Exercise has less influence on contractile properties of short muscle length

A recent publication from Emeric Chalchat suggests that the joint angle has an effect on muscle alterations after exercise-induced muscle damage. Usono’s Probefix Dynamic was used for this study.

Electrical activity in muscles
This study was designed to investigate whether the electrical activity in muscles was differently affected over time by the joint angle after an exercise-induced muscle damage. Additionally, the researchers wanted to identify the underlying factors within the muscle–tendon unit.

For this study 15 young males performed a 45-min downhill walking. Measurements were assessed before, within 1 hour, and in the hours (4 h, 24 h, 48 h, 72 h, and 168 h) after the exercise. During the investigation Usono’s probe fixation device, Probefix Dynamic, was placed over the skin without applying excessive pressure to the muscles. Probefix Dynamic enables 360 degree adjustment.

Chalchat et al. (2023), have measured the mechanical properties of the muscle–tendon unit at two muscles: Vastus lateralis and Rectus femoris. Ultrafast ultrasound imaging (Supersonic Imagine) was used to determine the optimal transducer position to localize the muscle fascicles. Halfway down the right limb, it was important to attach the transducer and mark the position on the skin, to ensure the same positioning along the experiment.

The results suggest that the joint angle has an effect on muscle alterations
Their results suggest that the joint angle has an effect on muscle alterations after exercise-induced muscle damage. The results show that muscle stiffness was more increased at long muscle length, compared to short muscle length after the exercise.

In this ultrasound research, the ProbeFix Dynamic contributed to new insights in the mechanical properties of Vastus lateralis and Rectus femoris.

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