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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
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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
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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