Acute effects of static stretching on muscle–tendon mechanics of quadriceps and plantar flexor muscles
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This study aimed to determine the acute effects of static stretching on stiffness indexes of two muscle groups with a contrasting difference in muscle–tendon proportion.
Eleven active males were tested on an isokinetic dynamometer during four sessions randomly presented. Two sessions were dedicated to quadriceps and the two others to triceps surae muscles. Before and immediately after the stretching procedure (5 × 30 s), gastrocnemius medialis and rectus femoris fascicle length and myotendinous junction elongation were determined using ultrasonography. Passive and maximal voluntary torques were measured. Fascicle and myotendinous junction stiffness indexes were calculated.
After stretching, maximal voluntary torque similarly decreased for both muscle groups. Passive torque significantly decreased on triceps surae and remained unchanged on quadriceps muscles. Fascicle length increased similarly for both muscles. However, myotendinous junction elongation remained unchanged for gastrocnemius medialis and increased significantly for rectus femoris muscle. Fascicle stiffness index significantly decreased on medial gastrocnemius and remained unchanged on rectus femoris muscle. In contrast, myotendinous junction stiffness index similarly decreased on both muscles.
Depending on the muscle considered, the present results revealed different acute stretching effects. This muscle dependency appeared to affect primarily fascicle stiffness index rather than the myotendinous junction.
KeywordsFascicle Myotendinous junction Stiffness Gastrocnemius medialis Rectus femoris
Analysis of variances
Fascicle length at rest
Maximal Voluntary contraction
Partial eta square
Range of motion
Passive torque changes
Researchers involved in collecting data in this study have no financial or personal interest in the outcome of results.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
- Cè E, Longo S, Rampichini S et al (2015) Stretch-induced changes in tension generation process and stiffness are not accompanied by alterations in muscle architecture of the middle and distal portions of the two gastrocnemii. J Electromyogr Kinesiol 25:469–478. doi: 10.1016/j.jelekin.2015.03.001 CrossRefPubMedGoogle Scholar
- Cohen J (2013) Statistical power analysis for the behavioral sciences. Routledge Academic, New YorkGoogle Scholar