Aula Minor Chairs: Davide Cattaneo, Maria Grazia Benedetti
15:00-15:10 A QUANTITATIVE METHOD TO ESTIMATE LOWER BACK REPOSITIONING BY MEANS OF A SINGLE INERTIAL SENSOR
I. Parel, A. Sassoli, L. Palmerini, S. Mellone, C. Tacconi, M. Branchini, M. Giacobazzi, L. Chiari, U. Van Daele
15:10-15:20 RADIOGRAPHIC EVALUATION OF AN ENHANCED TRUNK MARKER SET IN PATIENTS WITH ADOLESCENT IDIOPATHIC SCOLIOSIS
S. Schmid, S. Lorenzetti, C. Hasler, J. Romkes, W. Taylor, R. Brunner
15:20-15:30 COORDINATION OF THE HIP AND LUMBAR SPINE DURING SIT-TO-STAND IN HEALTHY SUBJECTS K. Widhalm, T. Stamm, E.J. Hurkmans
15:30-15:40 POST-ACUTE REHABILITATION AND FOLLOW-UP IN ISCHEMIC SPINAL CORD INJURY IN CHILDHOOD: A CASE REPORT
M.L. Salsano, A. Pisano, M. Petrarca, A. Maggi, G. Mosiello, E. Castelli
15:40-15:50 EFFECT OF MONO- OR BISEGMENTAL SPINAL FUSION SURGERY (L3 – S1) ON TRUNK RANGE OF MOTION AND GAIT PERFORMANCE
F. Stief, M. Rickert, J. Wienand, M. Rauschmann, A. Meurer
15:50-16:00 TEST-RETEST RELIABILITY OF THREE-DIMENSIONAL GAIT ANALYSIS IN CHRONIC LOW BACK PAIN INDIVIDUALS: A PRELIMINARY STUDY
R. Fernandes, V. Moniz-Pereira, A. Veloso, P. Armada-da-Silva
1s t Clinical Movement Analysis World Conference
15thAnnual Meeting of the Italian Society of Clinical Movement Analysis
2 3rdAnnual Meeting of the Euro pean Society for Movement Analysis in Adults and Ch ildren
A QUANTITATIVE METHOD TO ESTIMATE LOWER BACK REPOSITIONING BY MEANS OF A SINGLE INERTIAL SENSOR I.Parel(1,3), A.Sassoli(2),L.Palmerini(3), S.Mellone(3), C.Tacconi(3), M.Branchini(2), M.Giacobazzi(2), L.Chiari(3), U.VanDaele(4) (1) Cervesi Hospital, Motion Analysis Laboratory, Rimini, Italy
(2) University of Bologna, Degree Course in Physiotherapy, Univ.Hospital S. Orsola - Malpighi, Bologna, Italy (3) University of Bologna, DEI and CIRI-SDV, Bologna, Italy
(4) University of Antwerp, Department of Rehabilitation Sciences & Physiotherapy, Antwerp, Belgium Main topics: analysis of clinical movement data; technical developments in movement science INTRODUCTION and AIM
Research has provided evidence on impairments in sensorimotor control of the lower back in low back pain (LBP) patients [1]. Evaluating sensorimotor control is a challenge because of the number of neurophysiologic processes that are involved and the many, sometimes subjective, measurement options that are available. Repositioning tasks are often described to evaluate proprioception in LBP patients [2].
According to Gill and Callaghan [3], the repositioning test (pelvic tilt in four-point-kneeling position) represents a reliable and stable test to assess the proprioception ability in patients with LBP. The estimate of the repositioning accuracy is currently obtained visually by means of a ruler. The aim of this study is to obtain quantitative estimates of lower back repositioning by using a single wearable sensor.
PATIENTS/MATERIALS and METHODS
Eleven healthysubjects were involved in the study.Data were collected by means of a wearable inertial sensing unit(EXEL srl, Bologna, IT) and a motion capture system including 4 optical cameras (VICON-Bonita), which was considered the gold standard (GS).All subjects performed the repositioning test consisting in the following steps: 1) start in neutral position; 2)reach the maximum flexion of the lumbar spine (de-lordosis); 3) reach the maximum extension of the lumbar spine ((de-lordosis);4) back to neutral position (Figure 1).The test outcome is the repositioning error, i.e, the difference in L4 positionbetween 1)and 4). A physical therapist positioned two sensors on L4 and S1.Accuracies were then compared to assess the better positioning for the sensor.The gyroscope was used to segment the 4 phases and the accelerometer was used as an inclinometer.Abiomechanical model describing the relative movement between pelvis and L4 was developed, with the distance between L4 and the coccyx (measured by the physical therapist) as an additional input to the model.
RESULTS
The repositioning error measured with the GS was 1.07 ± 1.00 cm. Root mean squared errors (RMSE) between sensor-based estimates and the GS were 1.04 cm for L4 position and 1.51 cm for S1 position.
DISCUSSION and CONCLUSIONS
In this study a wearable and quantitative tool for the estimate of repositioning error was presented and preliminarily validated. Encouraging results in the accuracy of the sensor estimates were obtained in healthy subjects. The better sensor position was found to be L4. Further validation is needed to assess the accuracy of this tool in LBP patients.
REFERENCES
[1] Allison TG et al. Spine 2003. 15;28(22):2510-6.
[2] Newcomer KL et al. Spine 2000; 25(19): 2488-93.
[3] Gill KP et al. Spine 1998. 23:371-7.
Figure 1: Repositioning test Figure 2 Example of signal processing
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RADIOGRAPHIC EVALUATION OF AN ENHANCED TRUNK MARKER SET IN PATIENTS WITH ADOLESCENT IDIOPATHIC SCOLIOSIS S. Schmid (1,2), S. Lorenzetti (1), C.-C. Hasler (3), J. Romkes (3), W. R. Taylor (1), R. Brunner (3)
(1) ETH Zurich, Institute for Biomechanics, Zurich, Switzerland
(2) Bern University of Applied Sciences, Health Division, Discipline of Physiotherapy, Bern, Switzerland (3) University Children’s Hospital Basel, Orthopedic Department, Basel, Switzerland
Main topics: 1) Orthopaedics, 2) Technical developments in movement science INTRODUCTION and AIM
Standard optical marker sets used for clinical gait analysis (e.g. Plug-in gait) do not allow the quantification of spinal movement. In order to be able to better evaluate pathologies affecting the spine, a previously developed enhanced marker set [1] has been introduced. Due to rotational deformities such as those seen in adolescent idiopathic scoliosis (AIS), however, spinal curvature might be underestimated when derived from the spinous processes [2]. In addition, inaccurate marker placement might further influence curvature estimation. Therefore, the aims of this study were to evaluate 1) the precision of marker placement and 2) the accuracy of sagittal and frontal curvature estimation in the lumbar and thoracic spine.
MATERIALS and METHODS
Eight patients with AIS (age: 14.9±1.4 years; height: 1.67±0.08 m; mass: 57.3±12.6 kg, Cobb angle: 44.5±16.1 degrees) participated in this study. Selected thoracic (T3, T5, T7, T9, T11) and lumbar (L1-5) spinous processes were marked directly on the skin with radio-opaque markers while participants underwent a standard biplanar radiographic examination. Positions of markers, vertebral bodies and spinous processes were extracted using the software ImageJ. Spinal curvature was calculated using a custom-built MATLAB routine. Marker placement error in the horizontal and vertical directions was evaluated using descriptive statistics (median and interquartile range), whereas the accuracy of the curvature estimation was investigated using linear regression analysis.
RESULTS
Marker placement analysis showed horizontal and vertical median deviations of -2.4 mm (IQR: 3.9) and -0.4 mm (IQR: 6.7) for the thoracic and 2.6 mm (IQR: 5.8) and -0.9 mm (IQR: 9.5) for the lumbar spine, respectively (Figure 1). Thoracic curvature angles derived from the markers explained 74.9% (sagittal plane) and 55.3% (frontal plane) of the variance of the curvature angles derived from the vertebral bodies (Figure 2). Slope values of 0.775 and 0.590 further indicated a slight underestimation of the sagittal and moderate underestimation of the frontal curvature, respectively. Only weak estimation accuracy was found for the lumbar spine curvatures.
DISCUSSION and CONCLUSIONS
Marker placement and curvature estimation were found to be more accurate in the thoracic than the lumbar spine. Possible explanations for the lower accuracy in the lumbar spine could be the amount of soft tissue in combination with the lordotic posture. As expected, the frontal curvatures derived from the spinous processes generally underestimated the actual curvature of the spine. These deviations might be corrected using additional radiographic information or by tracking the position of the ribs. In conclusion, the enhanced trunk marker set showed a great potential, especially for the non-invasive assessment of thoracic curvature.
REFERENCES
[1] List R, Gülay T, Stoop M, Lorenzetti S. J Strength Cond Res. 2013;27(6):1529-38.
[2] Herzenberg JE, Waanders NA, Closkey RF, Schultz AB, et al. Spine (Phila Pa 1976). 1990;15(9):874-879.
Figure 1: Placement errors of the lumbar and thoracic markers.
Figure 2: Estimation of the thoracic curvature angles in the sagittal and frontal planes.
1s t Clinical Movement Analysis World Conference
15thAnnual Meeting of the Italian Society of Clinical Movement Analysis
2 3rdAnnual Meeting of the Euro pean Society for Movement Analysis in Adults and Ch ildren
COORDINATION OF THE HIP AND LUMBAR SPINE DURING SIT-TO-STAND IN HEALTHY SUBJECTS K. Widhalm (1), T. Stamm (1, 2), EJ. Hurkmans (1)
(1) FH Campus Wien, Vienna, Austria
(2) Medical University of Vienna, Vienna, Austria
Main topics: Motor control and motor learning, Analysis of gait and motor disorders INTRODUCTION and AIM
The ADL task Sit-to-Stand (STS) has been a focus point in numerous studies [1]. Especially movement behaviour in low-back-pain patients has been investigated in depth. Variability in sagittal spine alignment has been hypothesized to be related with the occurrence of low back pain [2]. However, knowledge concerning different movement patterns in healthy subjects performing STS is missing, making it difficult to conclude whether or not movement patterns are different among low back pain patients. Therefore the objective of this study was 1) to examine the variation in the STS movement in relation to the hip and lumbar spine movements during the last 30% of the total task duration and 2) classifying movement patterns.
PATIENTS/MATERIALS and METHODS
49 healthy subjects (age 11-50 years) performed 6 trials of seat-height normalised STS. Kinematic data were obtained using a 6 camera Vicon system. Main outcome measure was the median of ratios of changes in degrees in sagittal hip and lumbar spine angles. The last 30%
of the total movement was used for this study since in this phase it was expected to find variability differing from literature. For classifying movement patterns a hierarchical cluster analysis was applied. This analysis was applied among three age groups (10-18, 19-30, 31-50 years) to see whether these movement patterns are different between age groups.
RESULTS
The mean values and range for all subjects were 1.89 s [1.46-2.86] for the total task duration, 34.35 % [27.86-42.61] of total task duration for Lift-Off, 83.51° [69.3-101.3] for the hip and 25.1° [11.1-32.9] for the lumbar spine. As result of the hierarchical cluster analysis 3 main types of movement patterns and 3 outliers could be identified. Type I (n=39) is characterised by relatively high contribution of lumbar spine movement during the analysed phase, Type II (n=3) and III (n=4) are more dominated by the movement of the hip and the 3 outliers seem to be caused by measurement problems. These three types of movement were similar among all age groups and also quite similar distributed.
DISCUSSION and CONCLUSIONS
Although the calculation of the index didn´t take into account the differing amount of ROM used (hip : lumbar spine ≈ 3:1), it could be shown that healthy subjects perform STS in different ways. Including the difference of ROM for the Index calculation it can be stated that 80% of the subjects had an lumbar dominated extension in the last 30% of the STS task. Further studies are necessary to analyse factors associated with these different STS patterns and to find possible predictors for the onset of degenerative symptoms in the lower back.
REFERENCES
[1] Tully, E. A., et al. (2005). “Sagittal spine and lower limb movement during sit-to-stand in healthy young subjects.” Gait Posture 22(4): 338-345.
[2] Smith, A., et al. (2008). “Classification of sagittal thoraco-lumbo-pelvic alignment of the adolescent spine in standing and its relationship to low back pain.” Spine 33(19): 2101-2107.
Figure 1: Median ratios of movement pattern type I-III of the last 90-100%, 80-90%, 70-80% of total task duration
Table 1: subject characteristics
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