R Kram

Summary

Affiliation: University of California
Country: USA

Publications

  1. ncbi Effect of reduced gravity on the preferred walk-run transition speed
    R Kram
    Human Biodynamics Department, University of California, Berkeley 94720 4480, USA
    J Exp Biol 200:821-6. 1997
  2. ncbi Force treadmill for measuring vertical and horizontal ground reaction forces
    R Kram
    Department of Integrative Biology, University of California, Berkeley, California 94720 3140, USA
    J Appl Physiol 85:764-9. 1998
  3. ncbi Exploring dynamic similarity in human running using simulated reduced gravity
    J M Donelan
    Integrative Biology Department, University of California, Berkeley, CA 94720 3140, USA
    J Exp Biol 203:2405-15. 2000
  4. ncbi Energetics and biomechanics of locomotion by red kangaroos (Macropus rufus)
    R Kram
    Department of Integrative Biology, University of California, Berkeley 94720 3140, USA
    Comp Biochem Physiol B Biochem Mol Biol 120:41-9. 1998
  5. ncbi Metabolic cost of generating horizontal forces during human running
    Y H Chang
    Locomotion Laboratory, Department of Integrative Biology, University of California, Berkeley, California 94720 3140, USA
    J Appl Physiol 86:1657-62. 1999
  6. ncbi Muscular force or work: what determines the metabolic energy cost of running?
    R Kram
    Integrative Biology Department, University of California, Berkeley 94720 3140, USA
    Exerc Sport Sci Rev 28:138-43. 2000
  7. ncbi How animals move: an integrative view
    M H Dickinson
    Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
    Science 288:100-6. 2000
  8. ncbi Applied horizontal force increases impact loading in reduced-gravity running
    Y H Chang
    Locomotion Laboratory, Department of Integrative Biology, University of California, Berkeley, CA 94720 3140, USA
    J Biomech 34:679-85. 2001
  9. ncbi Mechanical and metabolic determinants of the preferred step width in human walking
    J M Donelan
    Department of Integrative Biology, University of California, Berkeley, CA 94720 3140, USA
    Proc Biol Sci 268:1985-92. 2001
  10. ncbi Mechanical work for step-to-step transitions is a major determinant of the metabolic cost of human walking
    J Maxwell Donelan
    Department of Integrative Biology, University of California, Berkeley, CA 94720-3140, USA
    J Exp Biol 205:3717-27. 2002

Collaborators

Detail Information

Publications29

  1. ncbi Effect of reduced gravity on the preferred walk-run transition speed
    R Kram
    Human Biodynamics Department, University of California, Berkeley 94720 4480, USA
    J Exp Biol 200:821-6. 1997
    ..This supports the hypothesis that the walk-run transition is triggered by the dynamics of an inverted-pendulum system...
  2. ncbi Force treadmill for measuring vertical and horizontal ground reaction forces
    R Kram
    Department of Integrative Biology, University of California, Berkeley, California 94720 3140, USA
    J Appl Physiol 85:764-9. 1998
    ..This device greatly decreases the time and laboratory space required for locomotion experiments and clinical evaluations. The modular design allows for independent use of both treadmill and force platform...
  3. ncbi Exploring dynamic similarity in human running using simulated reduced gravity
    J M Donelan
    Integrative Biology Department, University of California, Berkeley, CA 94720 3140, USA
    J Exp Biol 203:2405-15. 2000
    ..This suggests that a single unifying hypothesis for the effects of size, velocity and gravity on both walking and running gaits will not be successful...
  4. ncbi Energetics and biomechanics of locomotion by red kangaroos (Macropus rufus)
    R Kram
    Department of Integrative Biology, University of California, Berkeley 94720 3140, USA
    Comp Biochem Physiol B Biochem Mol Biol 120:41-9. 1998
    ..The cost of transport (J kg-1 m-1) decreases at faster hopping speeds, yet red kangaroos prefer to use relatively slow speeds that avoid high levels of tendon stress...
  5. ncbi Metabolic cost of generating horizontal forces during human running
    Y H Chang
    Locomotion Laboratory, Department of Integrative Biology, University of California, Berkeley, California 94720 3140, USA
    J Appl Physiol 86:1657-62. 1999
    ..Our data suggest that generating horizontal propulsive forces constitutes more than one-third of the total metabolic cost of normal running...
  6. ncbi Muscular force or work: what determines the metabolic energy cost of running?
    R Kram
    Integrative Biology Department, University of California, Berkeley 94720 3140, USA
    Exerc Sport Sci Rev 28:138-43. 2000
    ..Whole animal experiments, in vivo muscle force and fascicle length recordings, and in vitro muscle shortening velocity data support the idea...
  7. ncbi How animals move: an integrative view
    M H Dickinson
    Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
    Science 288:100-6. 2000
    ..Integrative approaches reveal not only how each component within a locomotor system operates but how they function as a collective whole...
  8. ncbi Applied horizontal force increases impact loading in reduced-gravity running
    Y H Chang
    Locomotion Laboratory, Department of Integrative Biology, University of California, Berkeley, CA 94720 3140, USA
    J Biomech 34:679-85. 2001
    ..An appropriate AHF could easily augment existing partial gravity treadmill running exercise countermeasures used during spaceflight and help prevent musculoskeletal degradation...
  9. ncbi Mechanical and metabolic determinants of the preferred step width in human walking
    J M Donelan
    Department of Integrative Biology, University of California, Berkeley, CA 94720 3140, USA
    Proc Biol Sci 268:1985-92. 2001
    ..12L, which is not significantly different from foot width (0.11L) or the preferred step width (0.13L). Humans appear to prefer a step width that minimizes metabolic cost...
  10. ncbi Mechanical work for step-to-step transitions is a major determinant of the metabolic cost of human walking
    J Maxwell Donelan
    Department of Integrative Biology, University of California, Berkeley, CA 94720-3140, USA
    J Exp Biol 205:3717-27. 2002
    ..95), and linearly with mechanical work rate. Mechanical work for step-to-step transitions, rather than pendular motion itself, appears to be a major determinant of the metabolic cost of walking...
  11. ncbi Simultaneous positive and negative external mechanical work in human walking
    J Maxwell Donelan
    Locomotion Laboratory, Department of Integrative Biology, 3060 Valley Life Sciences Building, University of California, Berkeley, CA 94720 3140, USA
    J Biomech 35:117-24. 2002
    ..At all speeds, the trailing leg performs greater than 97% of the double support positive work while the leading leg performs greater than 94% of the double support negative work...
  12. ncbi Changing the demand on specific muscle groups affects the walk-run transition speed
    Jamie L Bartlett
    Locomotion Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO 80309, USA
    J Exp Biol 211:1281-8. 2008
    ..However, the lack of a summation effect with multiple external devices, suggests that another underlying factor ultimately determines the preferred walk-run transition speed...
  13. ncbi Effects of independently altering body weight and body mass on the metabolic cost of running
    Lennart P J Teunissen
    Department of Integrative Physiology, University of Colorado, Boulder, CO 80309, USA
    J Exp Biol 210:4418-27. 2007
    ..However, 74% is probably an overestimate of the metabolic demand of body weight to support itself because in reduced gravity conditions decrements in horizontal impulse accompanied decrements in vertical impulse...
  14. ncbi Effects of obesity on the biomechanics of walking at different speeds
    Raymond C Browning
    Locomotion Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO, USA
    Med Sci Sports Exerc 39:1632-41. 2007
    ....
  15. ncbi The effects of adding mass to the legs on the energetics and biomechanics of walking
    Raymond C Browning
    Department of Integrative Physiology, University of Colorado, Boulder, CO 80262, USA
    Med Sci Sports Exerc 39:515-25. 2007
    ....
  16. ncbi Limitations to maximum running speed on flat curves
    Young Hui Chang
    Comparative Neuromechanics Laboratory, School of Applied Physiology, Georgia Institute of Technology, Atlanta, GA 30332 0356, USA
    J Exp Biol 210:971-82. 2007
    ..The ability of quadrupeds to redistribute function across multiple stance legs and decouple these multiple constraints may provide a distinct advantage for turning performance...
  17. ncbi Mechanical energy fluctuations during hill walking: the effects of slope on inverted pendulum exchange
    Jinger S Gottschall
    Department of Integrative Physiology, University of Colorado, Boulder, CO 80309, USA
    J Exp Biol 209:4895-900. 2006
    ..e. mechanical energy exchange was less effective. Mechanical energy exchange occurred during downhill, level and uphill walking, but it was most effective during downhill walking...
  18. ncbi The locomotor kinematics of Asian and African elephants: changes with speed and size
    John R Hutchinson
    Structure and Motion Laboratory, Department of Veterinary Basic Sciences, The Royal Veterinary College, University of London, Hatfield, Hertfordshire, AL9 7TA, UK
    J Exp Biol 209:3812-27. 2006
    ....
  19. ncbi Effects of obesity and sex on the energetic cost and preferred speed of walking
    Raymond C Browning
    Dept of Integrative Physiology, 354 UCB, Univ of Colorado, Boulder, CO 80309 0354, USA
    J Appl Physiol 100:390-8. 2006
    ..43). Detailed biomechanical studies of walking are needed to investigate whether obese individuals adopt novel energy saving mechanisms during walking...
  20. ncbi Energy cost and muscular activity required for leg swing during walking
    Jinger S Gottschall
    Department of Integrative Physiology, University of Colorado, Boulder, USA
    J Appl Physiol 99:23-30. 2005
    ..Thus our data indicate that approximately 10% of the net metabolic cost of walking is required to initiate and propagate leg swing. Additionally, the hip flexor muscles contribute to the initiation and propagation leg swing...
  21. ncbi Energetic cost and preferred speed of walking in obese vs. normal weight women
    Raymond C Browning
    Department of Integrative Physiology, 354 UCB, University of Colorado, Boulder, CO 80309, USA
    Obes Res 13:891-9. 2005
    ....
  22. ncbi Giant Galapagos tortoises walk without inverted pendulum mechanical-energy exchange
    Peter A Zani
    Department of Integrative Physiology, University of Colorado, Boulder, CO 80309 0354, USA
    J Exp Biol 208:1489-94. 2005
    ..Nevertheless, contrary to biomechanical convention, poor inverted-pendulum mechanics during walking do not necessarily correspond to high mechanical work and may not result in a high metabolic cost...
  23. ncbi Ground reaction forces during downhill and uphill running
    Jinger S Gottschall
    Department of Integrative Physiology, University of Colorado, Campus Box 354, Boulder CO 80309 0354, USA
    J Biomech 38:445-52. 2005
    ..Our parallel force data provide insight into past energetic studies, which show that the metabolic cost increases during downhill running at steep angles...
  24. ncbi Biomechanical and energetic determinants of the walk-trot transition in horses
    Timothy M Griffin
    Department of Integrative Biology, University of California, Berkeley, CA 94720 3140, USA
    J Exp Biol 207:4215-23. 2004
    ..These results support the hypotheses that the walk-trot transition is triggered by inverted-pendulum dynamics and occurs at the speed that maximizes metabolic economy...
  25. ncbi Mechanical and metabolic requirements for active lateral stabilization in human walking
    J M J Maxwell Donelan
    Department of Physiology, University of Alberta, Edmonton, AB T6G 2H7, Canada
    J Biomech 37:827-35. 2004
    ..body lateral motion is partially stabilized via medio-lateral foot placement, (c). active stabilization exacts a modest metabolic cost, and (d). humans avoid narrow step widths because they are less stable...
  26. ncbi Metabolic cost of generating muscular force in human walking: insights from load-carrying and speed experiments
    Timothy M Griffin
    Department of Integrative Biology, University of California, Berkley, California 94720, USA
    J Appl Physiol 95:172-83. 2003
    ..11 +/- 0.03 (SD) J/cm3]. These data indicate that, regardless of the work muscles do, the metabolic cost of walking can be largely explained by the cost of generating muscular force during the stance phase...
  27. ncbi Biomechanics: Are fast-moving elephants really running?
    John R Hutchinson
    Biomechanical Engineering Division, Stanford University, Stanford, California 94305 4038, USA
    Nature 422:493-4. 2003
  28. ncbi Energy cost and muscular activity required for propulsion during walking
    Jinger S Gottschall
    Department of Kinesiology and Applied Physiology, University of Colorado, Boulder, Colorado 80309, USA
    J Appl Physiol 94:1766-72. 2003
    ..Our data indicate that generating horizontal propulsive forces constitutes nearly half of the metabolic cost of normal walking. Additionally, it appears that the MG plays an important role in forward propulsion, whereas the Sol does not...
  29. ncbi Running with horizontal pulling forces: the benefits of towing
    Alena M Grabowski
    Department of Integrative Physiology, University of Colorado, 354 UCB, Boulder, CO 80309 0354, USA
    Eur J Appl Physiol 104:473-9. 2008
    ..Ultimately, the race performance time and body mass of each runner determine the optimal towing force...