european college of sport science

Friday, June 26th, 2009
Subjects: three males aged 66-68 years No. of experiments: 11times (at 2-month intervals)
MRI device: AIRIS II (Hitachi Medicon, Inc.)
Analytical software: Aquarius NetStation Version 1.1 (Terarecon Inc.)
Measuring instrument for hip-joint muscle strength: Newly developed exclusively for the study
Results: The study revealed significant correlations between abductor force during outward rotation of the hip joint muscles and the left
and right psoas major and erector spinae muscles (r = 0.595, 0.514, 0.611 and 0.726 respectively; p < 0.01).
Observations
the study indicated the possibility that the torque values of hip joint muscles can be used effectively as a substitute measure for evaluating
the strengths of the psoas major and erector spinae muscles, which are not readily accessible for muscle strength evaluation.
References
1) Yamamoto Tadahiro et al. M.psoas major muscle power evaluation measurment device&#12289;The14th 3)about
the&#12288;masurement of the torque-Comparative study of student and the middle&#12288;aged&#12289;The10th European College
of Sport Science(ECSS)&#12289;Belgrad&#12289;Aug&#12289;2005
2) Yamamoto Tadahiro et al. Study Regarding Torque Measurements, The 13th European College of Sport Science (ECSS), Estoril-Portugal,
Jul, 2008
3) Aoyama Hareo et al. Research on Torque Measurement, The 13th European College of Sport Science (ECSS), Estoril-Portugal, Jul, 2008
QUANTITATIVE ULTRASOUND OF THE GASTROCNEMIUS MUSCLE ARCHITECTURE IN CHILDREN: VARIABILITY, RELI-
ABILITY, AND COMPARISON BETWEEN PORTABLE AND STATIONARY MACHINES
LEGERLOTZ, K., SMITH, H.K., HING, W.A.
QUEEN MARY, UNIVERSITY OF LONDON
Muscle architecture is believed to be affected by muscular disorders, including the chronic spasticity associated with cerebral palsy.
Although there is clear evidence that muscle thickness is reduced with spastic cerebral palsy in children and adults, the effects of spasticity
on other parameters of muscle architecture remain unclear. However, a high biological and/or methodological variability might explain
why differences in muscle fiber length or pennation angle between groups of individuals might be difficult to detect. This may be
particularly important in children due to their smaller muscles and potential difficulty in remaining still. The first aim of this study was
therefore to determine the inter-leg and inter-individual variability in ultrasound measurements of gastrocnemius muscle architecture in
young children. Our second aim was to establish within-session and between-session reliability of measurements for the same child.
Third, we compared measurements obtained using a stationary ultrasound (Phillips HD11) with those obtained using a less costly and
portable machine (Chison 8300) to evaluate the appropriateness of a more widely accessible and practical option for the quantification of
gastrocnemius muscle architecture in children.
Muscle thickness, pennation angle and fiber length of the medial gastrocnemius were determined in healthy children (13 boys, 8 girls)
aged 4-10 years. Ultrasound images were obtained from each leg, twice at each of two ankle positions (90º and maximal plantar flexion),
and with each of the two machines in succession, within the same session. The same measurements were made on a second
occasion, between 4 and 6 weeks later, in 4 of the children.
There was no significant difference between the absolute values, coefficients of variation (CV) or intra-class correlation coefficients (ICC) of
measurements determined by the two ultrasound machines. The CV and ICC of duplicate images taken during the same session for the
same leg, ankle position, and machine ranged from 2.1-3.1% and 0.94-0.98 for muscle thickness, 4.1-6.0% and 0.85-0.96 for pennation
angle, and 4.5-6.3% and 0.87-0.96 for fiber length, similar to that reported previously for adult muscle architecture. CV for variables for
the same child measured on two separate sessions were within the same ranges. There was wide inter-individual variability at both
ankle positions for pennation angle (range 11-22°), fiber length (26-68mm) and muscle thickness (26-68mm).
Since the CVs for repeated measurements within a subject (2.3-6.3%) were much less than the group SD relative to the mean for the
same measurement (13-25%), we suggest that the variability attributable to the methods is acceptable given the biological variation seen.
We conclude that the portable ultrasound is suitable to determine muscle architecture and that thickness, pennation angle and fiber
length can be reliably determined in the gastrocnemius muscle of young children.
TRI-AXIAL INERTIAL MAGNETIC TRACKING DETECTS CHRONIC ANKLE INSTABILITY.
MARTÍNEZ, A., LECUMBERRI, P., GÓMEZ, M., MORANT, M., MENDIGUCHÍA, J., IZQUIERDO, M.
CENTRO DE ESTUDIOS, INVESTIGACIÓN Y MEDICINA DEL DEPORTE
Introduction: Ankle sprains are one of the most common lower extremity injuries. Real time human motion tracking is an accurate, inexpensive
and portable system to obtain kinematic and kinetic measurements (2). The purpose of this study was to discriminate between
subjects with chronic ankle instability (CAI) and subjects with stable ankles through inertial/magnetic tracking technology.
Methods: Twelve subjects (23.16 ± 5.32 years, 174.83 ± 8.78 cm, and 73.58 ± 17.10 kg) with stable ankles and thirteen (24.69 ± 5.91 years,
173.31 ± 9.07 cm, and 69.61 ± 15.32 kg) with chronic ankle instability performed the Star Excursion Balance Test (SEBT) (1). The SEBT is a
dynamic postural control task that may hold promise in detecting deficits related to CAI (1). The subjects complete anterior (A), posteromedial
(PM), and posterolateral (PL) reaching directions of the SEBT. Static force platform (IBV, Valencia, Spain) and a body-mounted sensor
MTx (Xsens Technologies B.V. Enschede, Netherlands) were used to record simultaneously force, acceleration and orientation data. The
inertial motion tracking was placed close to the centre of mass, which is located within the pelvis with the aim of study `whole-body´
movements. Wavelet analyse based on time–frequency information was used for analysing all signals (2-3).
Results: CAI group showed greater (81%) values than the stable ankle group both in the peak amplitude of the approximation signal of
the rotation around the z-axis (p=0.053) in the A direction and in the peak amplitude of the approximation signal (102%) of the rotation
around the x-axis (p=0.086) in the PM direction. No significant differences were observed in the other orientation parameters. The approximation
of the z acceleration coordinate signal (p=0.014) showed significant differences between groups. In addition, there were
significant differences in the sum of the coefficients of the details 1 (p=0.02) and details 2 (p=0.007) of the y acceleration coordinate signal.
When the corresponding analyses were performed from the force plate measurements no significant differences were observed between
groups.
Discussion: The rotation around the z-axis and the x-axis acquired from the MTx unit discriminated differences between groups. The
wavelet details of the y acceleration coordinate signal were the most accurate parameters discriminating between ankle groups. How-
OSLO/NORWAY, JUNE 24-27, 2009 365