Anatomical predictors of maximum isometric and concentric knee extensor moment

Abstract

The most important anatomical determinants of in vivo joint moment magnitude have yet to be defined. Relationships between maximal knee extensor moment and quadriceps muscle volume, anatomical (ACSA) and physiological (PCSA) cross-sectional area, muscle architecture and moment arm (MA) were compared. Nineteen untrained men and women performed maximal isokinetic knee extensions under isometric conditions (90 degrees joint angle) and at 30 degrees and 300 degrees s(-1). Magnetic resonance and ultrasound imaging techniques were used to measure vastus lateralis PCSA and fascicle length (FL), quadriceps ACSA, volume and patellar tendon MA. Muscle volume was the best predictor of extensor moment measured isometrically (R(2) = 0.60) and at 30 degrees s(-1)(R (2) = 0.74). PCSA x FL was the best predictor of moment at 300 degrees s(-1) (R(2) = 0.59). MA was not an important predictor. ACSA was the second best predictor at all three speeds and could be recommended as an ideal measure given its relative ease of measurement.

Contribution of Neuromuscular Factors to Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

“…The biggest regulator of these interlimb deficits appeared to be deficits in isometric and isokinetic peak torque production, which are functional mechanical properties of muscle that are highly related to changes in muscle architecture. 25,27,29,32,33 Specifically, we found large inter- limb deficits with strong ESs and narrow CIs during isometric testing; this muscle-mechanic alteration is related to changes in muscle volume and physiological CSA 25,26 and can also be regulated by a change in pennation angle. 27,34 Additionally, interlimb differences in quadriceps strength were identified during isokinetic testing, 27-29 a functional mechanical change in muscle that is highly related to muscle phenotyping.…”

“…24 Alterations in isometric and isokinetic relationships lend insight into the underlying maladaptations in quadriceps muscle morphology that lead to decreased quadriceps strength after ACLR. For instance, a decrease in the physiological cross-sectional area (CSA; physiological CSA ¼ [muscle volume 3 cos h (pennation angle) / fiber length]) of the quadriceps would directly influence the torque-length (isometric) curve by reducing the overall peak torque, 25,26 and a change to the torque-velocity curve, derived from isokinetic testing, could result from a shift in the fiber types present within the muscle.…”

Confiabilidade de medidas de arquitetura muscular do tríceps sural por ultrassonografia de imagem. DOI: 10.5007/1980-0037.2012v14n2p212

“…Em pesquisa de Kawakami et al 21 são reportados valores médios similares de AP do GM com ICC de 0,98, entretanto, com percentuais mais altos de CV (14,28%), provavelmente pela grande heterogeneidade da amostra em relação a idade e gênero (homens e mulheres de 3 a 94 anos. Além disso, existem diferenças inerentes à condição de ativação da musculatura estudada (repouso e contração submáxima e máxima) como pode ser visto nos estudos de Blazevich et al 2 , Martin et al…”

“…Medidas de parâmetros de arquitetura muscular têm sido cada vez mais utilizadas em estudos das propriedades contráteis do músculo tais como área de secção transversa anatômica e fisiológica, volume muscular, comprimento da fibra (CF), espessura muscular e ângulo de penação (AP) [1][2][3] . A arquitetura muscular sofre alterações devido a estímulos externos, condições patológicas ou estado fisiológico do indivíduo 1,4 .…”

Associations of maximal voluntary isometric hip extension torque with muscle size of hamstring and gluteus maximus and intra-abdominal pressure

“…Hip extension strength has been considered as one of the most important factors contributing to daily living activity and athletic performance (Athanasios et al 2002;Lord et al 1996;Yamauchi and Ishii 2007). It is generally considered that the muscle size (e.g., anatomical cross-sectional area (ACSA) and thickness) of the hamstring and/or gluteus maximus (GM) is mainly responsible for the maximal voluntary hip extension torque, similar to the well-known relationship between joint torque and muscle size in other muscle groups (Blazevich et al 2009;Fukunaga et al 2001). To the best of our knowledge, however, available information on the substantial relationship between hip extension torque and size of these muscles is limited to the report…”