Delayed onset of electromyographic activity of the vastus medialis relative to the vastus lateralis may be related to physical activity levels in females with patellofemoral pain

Abstract

The aims of this study were to examine group differences in muscle activation onset of the vastus medialis (VM) in relation to the vastus lateralis (VL) and pain level during stair ascent in females with patellofemoral pain (PFP) who maintain high and moderate levels of physical activity; to determine the association between physical activity level and muscle activation onset. Forty-three females with PFP and thirty-eight pain-free females were recruited and divided into four groups based on their level of physical activity: females with PFP (n=26) and pain-free females (n=26) who practiced a moderate level of physical activity and females with PFP (n=17) and pain-free females (n=12) who practiced an intense amount of physical activity. Participants were asked to ascend a seven-step staircase and the VM and VL activation onset was determined. Females with PFP who practiced high level of physical activity demonstrated delayed onset of VM (4.06ms) compared to healthy females (-14.4ms). Conversely, females with PFP who practiced moderate level of physical activity did not present VM delay (-2.48ms) in comparison to healthy females (-9.89ms). Furthermore, physical activity significantly correlated to the muscle activation onset difference (p=0.005; R=0.60). These findings may explain why controversial results regarding VM and VL muscle activation onset have been found.

Influence of body mass index on patellofemoral pain

“…A conservative treatment approach for PFP patients takes into account the biomechanical dysfunction characterized by increased adduction and medial rotation of the hip in closed kinetic chain and delayed activation of the vastus medial in open kinetic chain and involves strengthening the muscles Influence of body mass index on patellofemoral pain of the hip and quadriceps response to ameliorate the pain and improve function in this condition [3,26,27,28]. Mechanical overload and stress on the cartilage of the patellofemoral joint may occur due to a decrease in the contact area generated by these biomechanical changes, which are independent of BMI [29].…”

“…Para verificación de las variables de dolor al reposo y al esfuerzo, se utilizó la Escala Numérica de Dolor, y para la variable función, se utilizó la escala Kujala de dolor existente en la rodilla. Las participantes se dividieron en dos grupos, de acuerdo con el IMC, siguiendo los criterios de la Organización Mundial de la Salud (OMS): grupo 1 compuesto por mujeres con IMC normal (18-24,9 kg/m²) con 36 pacientes, y el grupo 2 compuesto por mujeres con sobrepeso (25)(26)(27)(28)(29)9 kg/m²) con 18 pacientes. Se realizó la comparación de los promedios de dolor al reposo y al esfuerzo y de la escala entre los grupos, por medio de la prueba t de Student para las muestras independientes y de la prueba de Mann-Whitney, considerando significancia estadística p < 0,05.…”

Comparação do nível de dor femoropatelar, atividade física e qualidade de vida entre adolescentes do sexo feminino e masculino

“…Em estudo de Briani et al [4], indivíduos com DFP que apresentavam maiores níveis de atividade física reportaram maior dor no joelho em comparação com indivíduos que praticavam menores níveis de atividade física. Além disso, aquele estudo reportou que indivíduos que praticavam altos níveis de atividade física apresentaram atraso no início da ativação do músculo vasto medial em relação ao vasto lateral durante subida e descida de escada quando comparados a indivíduos com DFP que praticavam níveis moderados de atividade física.…”

“…Além disso, é uma condição que, na maioria das vezes, está presente na população fisicamente ativa e é responsável por impactar não somente a participação em esportes, mas também a qualidade de vida e as atividades de vida diária [3,4]. Esse distúrbio musculoesquelético é comum entre adolescentes, acometendo cerca de 6 a 7% dessa população [5].…”

Differences in muscle contraction onset as determined by ultrasound and electromyography

“…As such, EMG‐detected contraction onset refers the initiation of electrical activation. The sEMG is usually used for superficial muscles, while fwEMG is highly selective and usually reserved for smaller, deeper musculature . However, fwEMG is an invasive technique and may be contraindicated for some populations, while the interpretation of neural control from sEMG is highly constrained .…”