The Claim
Knee extension to 180 degrees significantly reduces soleus muscle electrical activity compared to knee flexion at 90 and 135 degrees, indicating that maintaining a 90-degree knee flexion angle optimizes soleus recruitment during plantar flexion, likely mediated by the muscle's monoarticular anatomy and length-tension relationship.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Bending your knee to 90 degrees makes your soleus calf muscle work better than keeping it completely straight. This happens because of how the muscle is built and how its length changes with different knee angles. So, if you want to activate this muscle most effectively during movements like calf raises, keeping a slight bend in your knee is best.
See the scientific wording
Soleus muscle electrical activity decreases significantly when the knee is fully extended at 180 degrees compared to flexed positions at 90 and 135 degrees. This reduction in activation suggests that maintaining knee flexion at 90 degrees optimizes soleus recruitment during plantar flexion movements, likely due to the muscle's monoarticular structure and length-tension relationship.
What the research says
1 studyStudy: Selective Recruitment of the Triceps Surae Muscles With Changes in Knee Angle
Bending your knee to 90 degrees makes the soleus muscle work harder during calf raises than keeping it straight, because of how the muscle is built and stretches.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.