The Claim
In individuals with bilateral plantarflexor weakness, lower passive muscle stiffness is associated with higher optimal ankle-foot orthosis (AFO) stiffness for energy cost reduction, with optimal AFO stiffness increasing from 3.7 Nm/degree at normal passive stiffness to 4.5 Nm/degree at 20% of normal passive stiffness.
What the research says
Not yet evaluated
We are still looking at what the research says.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
In people with weakened calf muscles, the stiffness of their ankle-foot orthosis that minimizes energy use during walking increases as their natural muscle stiffness decreases.
See the scientific wording
In individuals with bilateral plantarflexor weakness, lower passive muscle stiffness is associated with higher optimal AFO stiffness for energy cost reduction, increasing from 3.7 Nm/degree at normal passive stiffness to 4.5 Nm/degree at 20% of normal passive stiffness.
When the calf muscles and tendons are too loose, the ankle collapses inward too far during walking, making it hard to push off the ground and keep the knee straight. A stiffer brace stops the ankle from collapsing too much, stores energy as the foot lifts up, and releases it to help push the foot down and extend the knee, which saves energy.
What the research says
1 studyWhen calf muscles are weak and floppy, people walk better with a stiffer ankle brace — and this study shows that the floppier the muscles, the stiffer the brace should be to save energy while walking.
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.