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JournalofStrengthandConditioning Research, 2007, 21(4),1192-1196

O

2007 National Strength

Conditioning ssociation

R E L A T I O N S H I P

OFJUMPING ANDAGILITY

P E R F O R M A N C E

IN

FEMALE VOLLEYBALL ATHLETES

J A C Q U E

L.

BA R ? JES BR I A N

K.

SC H I LLI N G M I C H A EL

J.

F A L V O L A W R E N C E

W.

W E I S S

A N D R E A

K.

C R E A S Y

AND

A N D R E W

C. FRY

Department of Health and

Sport Sciences, Exercise Neuromechanics Laboratory Memphis,

TN

38152.

ABSTRACT.

Barnes, J.L.. B.K. Schilling, M.J. Falvo, L.W. Weiss,

A.K. Creasy,

and

A.C.

Fry.

Relationship of jumping

and

agility

performanceinfemale volleyball athletes.

J. StrengthCond.

Res.

21 4):1192-1196.

2007.Court sports often require more fre-

quent changesofdirection (COD)than field sports. Most court

sports require 180 turns over

a

small distance,

so

COD

in

such

sports might

he

hest evaluated with

an

agility test involving

short sprintsandsharp turns.Thepurposes ofthis study were

to(alquantify verticalandhorizontal force duringaCOD task,

(hi identify possible predictors of court-sport-specific agilityper-

formance,

and (c)

examine performance difference hetween

Na-

tional Collegiate Athletic Association Division

I,II andIIIath-

letes. Twenty-nine collegiate female volleyball players completed

a novel agility test, countermovement (CMlanddrop jump tests,

and anisometric legextensor test.Thenumber ofathleteshy

divisionwas asfollows:I n =9),IIUi 11), andIII a = 9).

The agility test consisted

of4

5-meter sprints with

3

180 turns,

including

1 on a

multiaxial force platform

so

that

the

kinetic

propertiesof the CODcouldbeidentified. One-way analysisof

variance revealed that Division I athletes had significantly

greater countermovement jump heights than Division III, and

the effect size comparisons (Cohen's

d)

showed large-magnitude

differences between Division

I and

both Divisions

II andIIIfor

jump height. No other differences inperformance variahles were

noted between divisions, although effect sizes reached moderate

valuesforsome comparisons. Regression analysis revealed that

CM displacement

was a

significant predictor

of

agility perfor-

mance, explaining approximately 34%

of the

variance. Vertical

force

was

found

to

account

for

much

of the

total force exerted

duringthecontact phaseof the CODtask, suggesting thatper-

formance in thevertical domain maylimitthe CODtask used

herein. This study indicates that individuals with greaterCM

performance also have quicker agility times

and

suggests that

training predominantly

in the

vertical domain

may

also yield

improvementsincertain typesofagility performance. Thismay

bold true even ifsuch agility performance requiresahorizontal

component.

KE YWORDK.change of direction, vertical

jump

isometricleg

ex-

tensor action

I N TR OD U C TI ON

gility has been defined many ways, including

the whole body quick/accurate movement in

response to a stimulus (1) and the abiUty to

change direction, as well as to start and stop

quickly (3, 6, 7, 12, 14, 19, 33), However, it

may be more reasonable to define agility as the ability to

change direction with a minimal loss of control and/or av-

erage speed. Agility training is commonly implemented

in strength and conditioning programs; however, limited

scientific literature is available providing specific detail

on how best to train for agility. Most research on agility

performance has been concerned with injury mechanisms

(4,

16, 20, 25) and not on mechanics of these types of

movements in regard to optimizing performance. To bet-

ter explain agility. Young and colleagues (34) suggested

a model (Figure 1) that separated agility into components

of perceptual and decision-making factors and perfor-

mance factors (cbange-of-direction speed). Yet, due to the

larger number of potential performance factors in Young's

model (34), it appears that these performance factors may

play more of a role in defining agility than the perceptual

and decision-making factors, Tberefore, identification of

tbe performance variables undergirding change of direc-

tion (COD) may enable us to better explain agility.

Because tbe limiting factor in sprinting is the vertical

force due to the acceleration of gravity and because bigh

horizontal force production is demanded (24), agility

movements likely involve tbese same components. In ad-

dition, it appears tbat a significant inverse relationsbip

exists between ground contact time and maximum sprint

velocity (31), suggesting that tbe requisite force needs to

be reached in a short peiiod during sprinting. Tbis can

also be related to quick contact phases during COD. As

for predictors of sprinting performance, Costill and col-

leagues (5) found a significant correlation between sprint

and vertical jump tests, suggesting that vertical force pro-

duction may be crucial to sprinting. Wisloff and others

(30) also demonstrated that both sprinting performance

and vertical jump beigbt significantly correlate witb dy-

namic maximum strength, Mero and others (18) found a

correlation between jumping performance and maximal

running velocity, as well as a strong correlation of bigh

fast twitcb muscle fiber content and maximal running ve-

locity. Findings concerning these relationships have been

somewbat equivocal; a recent study (14) analyzed maxi-

mum speed, agility, and acceleration and found these 3

qualities to be relatively unrelated.

Otber investigations bave correlated agility type tests

witb eitber speed or jumping tests. One agility-related

investigation (23) found that T-test performance could be

predicted from leg power, leg speed, and agility, again

suggesting a relationship between sprinting cbaracteris-

tics and agility. Another study (34) compared a drop jump

(DJ) test witb 8 difTerent COD tests consisting of varying

distances, turns, and straigbt sprints and suggested tbat

tbe DJ test was significantly correlated witb both straight

sprinting speed and COD speed due to a similarity in the

pusbing-off actions. These studies suggest that a relation-

ship exists, but tbere is a relative paucity of data con-

cerned directly witb agility performance,

Tbe lack of data in tbe area of testing and training

agility for court sports suggests a need for more research.

Furthermore, given tbat tbese sports frequently use only

short sprints (approximately 5 m) and many sbarp turns,

the utilization of an agility test mimicking tbese charac-

teristics would likely be ideal. It appears tbat no test of

the like has been used in scientific researcb witb sensitive

measures of ground reaction forces. Tberefore, the pur-

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COD AND JUMPING IN FEMALE VOLLEYBALL PLAYKRS 11

Unix

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oiepluol D

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01Uuiucins

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FIGURE

1.

Theoretical model indicating

the

main factorH

in

determining agility.

pose

of

this investigation

was to

describe jumping

and

a^nlity performance in female collegiate volleyball play-

e r s distinguisb betweenthevertical and horizontal forces

during

a COD

movement,

and

correlate agility perfor-

mance witb force-time variables from vertical jump

and

isometric leg extensor performance. We hypothesized that

tbe majority of the total force duringaCOD movement

would

be

vertical

and

that vertical jumps

and

isometric

leg extensor actions would be highly related to agility per-

formance.

METHODS

Experimental pproach

to the

Problem

This investigation involved

a

comparison of National Col-

legiate Athletic Association (NCAA) Division

I.

II.

and III

female volleyball athletes,aswellas acorrelational study

oftherelationship between aspecific testofagilityand

several performance variables

in the

vertical domain.

Ki-

netic properties

of

foot contact during COD were also

ex-

amined.Atest-retest designwasincorporated toassess

the reliahility andprecision of thevarious performance

variahles

so

that only appropriate ones would

be

consid-

eredin theoverall investigation.Theagility test wasde-

signed toreflect theshort distanceandvery sbarp turns

typically involved

in

court sports.

Subjects

A groupof29 female collegiate volleyball players volun-

teered

for

this study before preseason training. Athletes

from Division

I

in=9),

II

In=11),

and III

in

= 9)

teams

participated. Descriptive data foreach grouparesbown

in Table 1.Subjects bad similar training programsin-

volving botb

COD

drills

and

free-weight

and

machine

training. Health history

and

physical activity question-

naires were completedby allsubjects priortotestingto

determine eligibility. All procedures were approved by

the

University Institutional Review Board

for

Human

Sub-

jects Research. Subjects were required

to

attend

3 ses-

sions involving testingofvertical jump, agility,and iso-

metric leg extensor action performance. During the initial

visit, subjects were allowed

to

practice

all

procedures after

providing written informed consent.Thenext2sessions

were identical, consistingof2 trialsofeach performance

TABLE

1.

Comparison

of

National Collegiate AthleticAsso-

ciation divisions mean

SD).

Variable

Division

I

= 9

Division11

- 11)

DivisionIII

= 9

A ge

Height(cm)

Weight(kg)

20 . 3

1.5

177 . 9

6.3

73 . 3

7.7

19 .6

1.4

174 . 3

7.7

71 . 5

9.8

2 0 . 0

1.3

171 . 0

8.0

6 9 . 8

6.9

FIGURE2. Force platform setup. The force platformisad-

hered to the

floor,

and

the

platform

is

built around

it.

test.

The

best trial

for

each performance test during

t

session wasused foranalysis,and test-retest reliabili

was establisbed hetweenthesecondandtbird testing se

sion. Test order was counterbalanced

for all

subjects, a

a minimum

of 3

days separated eacb session. Subje

were instructed towearthesame footwearfor alltesti

sessions.

Procedures

Agility Test

Theagility test wascompleted on a 6-m

1-m

custom-designed testing platform (Figure

2)

with

built-in AMTI multidimensional force platfor

(,BP60090(); Watertown, MA).Tbeforce platformwas

terfaced to a PC via a 12-bit analog-digital conver

(PCI-DAS

1200;

Measurement Computing, Middlebo

MA)

in

order

to

collect force-time data. Data were

sa

pledat1.000 Hz,and theforce signal was smoothed usi

a fourth-order recursive low-pass Butterworth filter wi

a cutoff frequency of

5 0

Hz. Tbe 5-meter agility test sta

flnish was marked directly over tbecenterof tbefo

platform.The.suhjects beganthetest with theright fo

on

the

force platform. Upon

a

verbal signal,

the

subj

pivoted on

tbe

left foot and sprinted 5 meters, planted

t

left foot, then turned 180'' to theright, changing to

opposite direction,andsprinted backto theforce platfo

(Figure 3).

The

subject next planted

tbe

right foot on

t

force platform, turned 180

to the

left,

and

changed

d

rectionsto thecontralateral side, using theleft foot

the first step in the new direction. The subject th

sprinted back, with another

180'

rigbt turn, changing

the opposite direction. Last,

tbe

subject finished

the

t

by sprinting

5

meters back

to the

start

by

running ov

the force platform with one foot, thereby stoppingt

test.

Two

trials were performed,

and the

trial with

t

best time from toe-off to beel-down of tbe last foot cont

Sm

- 4

- -

t

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1194 BARNES, SCHILLING, FALVOET AL.

TABLE2. Performance variab lesbydivision.*

Variable

DivisionI{n- 9)

Division

ll (n =

11) DivisionIII

in

- 9)

TIME(s)

VFORCE(N)

HFORCE(N)

CMHT (cm)

DJCT (s)

DJHT (cm)

DJRSI(ems'

PF( N)

5,93 0.2

1,487.3 237.0

666.7 86.7

36.4 2.5t

0.42 0.9

36.0

1.3

87.2 18.5

1,374.6

196.6

6.00 0.2

1,495.4 339.3

620.0 93.4

31.8 4.6

0.42 0.6

32.1

4.9

78.1 15.9

1,260.7

393.0

6.1 0.2

1,335.3 196.7

614.9 98.6

30.2 7.2

0.44 0.5

32.6

5.1

72.7 14.5

1,523.9 350.3

TIME- total agility test time; VFORCE- vertical force during change of direction; HFORCE- horizontal force durin g chan

of direction; CMHT = countennovement jump height; DJCT= drop jump ground contact time; DJHT=drop jump height; DJR

= drop jum p rea ctive s treng th index;

PF ^

isometric

leg

extensor action peak force.

t p