Απόσπασμα από το ROWING BIOMECHANICS Νοέμβριος 2010

8/8/2019 Απόσπασμα από το ROWING BIOMECHANICS Νοέμβριος 2010

http://slidepdf.com/reader/full/-rowing-biomechanics-2010 1/3

awo TO ROWING BIOIVIECHANICS

2010

NEA

Ta anoT£A£CT|jaTa T O U "rrpdacpaTou riayKdaLJiou

C J T O Kapanipo T H C , N£ac, Zr|Aav6iac, 6dxvouv ncoc, oi

A A £ y . BpETaviaq laxuponoincrav T P J V 0£OT| T O U C , : n£puai K£p6iaav 6

LjadAAia a£ OAupniaKd aycoviajjaTa, £va and auTd xpuad aAAd

c p £ T O c , K£p6iaav 9 (jadAAia £ K T C D V onoicov T O 4 rnav xpuaa. Oi

A y y A o i dvai aiyoupa anocpaaia|j£voi va «andaouv» T O U Q

avTindAouc, Touq QTOUC; SIKOUQ T O U C ; OAuijniaKOUc; TOU 2012.

H oiKo6£andTr(c; TOU npcoTaGAnijaTOC,, NEQ Zr|Aav6ia K£p6ia£ 7

| j£TdAAia C T£ OAuLjniaKa ayooviaijaTa, 3 £< T C O V onoicov xpuad. 'Eva

PnMa napandvco 6r|Aa6n and n£puai O T O V K£p6ioav «(jdvo» 5

(jadAAia.

Oi ADarpaXoi ^£ATicoaav Tfjv KOTdTa^ n T O U C ; and T H V 7^ n£puaivn

9£an QTHV 3n cpeioq. AmAaaiaaav T O | j£TdAAia Touq a£ auyKpior)

|j£ TOV 2009 |j£ 4 | j£TdAAia Tcbpa, av <ai K a v £v a xpuad, E K T O C ; and

T O Xpuad LjrraAAio Thomas Keller nou anovqjn0r|K£ C T T O V (j£va

James Tomkins.

Oi T£p|javoi £n£oav and T P J V 2n Qiar\v 4n |j£ 3 pdvo [ j£TdAAiacpaoc; £vavTi T C O V 5 nepuai. AUTO TO 6 ua d p £ Q T O yeyovoq

YAuKd0r iK£ Aiyo and THV Karaiaricrri TO U xpuo'ou (JETaAAiou

OKTOKCono T C O V AvSpcbv.

Oi 'EXAr|V£g un d T H V aocpn Ka9o6nyno"n TO U T^idviP>£ATicoaav K O T O noAu Tiqv K a T d T a ^ n T O U C ; acpou and T F J V n£puaivr]

9n 6£an KaT£KTr)C7av cperot; Tf|v 5n . KaT£KTncrav 3 | j£TdAAia, av K OI

Kavtva xpuad cperoc;.

Oi A|j£piKavoi cp£Toq (jnriKav Q T I Q 6 KaAuT£p£Q x^P^Q TOU KOQIJOU

|j£ n£piaaoT£pouc; |j£v ndvTOuc, and T O U C ; 'EAAr|V£c;, aAAd |j£ 2 (jdvo| j£TdAAia, 6r)Aa6n £ va AiydT£po and n£puai.



v o l u m e 1 0 N O 1 1 6 Rowing S/o/r7ec/7a/7/cs Newsletter November 2010

News

The results of the recent W orld cham pion ships in

Karapiro, New Zealand (see Ap pendix 1 below) show

that the leaders, Great Britain have made their position

stronger: last year they won six medals in Olympic

events , one of them gold , but this year they w on ninemedals , four of them were gold . The Brits def in i te ly

intended to smash their opposi t ion dur ing their home

Olympics-2012.

The hosts of the c h a m p i o n s h i p s , N ew Zealand w on

seven medals in Oly mp ic events, three of them were

gold. This is one step up compare to the last year,

when th e «k iw i s» got "only" five meda ls .

The Aussies increased their rank from seventh place

last year to th i rd . They doubled th e amoun t of medals

compare to 2009 with four medals now, though no

gold among them, except gold Thomas Keller medal

awarded to the great James Tomkins .

T he Germans have fa l len from second place down to

fourth, with only three medals after five last year. This

bit ter fact was sweetened by the most prestigious gold

medal in M8+.

The Greeks un der wise leade rship of Gianni Post ig-

l ione increased the i r r ank f rom th e ni nth place last year

to the t i l th now . They got three medals, one more com-

pared to 2 U U y , tnougli no gold this year.

The Amer icans conc lude the six best countr ies of

the World with more poin tsm an Greeks , but with only

two medals, which is one less than last year.

Facts. Did you know that...

. . . u s ing EM G (electro-myography) is the best

method to study muscle activity in any human move-

m e n t ? A pilot s tudy was conducted on a mob ile rowin g

ergometer with the purpose to evaluate the sequence of

muscles act ivat ion d ur in g the stroke cycle. Three most

powerful muscle groups were chosen: quads (Rectus

femoris), hamstr ings (Biceps femoris and Semimem-

bmnosus) and gluts (Glutens medius). Delsys Myo-

monitor® wireless EM G system w as used and eight

electrodes were placed on r ight and left muscles of theabove g roups . Six samples were taken on a sculler of

an in te rnat ional level at the stroke rates 20, 24, 28, 32,

36 and 40 str /min. F ig . l below shows the EMG of

three major mu scle groups at 36str/min in conjunct ion

with velocities of the body segments.Activity of the quads began significant ly earlier than

the catch, because the row er needs to d ecelerate the relativ e

movements of the masses at the end of recovery an d thenstart their acceleration at the be g inn ing of the drive. It is

interesting that activation of the quads decreased down to

zero after th e legs achieved their maxim al velocity (mom ent

1 on Fig. l ) and the rower started using his t runk . Ham -strings an d gluts rapidly increase it s activation at this m o-

ment. This could be a specific feature of this rower as he

has a hump in the legs velocity curve at the same time,which may indicate a lack of coo rdina tion of activities of

the quads and hamstrings (RBN 2008/07). The pattern of

th e quads activation has three peaks during th e drive and the

second peak (moment 2) corresponds with the second peak

of legs velocity. The third peak of the quads activation oc-

curred at the finish of the dr ive - beginning of recovery hasthe highest electrical activity. This ca n be expla ined by a

hi p flexion action (rectus femoris is connected to the pelvis)and pulling the stretcher through, which requires straight

legs.

EMG Q ua ds(Rectus femoris)

EMG Hams

(Biceps feme

EMG Glut

(Glutens

2 Body Segm ents\/olr»r»it\ (fn/c -

Catch

T he peak of t runk veloci ty (moment 3) coincides

with the peak o f E M G o f hams t r ings and glu ts , which

produces the highest power during the drive through

rotation in hip joints.

It is noticeable that EM G curves are qui te asym-

metrical: left hamstr ing and g lu t produce higher e lec-

trical impulse at the middle of the drive, but rightquads do more at the finish of the drive . This cou ld be

related to a specific injury of the athlete.

Conc lud ing , EMG method shows a good corre-

spondence with mechanical variables of rowing and

m ay be used fo r evaluation of rower's technical ef-

fectiveness. The method requ i res further deve lopmen t

of the analys is rout ine based on various pat terns of

rowing technique both on-ergo and on-water.

Acknowledgment for the support of th is s tudy is

given to the English Ins t i tu te of Sport and Bri t i sh

Rowing .Contact U s:

©2010: Dr. Valery Kleshnev, www. biorow. com



Appendix 1Ranking of the countries based on results in 14 Olympic events on the World Cham pionship 2010 in Karapiro

New Zealand and its comparison with results of 2009 World championship in Poznan, Poland.

^

Rank

2010

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

Country

GBR

NZL

AUS

GER

GRE

USA

CAN

ITA

FRA

CZE

CHN

SWE

CRO

BLR

UKR

ROU

POL

NED

NOR

RUS

POR

SLO

SRB

Number of places 2010

1st

4

3

1

1

1

1

1

1

1

And

4

1

2

1

1

1

2

1

1

3rd

1

3

2

1

2

1

1

1

1

1

4th

2

3

2

1

1

2

1

2

5th

2

1

1

1

3

1

2

2

1

6th

2

3

1

2

1

1

1

1

1

1

7th

2

1

3

1

1

1

2

1

1

Medals

2010

9

7

4

3

3

2

2

2

2

1

1

1

1

1

1

1

1

0

0

0

0

0

0

Points

2010

75

54

38

39

16

25

22

20

16

16

15

9

8

6

6

6

5

10

8

5

2

2

2

Rank

2009

1

3

7

2

9

5

13

12

6

8

23

21

14

16

11

4

10

24

22

15

25

Medals

2009

6

5

2

5

2

3

1

1

2

2

0

0

0

11

2

4

2

0

0

0

10

Points2009

50

39

23

55

14

27

13

16

27

18

3

0

4

10

8

12

32

12

2

4

0

9

3

Red co lour means improvement ,

blue colour — decrease of results.

Απόσπασμα από το ROWING BIOMECHANICS Νοέμβριος 2010

Documents

Transcript of Απόσπασμα από το ROWING BIOMECHANICS Νοέμβριος 2010