simulation of the airborne phase of the grand jetÉ in ballet
DESCRIPTION
SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET. D. Gordon E. Robertson, PhD, FCSB Pamela Galler, BSc Lisa Stanley, BSc Biomechanics Laboratory, School of Human Kinetics, University of Ottawa, Ottawa, CANADA. Introduction. Grand jet é is one of the strongest jumps in ballet - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/1.jpg)
SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET
D. Gordon E. Robertson, PhD, FCSB
Pamela Galler, BSc
Lisa Stanley, BSc
Biomechanics Laboratory,
School of Human Kinetics,
University of Ottawa, Ottawa, CANADA
![Page 2: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/2.jpg)
Introduction
• Grand jeté is one of the strongest jumps in ballet
• It is characterized by a leap that travels horizontally
• Laws (2002) proposed that it is possible for the upper body to appear to translate in flight while the centre of gravity follows its parabolic path
![Page 3: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/3.jpg)
Grand Jeté
![Page 4: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/4.jpg)
Methods
• Two experienced ballet dancers/instructors
• Performed several grand jetés in sequence with a step in between jumps
• Some trials were done landing on a force platform
• Video taped at 60 fps
• 10-segment model of body (i.e., hands and feet ignored)
• Planar motion analysis
![Page 5: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/5.jpg)
Methods
• Takeoff velocity determined from data preceding and after takeoff
• Initial estimate of total body angular momentum taken from average of flight phase momenta
• Joint displacements, initial position at takeoff, initial velocity and angular momentum were then used to iteratively obtain changes in trunk angle during flight (Lemaire & Robertson 1990)
• Total body angular momentum was adjusted by comparing simulated motion with actual motion
![Page 6: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/6.jpg)
Methods
tjjj
Ip
Ip
rvmrM
pMpp
iii
iitotaliii
N
ii
N
iitotal
)()1()(
/
)(
)]([
111
111
1/1
211
![Page 7: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/7.jpg)
Methods
• Once a successful simulation was achieved:
1. Hip joint displacements were modified to elevate lower extremities to produce full “split” in the air prior to reaching peak height
2. Shoulder joint displacements were then modified to raise the upper extremities until a “flat” trajectory of the head and shoulders was achieved
![Page 8: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/8.jpg)
Results
• Neither dancer had a flat trajectory of the upper body during their jumps
• Raising the legs to achieve a “split” configuration in the air was insufficient to achieve a flat trajectory
• Raising the arms past the horizontal was necessary to achieve the linear translation illusion with both dancers
![Page 9: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/9.jpg)
Arms High, Legs Horizontal
![Page 10: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/10.jpg)
Initial Jump
![Page 11: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/11.jpg)
Jump after Legs Raised to Horizontal
![Page 12: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/12.jpg)
Jump with Legs and Arms Raised
![Page 13: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/13.jpg)
Jump Height versus Shoulder Rise
Subject: LS PG
Actual jump height
25 cm 21 cm
Actual rise of shoulders
21 cm 19 cm
With legs raised 14 cm 13 cm
With legs and arms
0 cm 0 cm
![Page 14: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/14.jpg)
Discussion
• The illusion of “floating” through the air or linear translating while airborne could be achieved but required that the arms elevate above horizontal
• In some dance traditions this is not a permissible motion
• The illusion could be extended further by lowering the arms and legs after the jump apex, however, this may result in a hazardous landing
![Page 15: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/15.jpg)
References
• Lemaire, E.D. & Robertson, D.G.E. (1990) Validation of a computer simulation for planar airborne human motions. Journal of Human Movement Studies, 18:213-28.
• Laws, K. (2002) Physics and the Art of Dance. New York: Oxford Press.
![Page 16: SIMULATION OF THE AIRBORNE PHASE OF THE GRAND JETÉ IN BALLET](https://reader034.vdocuments.mx/reader034/viewer/2022051401/5681427a550346895daea19c/html5/thumbnails/16.jpg)
Wow! Questions?