european college of sport science

Friday, June 26th, 2009
nation, strength endurance, anaerobic shuttle run and Cooper test. Based on these tests, norm profiles were established in all age
groups. In case of an ACL injury the last test result before the injury was compared with the norm values. Over the 10 year period 39
female and 18 male athletes sustained an ALC injury. Z score transformations for all variables normalized the different age groups. Ttests
were used to calculate performance differences between injured and non-injured athletes.
RESULTS: Injured female athletes had lower performance in strength endurance (p=0.031), maximum relative isometric core extension
strength (p=0.030) and core/leg strength ratio (p=0.039). In injured male ski racers maximum absolute & relative core flexion strength
(p=0.032/p=0.030), jump coordination (p=0.017) and drop jump height (p=0.042) were lower than in non-injured athletes. Injured males
had longer drop jump contact time (p=0.005). The calculated parameter of core flexion to extension ratio was also lower (p=0.009) in
injured males.
DISCUSSION: Core strength is fundamental in ski racing for body stabilisation and force generation. Leetun et al. (2004) have noted that
decreased core stability contributes to lower extremity injuries. In this study core strength, core/leg strength ratio and core flexion/extension
strength ratio seems to be a critical factor for ACL injuries. Knee injury prevention must improve strength capacity and
neuromuscular patterns in leg and core muscles (Hewett et al. 1999). Enhanced incorporation of fatigue resistance training in female and
specific plyometric training programs coupled with unanticipated event management in male athletes are recommended. The longitudinal
examination of physical fitness provides ski coaches with helpful information to develop more effective injury prevention programs.
REFERENCES
Pujol et al., Am. J. Sports Med. 35(7): 1071-1074; 2007
Leetun et al., Med. Sci. Sports Exerc. 36(6), 926-934, 2004
Hewett et al., Am. J. Sports Med. 27(6), 699-706, 1999
RELIABILITY OF SINGLE-LEG AND DOUBLE-LEG BALANCE TESTS IN SUBJECTS WITH ANTERIOR CRUCIATE LIGAMENT
RECONSTRUCTION AND CONTROLS
KOUVELIOTI, V., KELLIS, E.
ARISTOTLE UNIVERSITY OF THESSALONIKI
Balance assessment and training are important elements of rehabilitation following anterior cruciate ligament (ACL) reconstruction.
Assessment of balance in double and single-limb stance involves recording of the movement of the centre of pressure (COP) using various
platforms. It is important to ensure that the assessment tools we use in the clinical setting and in research have minimal measurement
error (Ageberg 2007). Translating reliability coefficients into clinically meaningful representations of measurement error is a necessary
and important step when the goal is to link clinical research to clinical practice. Therefore, the aim of this study was to assess the
test-retest reliability of balance variables measured in both and single-limb stance in patients and controls. Fifteen healthy subjects and
ten subjects with ACL reconstruction performed stability tests at two occasions, a week apart. The subjects were instructed to stand erect,
barefoot with feet shoulder width apart with opened eyes for 30 sec. They then performed a single-limb balance test by standing on one
foot with the other leg flexed at 90° at the hip and the knee joints with both arms hanging relaxed at the sides (Ageberg, 2005). The
assessment for both tests, included 3 measurements, and 5-min rest was provided between successive trials. The best trial was further
analyzed. All tests were performed on an EPS pressure platform (Loran Engineering S.r.I., Bologna – Italy). The COP was recorded at 30 Hz
and it was used to estimate the total path of the COP, the COP standard deviation in the anteroposterior and mediolateral axis, the velocity
of the COP in both axis, the sway area and the ellipse formulated by the COP trajectory paths over time. For the total COP path, the
intraclass correlation coefficient (ICC) ranged from 0.71 to 0.83. For the COP standard deviation the ICCs ranged from 0.74 to 0.94. For the
COP speed, the ICCs ranged from 0.65 to 0.79. The sway area and ellipse scores displayed ICCs values of 0.91 to 0.95 and 0.86 to 0.92,
respectively. In general, the ICCs were higher for double leg tests compared with single-stance ones. The above results indicate that 30-s
balance tests in double and single-leg stance are reliable tools to assess static balance. Consequently, the use of such tests to monitor
rehabilitation programs following ACL reconstruction is recommended.
References
Ageberg E, Flenhagen J, Ljung J. (2007). BMC Musculoskelet Disord, 8:57.
Ageberg E, Roberts D, Holmstrom E, Friden T. (2005). Am J Sports Med 33(10):1527-1535.
CROSS ECCENTRIC EXERCISE IMPROVES ACCELERATION REACTION TIME AND SUBJECTIVE SCORES ON QUADRICEPS
FOLLOWING ACL RECONSTRUCTION
PAPANDREOU, M., PAPATHANASIOU, G., GEORGOUDIS, G., SPYROPOULOS, P., BILLIS, E., PAPAIOANNOU, N.
TECHNOLOGICAL EDUCATION INSTITUTE (TEI)
Purpose
Anterior cruciate ligament (ACL) reconstruction can cause knee impairments and disability. Knee impairments are related to quadriceps
performance - accelerated reaction time (ART) - and disability to performance of daily living activities which is assessed by questionnaires
(Lysholm knee score). The purposes of this study were to investigate the effect of cross exercise to the early rehabilitation phase of ACL
reconstruction: a) on quadriceps ART at 450, 600 and 900 of knee flexion and, b) on the subjective scores of disability in ACL reconstructed
patients.
Methods
42 patients who underwent ACL reconstruction were randomly divided into 3 groups, two experimental and one control. All groups
followed the same rehabilitation program. The experimental groups followed 8 weeks of cross eccentric exercise (CEE) on the uninjured
knee; 3d/w, and 5d/w respectively.
Quadriceps ART was measured at 450, 600 and 900 of knee flexion pre and nine weeks post-operatively using an isokinetic dynamometer.
Patients completed pre and post operatively the Lysholm questionnaire whereby subjective scores were recorded.
Results: Two factor ANOVA showed significant differences in ART at 900 among the groups (F=4.29, p=0.02, p