Biomechanics and Energetics with Rodger Kram, PhD

My guest today was, Rodger Kram PhD, a leading scientist in the field of biomechanics with research foci in: (1) Partitioning of the rate of metabolic energy expenditure into its biomechanical constituents; AND (2) The influences of internal and external forces on the way humans and other animals walk and run. His group developed the force sensing treadmill and they have generated novel insight into many of the factors important to ultra runners, especially the biomechanics, energetics, and neural control of walking and running. He joined us from the University of Colorado at Boulder.



Dr. Kram’s work has spanned many years and several topics of interest to ultra runners. Here are the papers I asked him about; click on the PubMed ID (PMID) links to be taken to the abstract page for that research article. If you’re not familiar with PubMed, you can watch my short tutorial.


  • The role of elastic energy storage and recovery in downhill and uphill running. PMID: 22675189

Shoe mass

  • Altered Running Economy Directly Translates to Altered Distance-Running Performance. PMID: 27327023

Shoe cushion

  • A test of the metabolic cost of cushioning hypothesis during unshod and shod running. PMID: 24441213

Walking vs running

  • Applying the cost of generating force hypothesis to uphill running. PMID: 25083347

  • Energetics of vertical kilometer foot races; is steeper cheaper? PMID: 26607247

  • Mechanical work for step-to-step transitions is a major determinant of the metabolic cost of human walking. PMID: 12409498

  • Muscle contributions to propulsion and braking during walking and running: insight from external force perturbations. PMID: 25096545

Gluteal use

  • Modulation of leg muscle function in response to altered demand for body support and forward propulsion during walking. PMID: 19249784

  • Activity and functions of the human gluteal muscles in walking, running, sprinting, and climbing. PMID: 24218079

Arm swing

  • The metabolic cost of human running: is swinging the arms worth it? PMID: 25031455

  • The energetic cost of maintaining lateral balance during human running. PMID: 22052870

  • The effects of step width and arm swing on energetic cost and lateral balance during running. PMID: 21316058