica (EVA) e o posicionamento da patela por meio da ressonância magnética nuclear por imagem (RMNI). MÉTODOS: Avaliaram-se 12 mulheres com SDFP e 12 clinicamente normais, que realizaram cinco CIVM de extensão da perna no ângulo de 30(0) para análise da EMG. Avaliou-se o ângulo do sulco (AS), ângulo de congruência (AC), ângulo de inclinação patelar (AIP) e deslocamento patelar (DP) pela RMNI. Utilizaram-se testes estatísticos: ANOVA, análise de variância de medidas repetidas para EMG; o teste Mann-Whitney U para análise da RMNI; o teste de correlação de Pearson (r) entre EMG e RMNI e análise de variância one-way para avaliação da dor (p<0,05). RESULTADOS: Verificou-se maior atividade elétrica do músculo VLL em relação ao VMO no grupo com SDFP. Em ambos os grupos, os músculos VMO e VLL apresentaram maior atividade elétrica que o VLO. Para o grupo SDFP, a RMNI revelou maiores valores do AS e menores do AC, e verificou-se uma correlação negativa entre VMO e AIP. CONCLUSÃO: Os dados sugerem que maior atividade elétrica do VLL, juntamente com o aumento do AS e diminuição do AC, possam ser fatores favorecedores da instabilidade patelar nos indivíduos com SDFP.

OBJECTIVES: To analyze the electrical activity of the vastus medialis obliquus (VMO), vastus lateralis longus (VLL) and vastus lateralis obliquus (VLO) muscles of individuals with patellofemoral pain syndrome (PFPS) during maximum voluntary isometric contraction (MVIC) of lower leg extension with the knee at 30°; to assess pain using a visual analogue scale (VAS); and to assess patellar positioning using magnetic resonance imaging (MRI). METHODS: Twelve women with PFPS and 12 clinically normal women were evaluated. They performed five MVICs of lower leg extension at 30° for electromyographic (EMG) analysis. Using MRI, the sulcus angle (SA), congruence angle (CA), patellar tilt angle (PTA) and patellar displacement (PD) were obtained. The following statistical tests were used: analysis of variance (ANOVA) for repeated measurements to assess EMGs; Mann-Whitney U test to analyze MRIs; Pearson's (r) correlation test between EMGs and MRIs; and one-way ANOVA to evaluate pain (p<0.05). RESULTS: In the PFPS group, there was greater electrical activity in the VLL than in the VMO. In both groups, there was greater electrical activity in the VMO and VLL than in the VLO. In the PFPS group, the MRI showed higher SA and lower CA values, and there was a negative correlation between the VMO and the PTA. CONCLUSION: The data suggest that, in individuals with PFPS, greater electrical activity in the VLL combined with an increased SA and a decreased CA may contribute to patellar instability.

Relação eletromiográfica integrada dos músculos vasto medial oblíquo e vasto lateral longo na marcha em sujeitos com e sem síndrome de dor femoropatelar / Relación electromiográfica integrada de los músculos vasto medial oblicuo y vasto lateral largo en marcha en individuos con y sin síndrome de dolor femoropatelar / Integrated electromyographic ratio of the vastus medialis oblique and vastus lateralis longus muscles in gait in subjects with and without patellofemoral pain syndrome

O objetivo deste estudo foi determinar se existe diferença na ativação dos músculos vasto medial oblíquo (VMO) e vasto lateral longo (VLL) durante a marcha em esteira plana e inclinada a 5° entre sujeitos clinicamente normais e portadores da síndrome da dor femoropatelar (SDFP). Dados eletromiográficos foram obtidos dos músculos VMO e VLL em 15 sujeitos clinicamente normais e em 12 portadores da SDFP. O valor da relação VMO/VLL foi determinado a partir da média de oito passadas, em cada condição, obtidas durante 12s. O teste t de Student mostrou não haver diferença significativa na relação VMO/VLL entre os dois grupos, independente da condição. Apesar de não haver diferença significativa, os sujeitos do grupo controle mostraram maiores valores na relação VMO/VLL, nas duas condições testadas, do que os sujeitos do grupo SDFP. Os achados sugerem que a relação da atividade elétrica dos músculos VMO e VLL, em indivíduos com e sem SDFP, é igual na marcha, tanto em superfície plana como em com inclinação de 5°.

The aim of this study was to determine if there is difference between the vastus medialis oblique and vastus lateralis longus (VMO/VLL) muscles activation during treadmill gait level and ascending to 5 percent degree between healthy subjects and others with patellofemoral pain syndrome. Electromyographic data from the VMO and VLL muscles were obtained in 15 subjects without and 12 with patellofemoral pain syndrome (PFPS) during treadmill gait with and without 5 degrees inclination. The value of the VMO/VLL ratio was determined from the mean of 8 strides, in each condition, during 12 s. The t-Student test did not show significant difference in the VMO/VLL ratio between the two groups, regardless the condition. Although there was not significant difference, the subjects of the control group showed higher values in the VMO/VLL ratio in the two tested conditions than the subject of the PFPS group. The findings suggest that the ratio of the electric activity of the VMO and VLL muscles in individuals with and without SDFP is equal in the gait on flat surface as well as slanted to 5 degrees.

El objetivo de este estudio ha sido determinar si existe diferencia en la activación de los músculos vasto medial oblicuo (VMO) y vasto lateral largo (VLL) durante la caminada en cinta plana ergométrica e inclinada a 5° entre individuos clínicamente normales y portadores de síndrome de dolor femoropatelar (SDFP). Datos electromiográficos se obtuvieron de los músculos VMO y VLL en 15 sujetos clínicamente normales y 12 portadores de SDFP. El valor de la relación VMO/VLL se determinó a partir de la media de 8 pasadas, a cada condición, durante 12 s. El test t de Student mostró que no hay diferencia significativa en la relación VMO/VLL entre los dos grupos, independiente de la condición. A pesar de no haber diferencia significativa, los integrantes del grupo control mostraron mayores valores en VMO/VLL, durante las dos condiciones probadas que los del grupo SDFP. Los hallazgos sugieren que la relación de actividad eléctrica de los músculos VMO y VLL, en individuos con y sin SDFP es igual en el trote tanto en superficie plana como la que tiene inclinación de 5°.

Assessment of the quadriceps femoris muscle in women after injury induced by maximal eccentric isokinetic exercise with low angular speed.

UNLABELLED: The objectives of this study were to propose a model for exercise- induced muscle injury by way of a maximal eccentric isokinetic exercise at low angular speed, and assess the time course of functional recovery of the injured quadriceps femoris muscle from the maximal voluntary contraction (MVC) torque and electrical activity (root mean square - RMS and median frequency - MDF). The effectiveness of the proposed eccentric exercise in inducing injury was assessed from the activity of creatine kinase (CK). In addition, the presence of edema of the quadriceps femoris muscle was assessed by a visual inspection of the intensity of the magnetic resonance imaging (MRI) signal. These measurements were carried out before and after the exercise. Ten healthy women (21.9 ± 1.5) took part in this study. The injury was induced by 4 series of 15 maximal eccentric isokinetic contractions at 5°/s. The MVC torque reduced up to the 4(th) day after the exercise (p < 0.05). The RMS of the vastus medialis oblique (VMO) and the rectus femoris (RF) muscles decreased on the 2(nd) (VMO and RF; p < 0.05) and 3(rd) (RF; p < 0.05) days after. The MDF of the VMO increased immediately after (p < 0.05), whilst the MDF of the RF and VL decreased immediately after (RF; p < 0.05), on the 1(st) (RF and VL; p < 0.05) and on the 2(nd) (VL; p < 0.05) days after. The CK activity increased on the 2(nd) day after (p < 0.05). An increase in the intensity of the MRI signal was observed on the 2(nd) and 7(th) days after. IN CONCLUSION: 1- the eccentric exercise with low angular speed was effective in inducing injury, 2- the quadriceps femoris already started its functional recovery, as shown by the MVC torque and electrical activity, in the first week after the exercise, despite the presence of an increase in the intensity of the MRI signal. Key pointsThe low angular speed eccentric exercise was effec-tive in inducing injury of the quadriceps femoris muscle, and could be used as a muscle injury induc-ing model in future studies;The quadriceps femoris muscle injured by eccentric exercise started its functional recovery in the first week after low angular speed eccentric exercise.

The effect of hip abduction on the EMG activity of vastus medialis obliquus, vastus lateralis longus and vastus lateralis obliquus in healthy subjects.

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: The purposes of this paper were to investigate (d) whether vastus medialis obliquus (VMO), vastus lateralis longus (VLL) and vastus lateralis obliquus (VLO) EMG activity can be influenced by hip abduction performed by healthy subjects. BACKGROUND: Some clinicians contraindicate hip abduction for patellofemoral patients (with) based on the premise that hip abduction could facilitate the VLL muscle activation leading to a VLL and VMO imbalance METHODS AND MEASURES: Twenty-one clinically healthy subjects were involved in the study, 10 women and 11 men (aged X = 23.3 +/- 2.9). The EMG signals were collected using a computerized EMG VIKING II, with 8 channels and three pairs of surface electrodes. EMG activity was obtained from MVIC knee extension at 90 degrees of flexion in a seated position and MVIC hip abduction at 0 degrees and 30 degrees with patients in side-lying position with the knee in full extension. The data were normalized in the MVIC knee extension at 50 degrees of flexion in a seated position, and were submitted to ANOVA test with subsequent application of the Bonferroni multiple comparisons analysis test. The level of significance was defined as p < or = 0.05. RESULTS: The VLO muscle demonstrated a similar pattern to the VMO muscle showing higher EMG activity in MVIC knee extension at 90 degrees of flexion compared with MVIC hip abduction at 0 degrees and 30 degrees of abduction for male (p < 0.0007) and MVIC hip abduction at 0 degrees of abduction for female subjects (p < 0.02196). There were no statistically significant differences in the VLL EMG activity among the three sets of exercises tested. CONCLUSION: The results showed that no selective EMG activation was observed when comparison was made between the VMO, VLL and VLO muscles while performing MVIC hip abduction at 0 degrees and 30 degrees of abduction and MVIC knee extension at 90 degrees of flexion in both male and female subjects. Our findings demonstrate that hip abduction do not facilitated VLL and VLO activity in relation to the VMO, however, this study included only healthy subjects performing maximum voluntary isometric contraction contractions, therefore much remains to be discovered by future research.

Anamnestic index severity and signs and symptoms of TMD.

The aim of this study was to determine the frequency and to characterize the symptoms and clinical signs of temporomandibular disorders (TMD) related to each severity category of Fonseca's anamnestic index in a sample of Brazilian young adults (mean age 21.61+/-1.91 years, 87% females and 13% males), by the application of an anamnestic index proposed by Fonseca (1992) and by clinical examination considering mandibular range of motion and tenderness to palpation of stomatognathic system structures. A significant number of participants were classified with mild TMD (43.2%) and moderate TMD (34.8%). Pain frequency during mastication, temporomandibular joint (TMJ) pain, and TMJ sounds were shown to be good predictors of TMD severity. Neck pain, headache, difficulty during mouth opening and lateral deviation, and tenderness to palpation of masticatory sites and during protrusion accompanied the TMD severity but failed to demonstrate differences between moderate and severe groups, showing a poor ability to determine TMD severity progression. This study suggests that not only the frequency of signs and symptoms of TMD should be determined, but also symptom severity and its relationship to the presence of clinical signs in order to discriminate patients with real treatment needs in nonpatient samples.

Avaliação eletromiográfica dos músculos estabilizadores da patela durante exercício isométrico de agachamento em indivíduos com síndrome da dor femoropatelar / Electromyographic activity evaluation of the patella muscles during squat isometric exercise in individuals with patellofemoral pain syndrome

O objetivo deste trabalho foi comparar a atividade elétrica dos músculos vasto medial oblíquo (VMO), vasto lateral longo (VLL) e vasto lateral oblíquo (VLO) durante os exercícios isométricos de agachamento wall slide a 45º (WS 45º) e 60º (WS 60º) de flexão do joelho. Foram avaliadas 15 mulheres clinicamente saudáveis e 15 mulheres com síndrome da dor femoropatelar (SDFP). Os registros eletromiográficos foram obtidos por eletrodos ativos simples conectados a um eletromiógrafo durante a contração isométrica voluntária máxima (CIVM) do WS 45º e WS 60º. Os dados foram analisados pela média dos valores do root mean square (RMS) do sinal eletromiográfico, normalizado pela média do RMS obtido no agachamento a 75º de flexão do joelho. A análise estatística empregada foi o teste ANOVA two way (p < 0,05) e teste de Duncan post hoc (p < 0,05). Os resultados revelaram que o exercício WS 60º apresentou maior atividade elétrica nos músculos VMO, VLL e VLO quando comparado com o WS 45º, para os grupos controle e SDFP. Durante o WS 60º, para o grupo controle, não foram observadas diferenças na atividade dos músculos VMO, VLO e VLL, sugerindo um equilíbrio na atividade elétrica destes músculos, enquanto que no WS 45º o músculo VLL apresentou maior ativação quando comparado com os músculos VMO e VLO. Para o grupo SDFP, esse equilíbrio entre as porções medial e lateral do músculo quadríceps foi observado em ambos os exercícios. Esses dados sugerem que WS 60º, para o grupo controle, pode ser mais efetivo para programas de fortalecimento muscular. Contudo, para o grupo com SDFP, ambos os exercícios podem ser indicados durante o programa de reabilitação. Além disso, a ausência de diferenças na atividade eletromiográfica dos músculos VMO, VLO e VLL entre os grupos, neste estudo, sugere que o desequilíbrio muscular pode não ser um fator predisponente da SDFP.

Analysis on the activation of the VMO and VLL muscles during semisquat exercises with and without hip adduction in individuals with patellofemoral pain syndrome.

OBJECTIVE: The purpose of this study was to investigate the effect of hip adduction on the activity of the Vastus Medialis Obliquus (VMO) and Vastus Lateralis Longus (VLL) muscles during semisquat exercises. METHODS: Twenty female subjects, divided into two groups comprising healthy and patellofemoral pain syndrome (PFPS) subjects (ten volunteers for each group), performed three double-leg semisquat exercise trials with maximum hip adduction isometric contraction (DLSS-HA) and three double-leg semisquat exercise trials without hip adduction (DLSS). The normalized electromyographic muscle data were analysed using Repeated Measure ANOVA (p

A influência da altura do step no exercício de subida posterior: estudo eletromiográfico em indivíduos sadios e portadores da síndrome da dor femoropatelar / Step height influence on backward step-up exercise: an electromyographic study in healthy individuals and in those with patellofemoral pain syndrome

O objetivo deste estudo foi avaliar a influência da altura de um step na atividade elétrica dos músculos vasto medial oblíquo (VMO), vasto lateral longo (VLL) e vasto lateral oblíquo (VLO) no exercício de subida posterior. Participaram do estudo 27 indivíduos do sexo feminino, sendo 15 sadios (21,13 ± 2,17 anos) e 12 portadores da Síndrome da Dor Femoropatelar-SDFP (21,08 ± 2,31 anos). A atividade elétrica foi captada por eletrodos de superfície. Os indivíduos subiram o step em duas alturas diferentes (45° e 75° de flexão do joelho) no sentido posterior. A integral do sinal elétrico normalizado pela média das repetições foi utilizada para o estudo da relação de ativação VMO:VLO e VMO:VLL. A ANOVA two-way e o post hoc de Duncan (p < 0,05) mostraram que no grupo SDFP, os valores da relação VMO:VLO e VMO:VLL foram maiores no ângulo de 45° do que a 75°. No grupo Controle, a relação VMO:VLO foi maior a 45° que a 75° enquanto que a relação VMO:VLL foi maior no ângulo de 75°. Os resultados deste estudo sugerem que o exercício de subida posterior no step a 45° está indicado no tratamento da SDFP, pois ativou mais seletivamente o músculo VMO.

Contribution to the anatomical study of the oblique portionof the Vasculite Laterais muscle

Thirty-two human thighs were dissected to determine the anatomical organization of the two portions of the vastuslateralis muscle, and their relationships with associated structures the lateral retinaculum and iliotibial tract. In all ofthe cases, the vastus lateralis muscle consisted of a long, proximal portion, (the vastus lateralis longus - VLL), and anoblique, distal portion (the vastus lateralis obliquus - VLO). The oblique portion (VLO) originated from the asperaline of the femur and from the lateral intermuscular septum. The tendon of the VLO ran below and laterally to the longportion (VLL), which it subsequently joined on the superolateral border of the patella. The VLO also interdigitatedwith the lateral retinaculum and iliotibial tract. The VLL showed an extensive aponeurosis in its proximal two thirds.The gross morphology of the VL muscle agreed whith previous descriptions for this muscle and suggested that theVLO could play an important role in patella stabilization. This muscle could therefore be of clinical importance in thetreatment of disorders involving the patellofemoral joint.Key words: Anatomy, lower limb, muscle, quadriceps femoris

Effect of local cryotherapy and elevation on dextran-induced edema in the hind paw of rats

The purpose of this study was to analyse the effect of local cryotherapy associated with elevation in the course of dextran induced-edema in the hind paw of rats. The animals were divided into five groups as it follows: control group (n=10); elevation of paw during 30 minutes (n=10); elevation of paw during one hour (n=10); cryotherapy and elevation for 30 minutes (n=10) and cryotherapy and elevation for 1 hour (n=10). The increase in the thickness of the paw was expressed in percentage, considering the values obtained before and 30 minutes, 1, 2, 4 and 6 hours after the application of dextran. The data were analysed by test of Student, at the 5(per cent) level of significance. The results of this research showed that cryotherapy associated with elevation reduced dextran induced edema in the hind paw of rats more effectively when applied for one hour rather than 30 minutes. This suggests that cryotherapy and paw elevation have influence in the course of edema. Paw elevation was probably responsable for decreasing capillary hydrostatic pressure and increasing lymphatic function. Cryotherapy produced vasoconstriction, reduced metabolism and also reduced liberation and action of histamine in the endothelial junctions.