Biomechanical Analysis of Rou,ing
Tetsuo Fukunaga, Keizo Yamamoto, Akifumi N{atsuo
Department of Sports Sciences, College of Arts andSciences, University of Tokyo

Abstract

The rowing performance is affected b! the mechanical energy output exerted by the oarsman. By using the rowing tank, in which the water is flowed by the motor driven pump, suchbiomechanical parameters as the angular displacements of oar, the forces applied to an oar andto a stretcher were measured by means of specially designed apparatus. The results were as
follows ;1). Skilled oarsmen indicated a larger area covered by F"/@n curve (i.e. relation between theforce applied to the oarlock pin (F") and the angular displacement of an oar (OH)), and theoar blade proceeding in the water almost parallel to the horizontal plane. In the unskilledoarsmen on the other hand, smaller area covered F"/frE curve and deeply inserted bladein the water were observed.
2). Skilled oarsmen indicated that the displacement of the seat (D.) ilcreased with the increasing angle of oar in horizontal plane (@n), while the unskilled should no increase in D. in
the phase of the second half of stroke, suggesting that the kinetic energy due to the
movement of the body of the oarsman on the sliding seat is transferred more to the oar
in skilled oarsman thart in unskilled man.
3). Gross mechanical efficiency increased linearly with the increasing force applied to the pin(F") at low intensities. At higher intensities the gross efficiency indicated a range between
15% and 20%, which were almost same values as those in bicycle exercise.

The performance in a boat race is influenced by the magnitude of mechanical energy
applied to water b!'oar blade, and in turn the mechanical energy output is affected by suchparameters as the movemelts of an oar and a seat, and the forces applied to an oar and astretcher. By measuring these parameters, it may be considered to evaluate the rowing techniques and energy capacity of athietes. However, it takes much time and necessitates labours

10

and scientific techniques to neas.re them during actual rowing in the boat course- In thisrespect use of a rowing tank, in which water is circulated motor driven pump, makes eachmeasurements comparatively easicr. Although ir is unavoidable to cause a feeling of the difference, in " touch " between rowing irl the tank and actual rowing, it is convenient to substitue
rowing tank for the actual course. ln this study, apparatuses were devised to record electricallythe force applied to an oarlock pin and a stretcher, the angular displacement of an oar, andthe displacement of a seat during stroking. using these apparatuses the mechanical energ)'
and o{ygen uptake during rowing were rneasured and also rowing techniques were evaluatedfrorr a biomechanical point of view.

1. Apparatus
Fig. 1 shows a specially designed oarlock pin, a stretcher and a seat. The inside detailsof an oarlock pirl were shown in Fig. 2. The angular displacement of oar in the horizontal orvertical direction is observed by each potentiometer. The forces working on the front, back,Figure 1. Schematic illustration of speciatly designed oarlock
pin(l), foot stletcher(2), and seat (S).

for horizonlol ongle
Figure 2. Ioside details of an oarlock pin. The Iorces applied tothc piu were measured by four strain gauge transduceE
which were set up around the main axis. The angulardisplacement of oar were measured in horizontal andvertical directiofl by each potensiometer.

11

and right and Ieft of the pin were measured by four strain gauge traosducers which were set
up around the main axis. The force applied to the stretcher was measured b-v means of pressure transducers set on the ball of foot, and these pressure forces were recorded separately on
the right and left side foot. The movement of the seat was recorded by means of linear potentiometer which was attached to the back side of the seat.

2. Movements and pressurr of oar, seat and stretcher during rowing in the tank
In ngures 3 and 4 the angular displacement of the oar, the forces obtained from the oarlock
pin and stretcher, and the displacement of the seat were indicated. The flow rate of the waterin the rowing tank was 3.2ms'. The rowing frequency was about 30 strokes per min. withmaximum effort. ln Fig. 4 the symbol SW represents the signals whether an oar blade wasin or out of the water. 6H represents the changes in the angle of an oar in the horizontal
plane and 8v in the vertical plane. Zero degree in €rrr shows that the position of oar is per-

CRUTCH
θ″

LL・

＼
↓

θ′

″ お

「
υ

]]『

Figure 4, Typical recording during maximal rowing in tank.

ｕ

ａ

ｄ

"

「
v/↑
/へ

ｎ
ｇ

ｍ

"aFF―

/1F

Ｎ

〜

ヽ

︑ ｎ
︑
︑
ｏ

ん 藤
︐ ｉ
ｃ
″ ｔ
ｗ
ａ

ｈ

／ 一
Figure゛12pendicular to the water florv. Zero in (rv curve also shows an oar being horizontal. Fr represents the force applied to the pin in the direction parallel to the water flow, which is the pro-pelling force applied to the boat. Irr represents the force applied to the pin working in theperpendicular direction to the water 0ow, which is the force pressed the boat to the lateralside. F",, represents the force applied to the outside stretcher which is set at the far side fromthe pin, while F", represents the iorce obtained from the inside stretcher located at the nearside to the pin. D" shows the displacement of the seat, in which zero means the foremost
position of the seat.

From these recordings, the rowing movement of subject NIW was described as follows; atthe moment of a blade being put in to the water, the angle of the oar in horizontal plane was
30 degrees, while in the vertical plane that was about 8 degrees. At this moment the outside
stretcher indicated maximum value of about 40kg, and the seat began to move backward which
was called " stroke phase ". The force applied to the stretcher began to increase in ,,forward
phase " or " recovery phase". When the angle of the oar in the horizontal plane (6s) was
about 90 degrees, the forces of Fr and F". indicated near maximum values. At this moment.
on the other hand, F"r and the force of pin in the lateral side, were about zero. When theseat was stopped at the backward-most position, inside stretcher force (F",) reached the valueof zero and the force of oar (F") began to decrease. At the moment of the blade coming out
of water, the angle of oar in the horircntal direction (@u) &'as about 30 degrees aod that in thevertical plane (ar) about 8 degrees, and the forces applied to both inside and outside stretchers
had already reached zero.

3. Analysis of rowing p&tt€rn of skilled and unskilled oarsmen
Figure 5 indicates the relation between F" and OH in a stroke. Upper two curves wereol)tained from the most skilled oarsmen (SH, HOR) who competed in the 1984 Los Angeles
StiIodＦ⁚Ｌ ｒ⁚﹂ Ｆ

1500

1000
０
０
５
０

⁚﹂

︵Ｚ︶

３

ｒｌ ＬΓ

０

⁚
∞ ∞ ︒

０﹂

unsklled

﹂

＼

￨
0

●
30

‐
30

0H
̀doO,and unskilled oarsmeD.
!'igure 5. Relation between F'" and 6H for skilled

:500
1000

2

500

ＯＬ

unsk‖ lod
ＦＩＩトーＩＬ

20

40

60

20

Ds

(cm)

Figuie 6. Relation between F" and D,.

Olympics. l,ower curves were for the second class oarsmen (FUK, AWA). These force-angle
curves showed signilicant differences between skilled and unskilled athletes. In the skitled peak
point of F" were observed before tclrr reached zero, which mean ntaximum force was exerted in
the first half of the stroke, while in the unskilled exerted the peak force in the second half ofthe stroke.
The area surrounded by force-angle curves implies mechanical work exerted by an oar.
The skilled clearly indicated larger force-angle curye area than the unskilled. It was consideredthat higher mechanical work exerted b1' an oar was the fundamental lactor to get good performance in a boat race. Changes in F" were shown \yith displacement of seat (DJ in Fig. 6.
Zero in abscissa (D.) represents the position in which the seat was drawn forward-most up.
The peaks of F" curve of the skilled men were observed while the seat was moving backward.
In the unskilled athletes the peaks of F" were observed at maximum backward-most positionof the seat. On the assumption that the movement of the seat expresses almost the same asthat of the center of gravity of the bod-\-, the kinetic energy derived from the movement ofan oarsman could be transfered to the mechanical energy of the oar. The magnitude of mechanical energy transfered from the movement of the body to the oar may be considered to
be expressed by the area surrounded by F.-D. curve. Larger area of F"-D" curve in the skilledathletes that they could transfered more rnechanical energy from the moveme[t of the bodyto the oar than that could in the unskilled.
ln rowing, the oar rotates on the axis of an oarlock pirl in both horizontal and verticalplane. The relation of the angular displacement of the oar betlveen both in horizontal (BH) andvertical (6v) planes are indicated in Fig. 7. As shown in this 6gure, higher 6v in the unskilledthan that in the skilled athletes implies that the oar blade in the skilled were more deeply in'３８ ︶Ｆ ｌ ｌ ｌ ｌ ト ー ｌ ｌ ｌ Ｌ
０
０
５

‐30

0

OH

(doO)

。30

‐30

＞①
Figure 7. Relation between OH and 6..

■ ｏ︶
∽∩

o30

0H

‑30

(d.g)

Figure 8. Relation between Ds and Orr.

0

・ 30

15

serted into the water than in the unskilled and the oar blade in the skilled also proceeded in
the water almost parallel to the horizontal plane.

Fig. 8 shows the relationship between arH and D-. ln skilled athletes D" increased withincreasing 6s, while in the unskilled no increase in D" was observed in the phase of the second
half of a stroke. It may be considered that the increment of 6s with increasing D" shows thatthe mechanical energy is smoothl]' transfered fl'oni the body to the oar.

4. Mechanical efficiency in tank rowing
The ratio of energy expended b] the muscle contraction to the mechanical work is defined
as a mechanical effciency. Many different values for a mechanical efficiency in rowing wereobserved in previous studies (14-26+1o.1-t.s *1

The mechanical efiiciencf is influenced by the various factors such as the equation to be
used in the calculation, the mode of the muscular exercise, the method for measuring mechan-ical work and energy consumption. and the technical skilled to be prformed in the muscularexercises. Gaesser and Brooks(') attempted to compare rhe different methods lor calculationof the mechanical efficiency such as gross, net, work and delta ef6ciency, and they reported
the highest value of delta emcienc!'. Th-vs. et al.(,r) and Cavagna and Kaneko(,) reported thatthe emciency of exercise which contained eccentric contraction of muscle was higher than thatof the concentric contraction, which implied higher mechanical efficiency in higher sped running or jumping with high frequencl'. As for the effect of skills or techniques of exercise on
the efficiency, Cunningham et al.(i) reponed that the similar mechanical efficiencies were foundfor both experienced and inexperienced oarsmen, rvhereas Asami et a1.1,) suggested that higher
mechanical efficiency night be obtained from more skillful rowing performance.
To measure the mechanical emciency of rowing in the present study, the oarsmen sat ina nonnal rowing position, being allowed to adjust the seat, the slide assembly and the foot toconlorm to his wishes. Before the measurement the subject performed 5 strokes of rowing
with maximum effort so as to estimate the maximum value of force in a stroke exerted to theoarlock pin (F.-",). After 10 minutes of resting on the ro$.ing seat, the subjects were requested
to row with the stepwise incremental loading method, i. e. rorvilg intensity was increased up
to 100% F"-", at 10% per evert 2 minutes. The determination of the intensity was carriedout by the instruction of a coxwain !,!'ho monitored recordings of the force applied to the pin(F") on the oscillograph. Oxygen uptake and heart rate were measured during resting andexercise conditions at every 30 seconds by means oi an automatic oxygen analyzer (ERGO
OXYSCREEN, JEAGER, WDST GERMANY) and telemeter (SANEI 2E31A), respectively.

1'he mechanical work (\v,,) exerted b1- a[ oarsman rvas calculated from the following
equation;*"=o", T*, rsin ry,,,-rsin @,:where E is the mean force applied to the pin, a and b are the lever arms of the force applied
to the oar by the handgrip and that the force applied to the blade, respectively, and €)H is the16angle between the oar and the line perpendicular to the water llow. The mechanical power(*.) is calculated from

W":W.xf
where f is stroke frequency in a minute. The mechanical work is obtained every stroke dur'ing rowing.
The mechanical eficiencies are determined by the following equations which were definedby Gaesser and Brooks(').
Gross efficiency tCE):fx f OO

Ner efficiency rNE,=fl;.,100

Work efficiency tWEl=g$; x rOO
Delta efficiencl {OEl=ff xrOO

where E is gross energy output including resting metabolism, e; resting energy, E'; energy
output in loaded rowing, E,;energy output in unloaded rowing (W.:0), dW"; increment inwork performed above previous work rate, and dE; increment of energy consumption abovethat of a previous work rate.
The relationship between oxygen uptake iV"r) and mechanical work in various rowing intensities, under the condition of anaerobic threshold, was shown in Fig. 9. At the uDloaded rowing (W.:0) V", was 1.12t0.11 l.min 1(meants.d.). At low intensity of rowing, betow about＾Ｅ Ｅ ヽ こ
８一
＞

o

5
Wo

to

t5

20

(Jrrot/,rrrn,

Figure 9. Relationship between V., anrl W". lsoeflicienct' lines,
the inclination of which is the ratio between values inabscissas and ordiates are based on energl- equivalent of
20.93 JIL 0,.

ｏ一● ゛∽０﹂０︵■・︶ゝｏＣ●一

一
一

600

穐

5

(
'

Figure 10. Changes in gross emciency with mean force applied to pin (F").

EFFICIENCY

10

20

(96)

30

40

N.,

Drrro

'__--- Blcrcllng (G......)

Figure 11, Comparison of mechanica, eftrciency between present study and previous teports.
7000 J.min 'of W., V", increased curvilinearly with the increase of W". At higher intensities,

however. the reclilinear relation was observed between V., and W", and the gross emciency
indicated a range between 15% and 20%.

The relation between F" and GE was shown in Fig. 10. GE increased linearly with increasing F. in the low intensities, while above about 500 N of R the efficiency indicated almost
constant value of L7 .5%.
In the present study, no changes in the range of On \vere observed, i.e. independent of
W.. so that the increment of W" was calrsed by the increase in F" and stroke freque[cy. This
result was in good agreement with that of DiPrampero et al.(i), in which the displacement ofhandgrip was practically constant at all rowing frequencies, while the average pull and thework done per stroke increased with the frequency. The increment of the emciency $rith increasing F" in the present study agreed with some previous studies, which showed that in bicycle pedalling exercise the emciency increased with increase in work rate and that the eficiency in rowing increased with the increasing stroke frequency(').
Some different values of the mechanical emciency during rowing exercise were reported
follows;
20-26% (Henderson and Haggard('0)), 18-23% (DiPrampero et al.(')), 18.111.9%(Asamias
et al.(')). The comparison of the efficiency between the present study and the previous reports
were shown in Fig. 11. Differences if these reported values could be explained in termsof the

18measurements in the works done, the exercise protocols and the calculation of the efficiency.
DiPrampero et al.(') and Asami et al.(') measured the force applied to the oar by using strain
gauge mounted on the oar, and calculated the mechanical work from the product of the force

on the oar and displacement of the handgrip on the oar. These experimental methods were
almost same as that of the present study.
The gross efficiency in the present sludy (17.5%) was much the same as that in basintank ro!,v'ing (10-20%\a) and lower than that in actual rowing (78-23n1t't. DiPrampero et al.(r)reported that lower values of the emciency in basin rowing than in actual rowing was causedby higher frequency of rowing stroke at a given work load in basin, because higher stroke
frequency costs greater energy per minute due to more transverse component (energy loss) of
the force applied to the pin. The stroke frequency in the plesent study (15 20f min') was
lower than that in actual rowing (20-25f.min') of DiPrampero et al.(?). This result suggeststhat the difference in the efficiencies between actual and tank rowing was not solely due to thedifference in stroke frequency.
To obtain an accurate measurement of the emciency it is necessary to measure the mechanical work exerted by the muscle and also the energy consumed only for that work. In
rowing, not only arm but leg and trunk muscles are activated, resulting more recruited muscle
mass than other type of exercise like bicycle pedalling. The net emciency has been the mostfrequently used method in calculating the mechanical efficiency. ln this calculation, however,
the energy cost of the moving leg, arm and trunk was not considered in the estimation ofwork done by the exercising subject. ln the rowing exercise this energy cost could not ignored
because of about 1l.min ' of V., being consumed in unloaded rowing. In consideration of thisunloaded energy cost, the work or delta emciency is theoretically acceptable. Whipp andWasserman(r3) relnrted that 10% higher values of the work efliciency were considerably higher
than gross and net emciency in the bicycle exercise. As shown in Fig. 11, although delta efficiency in the present study indicated a little lower than that in bicycle exercise, it was considered that mechanical efficiencies in rowing indicated almost same values as those in bicycle
exercise.

Relerencea(1)

Asami, T., N. Adachi and K. Yamamoto. Biomechanical analysis of rowing performa[ces. A.
Morecki et al. (eds), Biomechanics VII-R, pp.,142-446, University Park Press, Baltimore, 1981.
Asmussen, E. Aerobic recovery afte! anaerobiosis in rest and work. Acta Physiol. Scand, l1:
197-210,1946.

Cavagna, G.A. and M. Kaneko. Mechanical work and emciency in level walking and luDEing. J.
11)

Physiol. 268: 467-{81, 1977.
Christensen. E.H. an(l P. tlogberg. The efiiciency of anaerobical wo!k. Arbeitsphysiologie 14: 249250. 1950.

('￨

Cun[ingham, D.,\., P.l]. Goode and J.B. Critz. Clardiorespifttory lesponse of exercise on a rowing
and bicycle ergometer. Med. Sci. Spotts 7', 37-13, 1975,
Diem, K. Documenta Geigy Scientific Tables (6th ed.). Ardsley, NY: Geigy Pharmaceuticals, p.
628. t962.

19(7) DiPrampero, P.E., c. Cortili, F. Celentano and P. Cerretelli. phl.'siological aspects of rowing. J.
Appl. Physrol. 3l : 8i3 857, 1971.

(8) Gaesser, G.A. and G.A. Brooks. N{uscular effici€ncy during steady rate exercise: effects oJ speed
and work rate. J. Appl. Physiol. 38: 1132 1139, 1975.
(9) Hagerman, F.C., M.C. Conners. J.A. Gault, G.R. Hagerman and W.J.polinski. Energy expenditureduring simulated rowiDg. J. Appl. Ph,vsiol. 45: 87 93, 1978.

(10) Hende6on, Y. and H.W. llaggard. The maximum of human power anct its Juel. Amer. J. phrsiot.
72 | 264 242, 1925.
(ll) Thys, H., T. Faraggiana and R. Margaria. Utilization of muscle elasticjty in exercise. J. AppI.
Physiol. 32: 491-494, 1972.

(12) Wasserman, K., B.J. Whipp, S.N. Ko-r-al and W,L. Beaver. Anaerobic threshold and respiratory
gas exchange during exercise. J. Appl. Physiol. 35: 236-243, 1979.

(13) Whjpp, B.J. and K. W-asserman. El6cienc1.of muscular work. J. Appl. physiol.26: 644-648. 1969.