1. Anatomy & Physiology of Human Locomotion Focus on Human Adaptation

2. Human Locomotor Diversity Humans have a range of movement possibilities

3. Human Locomotor Diversity and Potential Twa of Uganda http://www.scienceupdate.com/201 3/01/climb/ Modern Californian, Yosemite

4. www.pnas.org/content/early/2012/12/26/

5. Endurance Running Hypothesis A central human adaptation? Bramble & Lieberman proposed hypothesis – Paper in Nature, 2004 Observation: Humans can run efficiently for long distances. Hypothesis: Running is a human adaptation that was advantageous for survival. Some human anatomical and physiological features are adaptations for running. Kalahari San !Kung, men running to track a large antelope they have darted.

6. Endurance Running 2009 book ER: Ability to run long distances using aerobic metabolism Evidence? Human behavior – Elite athletes – Marathons (26.2 miles; 42.195 kilometers) – 6.5 m/sec (up to 14.5 mph; 4.1 min. miles) Tarahumara of Mexico

7. Bipedal Walking Humans excel at walking long distances Optimal walking speed (for energetic efficiency) is 1.3m/sec (~3 mph) Lieberman & Bramble – Running more efficient than walking at higher speeds (~2.3 m/sec; 11.6 min. miles; ~5 mph) Bipedal walking – Inverted pendulum Running – Mass-spring gait

8. Walking versus Running http://en.wikipedia.org/wiki/File:Spring_ mass_model.jpg Science 9 September 2005: Vol. 309 no. 5741 pp. 1725-1728

9. Evidence for their Hypothesis 1.Energetics – They argue that humans are more efficient energetically than other mammals 2.Stabilisation Anatomical features that contribute to stability during running 3.Thermoregulation Most mammals run short distances; body temperature becomes too high Humans sweat, have no fur, can dissipate heat rapidly

10. Energetics Mass-spring gait – Tendons and ligaments in lower limb store energy during support phase; release energy in propulsive phase – Achilles tendon; IT band Body proportions – Shorter forelimbs compared to other primates – Long hindlimbs; increase contact time with ground – Decreased distal limb segments as percent body mass

11. Stability Enlarged gluteus maximus – Compared to what? – What is the action of gluteus maximus? – How would it function in running? – What other locomotor activities might it be important for?

12. Human and Chimpanzee

13. Hip Abductors Trunk rotators; hip abductors – Gluteus medius and minimus Prevent the body from falling to unsupported side Related to longer femoral neck Important for walking too

14. Stability Highly Mobile Thorax that is decoupled from neck Permits counter rotation of trunk and arms Decreased facial length; nuchal ligament Fewer muscular connections between shoulders and head/neck complex – Only trapezius attaches to head

15. Other Stability/Weight-bearing related features Large vertebral bodies and discs – Absorb shock Larger surface areas in knee joints – Improved shock absorption Stable, stiff arch in foot – Better push-off Larger calcaneus; Abducted big toe; shorter toes – Better push-off from ground

16. Thermoregulation Running requires 30 to 40% more energy than walking The increased number of cross bridges and increased rate of cross bridge formation during running leads to increased production of heat Human ability to dissipate heat: – Increase # eccrine sweat glands – Reduced body hair – Cranial venous circulation (helps to cool hot arterial blood before it reaches brain)

17. Summary Is the ability to run long distances a central human adaptation? What is the evidence? Are there alternative explanations for the evidence? What do people do? How does human behavior today provide information about past human adaptations?

18. Paula Radcliffe WR 2:15 marathon !Kung women (and kids)

19. Human Locomotion Homework Due at the beginning of lecture Read the following three articles and answer the questions that follow. Bramble, D.M. and Lieberman, D.E. 2004. Endurance Running and the Evolution of Homo. Nature 432: 345-352. Chen, I. 2006. Born to Run. Discover, May 2006. Lieberman, D.E. and Bramble, D.M. 2007. The evolution of Marathon Running. Sports Med. 37: 288-290. You may also use the powerpoint: Anatomy & Physiology of Human Locomotion

20. Directions: Read the rubric that follows to get a clear idea of expectations. The paper should be typed, double spaced (or 1 and 1/2 space). Type and number the questions in the paper. Answer the questions thoroughly and thoughtfully, drawing on the articles above. Some answers will be longer than others. The entire assignment should be no less than three pages long. Note: The work should be your own. Do not copy from either published sources or from other students. I will know, and the result will be 0 points for the assignment. 1. Explain the hypothesis presented by Bramble and Lieberman regarding the human locomotor adaptation. (4 points) 2. What information do the authors draw on to support their hypothesis? Discuss specific aspects of comparative behavior, anatomy, and physiology. (8 points) 3. Do you agree or disagree with the author’s conclusions? Critically evaluate the hypothesis. Did the authors provide adequate support for their idea? What additional information might be useful? What alternative explanations might explain the characteristics they attribute to adaptations for endurance running? 4. You must provide concrete information to support your argument. If you use material outside the papers listed above, you must list the source in the bibliography and include appropriate citations in the body of the paper. (8 points)

21. RUBRIC Each question has a specific number of points assigned to it. For EACH question, the following criteria will be used to assign points: Content, Organization, Citations and Bibliography, Writing Mechanics and Format. 1. CONTENT The most important aspect of the answer is quality of the content. Are the ideas clearly stated? Are they supported with specific, relevant, accurate details and examples? Quality of ideas: Synthesis of information from different sources Evidence of understanding of complex information Vocabulary:Accurate use of anatomical & physiological terms 2. ORGANIZATION Ideas are logically ordered in sentences and paragraphs. Discussion targets the question and provides a clear argument. 3. CITATIONS AND BIBLIOGRAPHY Source of information is clear. Citations in paper are the name/year method, e.g. (Bramblett and Lieberman, 2004). There is a bibliography at the end that lists sources in alphabetical order. Format of Biblography and Citations Sources must be listed in a bibliography at the end of the paper. Use the CSE (Council of Science Editors) guide. In the bibliography, list sources alphabetically according to the author's last name. Within the paper, the author's last name is enclosed in parentheses at the end of a sentence that includes information from the source. The name and parentheses are placed before the period, as in (Bramblett and Lieberman, 2007). 4. WRITING MECHANICS AND FORMAT Sentences should be coherent. There should be no spelling or grammatical errors. Questions should be typed and numbered in the paper. Your name and page numbers should be on every page. The paper should be typed).