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Association of Gastrocnemius Muscle Stiffness With Passive Ankle Joint Stiffness and Sex-Related Difference in the Joint Stiffness

Kentaro Chino*1 and Hideyuki Takahashi*1

*

1Japan Institute of Sports Sciences
Journal of Applied Biomechanics

Vol. 34: , Issue 3, : Pages 169-174
(Issue publication date: June 2018)

https://doi.org/10.1123/jab.2017-0121
Passive ankle joint stiffness is affected by all structures located within and over the joint, and is greater in men than in women. Localized muscle stiffness can be assessed by ultrasound shear wave elastography, and muscle architecture such as fascicle length and pennation angle can be measured by B-mode ultrasonography. Thus, the authors assessed localized muscle stiffness of the medial gastrocnemius (MG) with consideration of individual variability in the muscle architecture, and examined the association of the muscle stiffness with passive ankle joint stiffness and the sex-related difference in the joint stiffness. Localized muscle stiffness of the MG in 16 men and 17 women was assessed at 10° and 20° plantar flexion, neutral anatomical position, and 10° and 20° dorsiflexion. Fascicle length and pennation angle of the MG were measured at these joint positions. Passive ankle joint stiffness was determined by the ankle joint angle–torque relationship. Localized MG muscle stiffness was not significantly correlated with passive ankle joint stiffness, and did not show significant sex-related difference, even when considering the muscle architecture. This finding suggests that muscle stiffness of the MG would not be a prominent factor in determining passive ankle joint stiffness and the sex-related difference in the joint stiffness.

 

Good night, it is also important to know the force that is applied to the ankle to stimulate the gastrocnemius muscle in its torque-angle tests. Here is a document that helps calculate this torque.

A section of the paper presents a way to calculate the torque generated by the ankle joint. This method is based on the measurement of the reactions generated in a plane parallel to the sole of the foot. The place of the application of the 4 reaction forces, the center of the plate and the place of application of the force generated by the ankle is known. It was used 4 piezoelectric sensors in the 4 vertices of the plate. The movement of the cake was stimulated by the electrodes on the test subject's leg. This tells us that the person did not move the foot voluntarily, but pretended the effects of electrical objects on the ankle.
They used rigid strips to immobilize the leg and knee of the user, so that the only force that is applied is the ankle and do not bend the knee. When they digitized the reaction, the minimum value they could register was 2.7 N / bit, due to the resolution of their analog-digital converter (12 bits) and the resolution of their sensor (0.9mV / N).
They fulfilled the objective of verifying that the movements generated by the ankle in a frontal plane are of less intensity than those generated in the other planes, that is, in the direction of the plantar or dorsal flexion. However, this torque is relevant to the stability of the person.