J. R. Franz

Reduced Achilles tendon stiffness in aging persists at matched activations and associates with higher metabolic cost of walking

This study finds older adults have reduced Achilles tendon stiffness and higher metabolic cost of walking, linking lower stiffness to increased energy expenditure.

Simulations suggest walking with reduced propulsive force would not mitigate the energetic consequences of lower tendon stiffness

The paper uses simulations to show reducing push-off force during walking does not offset increased metabolic cost from lower tendon stiffness in young adults.

Relatively Shorter Muscle Lengths Increase the Metabolic Rate of Cyclic Force Production

This study shows that increasing ankle angle shortens soleus muscle fascicles and increases metabolic energy expenditure during cyclic contractions, independent of mechanical work or force rate.

Automated Analysis of Medial Gastrocnemius Muscle-Tendon Junction Displacements During Isolated Contractions and Walking Using Deep Neural Networks

This paper evaluates deep neural networks for automated tracking of medial gastrocnemius muscle-tendon junction positions in ultrasound images during walking and contractions, achieving mean absolute errors of 1.26 mm and 2.61 mm.

Muscle Metabolic Energy Costs While Modifying Propulsive Force Generation During Walking

The paper investigates how reducing propulsive force during walking increases metabolic cost by redistributing joint power from ankle to hip muscles in young adults, supporting the hypothesis that this mechanism contributes to age-related walking inefficiency.