Viscoelastic stress relaxation in the hamstrings before and after a 10-week stretching program
Related Experiment Video
Updated: Apr 17, 2026

Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Gustavo H Peixoto1, Andre G Andrade, Hans J K Menzel
1Laboratory of Biomechanics, Center of Sports Excellence, Federal University of Minas Gerais, Avenida Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
Introduction:
We investigated the viscoelastic stress relaxation response before and after a 10-week hamstrings static stretch program.
Methods:
The maximal range of motion (ROMmax ) and maximal torque (Torquemax ) were assessed before and after a 10-week stretching program. Six 30-s static stretches at a predetermined torque were performed, and the relative change in stress relaxation was examined.
Results:
ROMmax and Torquemax increased by 53% and 82%, respectively (P < 0.001). The relative stress relaxation (RSR) decreased significantly for repetition 1 when comparing the pretest (25%) and posttest (21%) values (P = 0.003). A significant decrease was also observed for repetitions 2 and 3 (P < 0.014), with no significant difference in repetitions 4-6 (P > 0.056).
Conclusions:
Individuals who participated in a 10-week hamstrings passive-static stretch program had a reduced RSR response. A higher stretch intensity or longer duration may be necessary to achieve RSRs similar to those reported before the stretch program.
Related Concept Videos
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....
Residual Stresses in Bending
Strain and Elastic Modulus
Elastic Strain Energy for Normal Stresses
If...
Plastic Behavior
Elastic Strain Energy for Shearing Stresses

