Characterization of passive elastic properties of the human medial gastrocnemius muscle belly using supersonic shear imaging

Reliable Protocol for Shear Wave Elastography of Lower Limb Muscles at Rest and During Passive Stretching

“…This result was expected, given the mechanical nonlinear behaviour of the muscle, and is in accordance with previous studies by Maïsetti et al (2012) and Hug et al (2013), who have found an increase of muscle shear modulus during passive stretching once the threshold of the slack length was passed. Soleus muscle is not involved in knee motion, the non-significant difference confirmed that altough the ankle joint angle was not strictly controlled, muscle stiffness varied little between positions.…”

“…Kot et al (2012) found that the size of the region of interest (ROI) and the probe pressure influenced elastography measurement. Moreover, subject position affects the measurement: an increase of the shear modulus was observed when muscle is passively stretched, both in vitro (Shinohara et al, 2010;Maïsetti et al, 2012;Koo et al, 2013) and ex vivo (Eby et al, 2013). Maïsetti et al (2012) and Hug et al (2013) determined in vivo the slack length of the muscle, corresponding to a range of motion in which the muscle does not produce any passive force and in which shear modulus was constant.…”

Evidence for intermuscle difference in slack angle in human triceps surae

“…The observed slack angle of MG (211 of plantar flexion) was similar to that obtained previously from in vivo MG Maïsetti et al, 2012). Hug et al (2013) reported that slack angle for MG was less plantarflexed position than that for the Achilles tendon.…”

“…With the gastrocnemius and tibialis anterior of fresh roaster chickens, Koo et al (2013) have reported a linear relationship between the shear modulus measured by ultrasound shear wave elastography and passive muscle force. Human experiments took advantage of this technique to detect the slack angle on the medial gastrocnemius (MG) (Maïsetti et al, 2012), biceps brachii Lacourpaille et al, 2014), and tibialis anterior (Koo et al, 2014). To the best of our knowledge, so far only Lacourpaille et al (2013) have compared the slack angles among synergistic muscles.…”

Muscle-specific acute changes in passive stiffness of human triceps surae after stretching

“…Absolute differences were 1.2 ± 0.1, 0.7 ± 0.3, and 0.8 ± 0.3 kPa for MG, LG, and Sol, respectively. Additionally, previous studies have suggested that shear modulus measured by ultrasound shear wave elastography could be considerably affected by pennation angle (Gennisson et al 2010;Maïsetti et al 2012). However, more recently we have shown that the effect of pennation angle on the measured shear modulus was negligibly small (<1.3 %) (Miyamoto et al 2015a).…”