Transcript No Slide Title

Mechanics of Rowing
D. Gordon E. Robertson, Ph.D.
Yves D. Fortin, M.Sc.
Biomechanics Laboratory,
School of Human Kinetics,
University of Ottawa, Ottawa, CANADA
Supported in part by Sport Canada and the Faculty of Health Sciences
Research Development Fund.
Purpose
The purpose of this research was to
determine the mechanical roles of the
leg moments of force during the drive
(extension) phase of the rowing stroke.
Methods
• Gjessing rowing ergometer
• elevated so Kistler force platform can
measure foot reaction forces
• 4 experienced females, 5 experienced males
• filmed at 50 fps
• force transducer at handle
• inverse dynamics to obtain ankle, knee and
hip moments and powers
Experimental setup
Pulling Force
(Strain Gauge Force Transducer)
Flywheel
Workload
Adjustment
Foot
Stretcher
Force
Platform
Biological
Amplifier
Charge
Amplifier
Bridge
Amplifier
A/D
Converter
Cine-Camera
Micro-Computer
Results
• Females power came almost
exclusively from hip extensors
• may explain why Silken Laumann
was able to compete and win
bronze medal after severe injury
to calf
Powers at the hip, knee and ankle for female rowers
1500
RFEK
RFLM
RFLN
RFMM
1000
Hip
Concentric
500
0
-500
Power
(watts)
Eccentric
1000
Knee
Concentric
500
0
Eccentric
-500
500
Ankle
Concentric
0
-500
0
Eccentric
10
20
30
40
40
50
Time (% drive)
60
70
80
90
100
Results
• males produced greatest by hip
extensors
• lesser power from knee extensors
• least power by ankle extensors
(plantar flexors)
Powers at the hip, knee and ankle for male rowers
1500
1000
Concentric
500
Hip
RFBS
RFDH
RFKH
RFNT
RFSD
0
-500
Power
(watts)
Eccentric
Knee
1000
500
Concentric
0
Eccentric
-500
500
Ankle
Concentric
0
-500
0
Eccentric
10
20
30
40
50
Time (% drive)
60
70
80
90
100
Hip angular velocity, moment and power for rowing
5
Angular
Velocity
(/s)
Trial: RMBS
Flexing
0
-5
Extending
Flexor
200
Moment
of
0
Force
(N·m)-200
Extensor
Concentric
500
Moment
Power
(watts)
0
Eccentric
-500
-1000
0
10
20
30
catch
60
40
50
Time (% drive)
70
80
90
100
Knee angular velocity, moment and power for rowing
5
Angular
Velocity
(/s)
Trial: RMBS
Extending
0
-5
Flexing
200
Extensor
Moment
of
0
Force
(N·m) -200
Flexor
Concentric
500
Moment
Power
(watts)
0
-500
-1000
Eccentric
0
10
20
30
catch
40
50
60
Time (% drive)
70
80
90
100
Ankle angular velocity, moment and power for rowing
5
Angular
Velocity
(/s)
Trial: RMBS
Dorsiflexing
0
-5
Plantar flexing
Dorsiflexor
200
Moment
of
0
Force
(N·m)-200
Plantar flexor
500
Moment
Power
(watts)
Concentric
0
-500
-1000
Eccentric
0
10
20
30
catch
40
50
60
Time (% drive)
70
80
90
100