Effect of sex and fatigue on quiet standing and dynamic balance and lower extremity muscle stiffness

Abstract

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Acute Effects of Different Intensities during Bench Press Exercise on the Mechanical Properties of Triceps Brachii Long Head

“…Although many studies have analyzed muscle electromyography [13][14][15], metabolic and endocrine changes [16][17][18] as indicators of fatigue arising during and after resistance exercise, there is less research investigating the impact of resistance exercise on the mechanical properties of muscle [19][20][21]. Non-invasive methods, such as tensiomyography and myotonometry, assess muscles' contractile and mechanical properties, respectively.…”

“…Non-invasive methods, such as tensiomyography and myotonometry, assess muscles' contractile and mechanical properties, respectively. However, it seems that tensiomyography has been used more often [19,20,[22][23][24][25] than myotonometry [21,26], despite the fact that the device for myotonometry measurement (the Myoton) is more practical, being faster due to no electrical stimulation being needed, as is the case with tensiomyography (after electrode placement, the protocol consists of increasing intensity, i.e., five steps of 10 mA with a 10 s interval in between to avoid potentiation and fatigue [27]), and the device is much smaller, making it easier to transport. Moreover, the Myoton device has been validated for measurement of muscle tone and stiffness in healthy participants with "good" to "excellent" (intra-and inter-rater) reliability [28] and shows a high level of agreement compared with measurements from shear-wave ultrasound elastography [29,30].…”

“…Acute changes in muscle mechanical properties (measured by Myoton) due to exercise were indicated as fatigue or potentiation (acute muscle function improvement due to previous muscle activity) [21,26,27]. Studies in which the Myoton device was used show mainly increases in muscle stiffness due to the fatiguing protocols (Wang et al, 2016(Wang et al, , 2017Klich et al, 2019;.…”

“…Studies in which the Myoton device was used show mainly increases in muscle stiffness due to the fatiguing protocols (Wang et al, 2016(Wang et al, , 2017Klich et al, 2019;. For instance, Klich et al [32] reported an acute increase in vastus lateralis stiffness after all-out 200 m and 4000 m track cycling, with a higher increase after 200 m. An exception is the study by Hill et al [21], which indicated an acute decrease in vastus lateralis and gastrocnemius lateralis muscle stiffness induced by a fatiguing protocol consisting of five sets of 20 drop jumps. Furthermore, a study by Po żarowszczyk et al [26] found an acute increase in Achilles' tendon stiffness and elasticity after back squats with increasing external load (from 60 to 100% one-repetition maximum (1RM), with 10% steps).…”

The effects of eccentric exercise on passive hamstring muscle stiffness: Comparison of shear-wave elastography and passive knee torque outcomes

“… 4 Muscle stiffness is also affected by various exercise, 1 , 5 muscle damage 6 and menstrual cycle. 7 Therefore, there are several areas of application for assessment of muscle stiffness, with several different methods being used in the literature, including myotonometry, 8 , 9 passive joint torque measurements, 10–13 and quantification of shear modulus through ultrasound-based shear-wave elastography. 12-14 However, it is not entirely clear if these methods can be used interchangeably.…”