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Corrigendum to “Postural stability during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects” [Clin. Biomech. 30 (2015) 283–289]
Clinical Biomechanics 30 (2015) 765–767
Contents lists available at ScienceDirect
Clinical Biomechanics journal homepage: www.elsevier.com/locate/clinbiomech
Corrigendum
Corrigendum to “Postural stability during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects” [Clin. Biomech. 30 (2015) 283–289] Bart Dingenen a,⁎, Luc Janssens b,c, Thomas Luyckx d, Steven Claes d,e, Johan Bellemans d, Filip F. Staes a a KU Leuven, Musculoskeletal Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Tervuursevest 101 b1501, 3001 Heverlee, Belgium b KU Leuven, Department of Electrical Engineering, Faculty of Engineering Technology Services, Andreas Vesaliusstraat 13, 3000 Leuven, Belgium c KU Leuven, Cardiovascular and Respiratory Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Tervuursevest 101 b1501, 3001 Heverlee, Belgium d Department of Orthopedics, University Hospitals Leuven, Campus Pellenberg,Weligerveld 1, 3212 Pellenberg, Belgium e Department of Orthopedic Surgery, AZ Herentals Hospital, Nederrij 133, 2200 Herentals, Belgium
Table 2 P-values of all group, vision and group-vision interaction effects of all postural stability parameters.
The authors regret to inform that we discovered a scaling error in the absolute values where center of pressure distances were involved, presented in our paper “Postural stability during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects”. Even though previous internal and external reviews didn't mention this possible error, our research team very recently (March 2015) discovered this as we started up a multilaboratory trial. It is important to emphasize that after a thorough check-up and reanalyses of all trials included in this study, this scaling error did not affect the final conclusions and interpretations of this study. However, from a scientific integrity point of view, we do feel that it is important to inform about this and publish a corrigendum with correct absolute values, figures and tables in order to allow comparability in future studies by other colleagues and avoid any misunderstandings. A corrigendum to the paper where the methodology used in this paper was developed and described in more detail (Dingenen et al. 2013, Journal of Biomechanics, 46 (13); 2213–2219) was recently also published (doi: 10.1016/j.jbiomech.2015.05.003). The minor changes in the P-values presented in the Results Section (3.2.1) were corrected where necessary. The group effect of the outcome “Mean absolute COP velocity during IP” is now significant,
while this outcome was marginally significant in the original published paper. However, this finding did not affect the interpretation of the results of this study, as all post-hoc results were the same. The P-values presented in Table 2, and all data in Table 3 were corrected. In addition, Figs. 2–3 were corrected. Based on the small changes in the P-values, some additional information was added in the figure caption of Fig. 2.
DOI of original article: http://dx.doi.org/10.1016/j.clinbiomech.2015.01.002. ⁎ Corresponding author. E-mail addresses: [email protected] (B. Dingenen), [email protected] (L. Janssens), [email protected] (T. Luyckx), [email protected] (S. Claes), [email protected] (J. Bellemans), fi[email protected] (F.F. Staes).
3.2.1. Differences between groups and vision conditions A significant group effect was found for COP displacement during TAT (P = .001) and mean absolute COP velocity during IP (P = .041) (Table 2). Post-hoc analysis showed a significantly increased COP displacement during TAT in the ACLI group compared to the control group when eyes were closed (P b .001) (Fig. 2C). Significant vision effects were found for contralateral push-off duration (P = .023), contralateral push-off COP excursion (P = .018), contralateral push-off COP displacement (P = .006), peak COP velocity (P = .002), mean absolute COP velocity during IP (P b .001) and COP displacement during TAT (P b .001) (Table 2). Post-hoc analysis showed that the mean absolute COP velocity during IP (P = .002 for
http://dx.doi.org/10.1016/j.clinbiomech.2015.05.011 0268-0033/© 2015 Elsevier Ltd. All rights reserved.
Contralateral push-off duration Contralateral push-off COP excursion Contralateral push-off COP displacement Peak COP velocity Time to new stability point Mean absolute COP velocity during IP COP displacement during TAT
Group effect
Vision effect
Group-vision interaction effect
.296 .815 .609 .841 .814 .041* .001*
.023* .018* .006* .002* .321 b .001* b .001*
.934 .320 .331 .267 .452 .167 .020*
COP: center of pressure; IP: intermediate phase; TAT: three seconds after time to new stability point. * Significant at P b .05.
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B. Dingenen et al. / Clinical Biomechanics 30 (2015) 765–767
Table 3 Differences between legs for eyes open and eyes closed conditions within both groups. Control group
ACLI group
EYES OPEN
Preferred
Non-preferred
P-value
Injured
Non-injured
P-value
Contralateral push-off duration (s) (M (SD)) Contralateral push-off COP excursion (m) (M (SD)) Contralateral push-off COP displacement (m) (M (SD)) Peak COP velocity (m/s) (M (SD)) Time to new stability point (s) (M (SD)) Mean absolute COP velocity during IP (m/s) (M (SD)) COP displacement during TAT (m) (M (SD))
0.49 (0.07) 0.04 (0.01) 0.09 (0.02) 0.62 (0.16) 5.50 (1.32) 0.09 (0.02) 0.14 (0.02)
0.52 (0.07) 0.04 (0.01) 0.08 (0.02) 0.58 (0.11) 5.11 (1.55) 0.09 (0.01) 0.14 (0.03)
.228 .303 .296 .428 .423 .953 .577
0.48 (0.06) 0.04 (0.01) 0.09 (0.03) 0.60 (0.20) 4.43 (1.75) 0.11 (0.03) 0.19 (0.04)
0.47 (0.08) 0.04 (0.02) 0.09 (0.03) 0.61 (0.22) 4.18 (1.71) 0.12 (0.04) 0.19 (0.05)
.630 .434 .289 .960 .633 .429 .695
EYES CLOSED
Preferred
Non-preferred
P-value
Injured
Non-injured
P-value
Contralateral push-off duration (s) (M (SD)) Contralateral push-off COP excursion (m) (M (SD)) Contralateral push-off COP displacement (m) (M (SD)) Peak COP velocity (m/s) (M (SD)) Time to new stability point (s) (M (SD)) Mean absolute COP velocity during IP (m/s) (M (SD)) COP displacement during TAT (m) (M (SD))
0.51 (0.08) 0.04 (0.02) 0.08 (0.03) 0.53 (0.18) 5.40 (1.80) 0.12 (0.04) 0.28 (0.08)
0.54 (0.09) 0.03 (0.01) 0.07 (0.02) 0.49 (0.16) 5.23 (1.91) 0.12 (0.03) 0.26 (0.05)
.247 .325 .350 .498 .780 .490 .249
0.52 (0.07) 0.04 (0.01) 0.09 (0.03) 0.56 (0.19) 5.05 (2.21) 0.16 (0.04) 0.38 (0.13)
0.50 (0.08) 0.04 (0.02) 0.08 (0.04) 0.49 (0.26) 4.70 (1.84) 0.15 (0.04) 0.39 (0.11)
.493 .252 .130 .152 .485 .641 .695
ACLI: anterior cruciate ligament injured; M: mean; SD: standard deviation; COP: center of pressure; IP: intermediate phase; TAT: three seconds after time to new stability point.
the control group, P b .001 for the ACLI group) and COP displacement during TAT were significantly increased within both groups during eyes closed compared to eyes open (P b .001) (Fig. 2BC), while the
Fig. 2. Differences between groups and vision conditions (post-hoc results) for the time to new stability point (TNSP) (A), mean absolute COP velocity during the intermediate phase (IP) (B), and the COP displacement during the first three seconds after TNSP (TAT) (C). Data are presented as means and associated standard deviations. EO: eyes open; EC: eyes closed; ** Significant at P b 0.01; *** Significant at P b 0.001.
contralateral push-off COP displacement (P = .044) and peak COP velocity (P = .016) were significantly decreased compared to eyes open for the control group (Fig. 3CD). No significant differences between groups or vision conditions were found for TNSP (Fig. 2A), contralateral push-off COP duration and contralateral push-off COP excursion (Fig. 3AB) (P > .05). A significant group-vision interaction effect was found for COP displacement during TAT (P = .020) (Table 2). The authors would like to apologize for any inconvenience caused.
B. Dingenen et al. / Clinical Biomechanics 30 (2015) 765–767
Fig. 3.
767
Contents lists available at ScienceDirect
Clinical Biomechanics journal homepage: www.elsevier.com/locate/clinbiomech
Corrigendum
Corrigendum to “Postural stability during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects” [Clin. Biomech. 30 (2015) 283–289] Bart Dingenen a,⁎, Luc Janssens b,c, Thomas Luyckx d, Steven Claes d,e, Johan Bellemans d, Filip F. Staes a a KU Leuven, Musculoskeletal Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Tervuursevest 101 b1501, 3001 Heverlee, Belgium b KU Leuven, Department of Electrical Engineering, Faculty of Engineering Technology Services, Andreas Vesaliusstraat 13, 3000 Leuven, Belgium c KU Leuven, Cardiovascular and Respiratory Rehabilitation Research Group, Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences, Tervuursevest 101 b1501, 3001 Heverlee, Belgium d Department of Orthopedics, University Hospitals Leuven, Campus Pellenberg,Weligerveld 1, 3212 Pellenberg, Belgium e Department of Orthopedic Surgery, AZ Herentals Hospital, Nederrij 133, 2200 Herentals, Belgium
Table 2 P-values of all group, vision and group-vision interaction effects of all postural stability parameters.
The authors regret to inform that we discovered a scaling error in the absolute values where center of pressure distances were involved, presented in our paper “Postural stability during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects”. Even though previous internal and external reviews didn't mention this possible error, our research team very recently (March 2015) discovered this as we started up a multilaboratory trial. It is important to emphasize that after a thorough check-up and reanalyses of all trials included in this study, this scaling error did not affect the final conclusions and interpretations of this study. However, from a scientific integrity point of view, we do feel that it is important to inform about this and publish a corrigendum with correct absolute values, figures and tables in order to allow comparability in future studies by other colleagues and avoid any misunderstandings. A corrigendum to the paper where the methodology used in this paper was developed and described in more detail (Dingenen et al. 2013, Journal of Biomechanics, 46 (13); 2213–2219) was recently also published (doi: 10.1016/j.jbiomech.2015.05.003). The minor changes in the P-values presented in the Results Section (3.2.1) were corrected where necessary. The group effect of the outcome “Mean absolute COP velocity during IP” is now significant,
while this outcome was marginally significant in the original published paper. However, this finding did not affect the interpretation of the results of this study, as all post-hoc results were the same. The P-values presented in Table 2, and all data in Table 3 were corrected. In addition, Figs. 2–3 were corrected. Based on the small changes in the P-values, some additional information was added in the figure caption of Fig. 2.
DOI of original article: http://dx.doi.org/10.1016/j.clinbiomech.2015.01.002. ⁎ Corresponding author. E-mail addresses: [email protected] (B. Dingenen), [email protected] (L. Janssens), [email protected] (T. Luyckx), [email protected] (S. Claes), [email protected] (J. Bellemans), fi[email protected] (F.F. Staes).
3.2.1. Differences between groups and vision conditions A significant group effect was found for COP displacement during TAT (P = .001) and mean absolute COP velocity during IP (P = .041) (Table 2). Post-hoc analysis showed a significantly increased COP displacement during TAT in the ACLI group compared to the control group when eyes were closed (P b .001) (Fig. 2C). Significant vision effects were found for contralateral push-off duration (P = .023), contralateral push-off COP excursion (P = .018), contralateral push-off COP displacement (P = .006), peak COP velocity (P = .002), mean absolute COP velocity during IP (P b .001) and COP displacement during TAT (P b .001) (Table 2). Post-hoc analysis showed that the mean absolute COP velocity during IP (P = .002 for
http://dx.doi.org/10.1016/j.clinbiomech.2015.05.011 0268-0033/© 2015 Elsevier Ltd. All rights reserved.
Contralateral push-off duration Contralateral push-off COP excursion Contralateral push-off COP displacement Peak COP velocity Time to new stability point Mean absolute COP velocity during IP COP displacement during TAT
Group effect
Vision effect
Group-vision interaction effect
.296 .815 .609 .841 .814 .041* .001*
.023* .018* .006* .002* .321 b .001* b .001*
.934 .320 .331 .267 .452 .167 .020*
COP: center of pressure; IP: intermediate phase; TAT: three seconds after time to new stability point. * Significant at P b .05.
766
B. Dingenen et al. / Clinical Biomechanics 30 (2015) 765–767
Table 3 Differences between legs for eyes open and eyes closed conditions within both groups. Control group
ACLI group
EYES OPEN
Preferred
Non-preferred
P-value
Injured
Non-injured
P-value
Contralateral push-off duration (s) (M (SD)) Contralateral push-off COP excursion (m) (M (SD)) Contralateral push-off COP displacement (m) (M (SD)) Peak COP velocity (m/s) (M (SD)) Time to new stability point (s) (M (SD)) Mean absolute COP velocity during IP (m/s) (M (SD)) COP displacement during TAT (m) (M (SD))
0.49 (0.07) 0.04 (0.01) 0.09 (0.02) 0.62 (0.16) 5.50 (1.32) 0.09 (0.02) 0.14 (0.02)
0.52 (0.07) 0.04 (0.01) 0.08 (0.02) 0.58 (0.11) 5.11 (1.55) 0.09 (0.01) 0.14 (0.03)
.228 .303 .296 .428 .423 .953 .577
0.48 (0.06) 0.04 (0.01) 0.09 (0.03) 0.60 (0.20) 4.43 (1.75) 0.11 (0.03) 0.19 (0.04)
0.47 (0.08) 0.04 (0.02) 0.09 (0.03) 0.61 (0.22) 4.18 (1.71) 0.12 (0.04) 0.19 (0.05)
.630 .434 .289 .960 .633 .429 .695
EYES CLOSED
Preferred
Non-preferred
P-value
Injured
Non-injured
P-value
Contralateral push-off duration (s) (M (SD)) Contralateral push-off COP excursion (m) (M (SD)) Contralateral push-off COP displacement (m) (M (SD)) Peak COP velocity (m/s) (M (SD)) Time to new stability point (s) (M (SD)) Mean absolute COP velocity during IP (m/s) (M (SD)) COP displacement during TAT (m) (M (SD))
0.51 (0.08) 0.04 (0.02) 0.08 (0.03) 0.53 (0.18) 5.40 (1.80) 0.12 (0.04) 0.28 (0.08)
0.54 (0.09) 0.03 (0.01) 0.07 (0.02) 0.49 (0.16) 5.23 (1.91) 0.12 (0.03) 0.26 (0.05)
.247 .325 .350 .498 .780 .490 .249
0.52 (0.07) 0.04 (0.01) 0.09 (0.03) 0.56 (0.19) 5.05 (2.21) 0.16 (0.04) 0.38 (0.13)
0.50 (0.08) 0.04 (0.02) 0.08 (0.04) 0.49 (0.26) 4.70 (1.84) 0.15 (0.04) 0.39 (0.11)
.493 .252 .130 .152 .485 .641 .695
ACLI: anterior cruciate ligament injured; M: mean; SD: standard deviation; COP: center of pressure; IP: intermediate phase; TAT: three seconds after time to new stability point.
the control group, P b .001 for the ACLI group) and COP displacement during TAT were significantly increased within both groups during eyes closed compared to eyes open (P b .001) (Fig. 2BC), while the
Fig. 2. Differences between groups and vision conditions (post-hoc results) for the time to new stability point (TNSP) (A), mean absolute COP velocity during the intermediate phase (IP) (B), and the COP displacement during the first three seconds after TNSP (TAT) (C). Data are presented as means and associated standard deviations. EO: eyes open; EC: eyes closed; ** Significant at P b 0.01; *** Significant at P b 0.001.
contralateral push-off COP displacement (P = .044) and peak COP velocity (P = .016) were significantly decreased compared to eyes open for the control group (Fig. 3CD). No significant differences between groups or vision conditions were found for TNSP (Fig. 2A), contralateral push-off COP duration and contralateral push-off COP excursion (Fig. 3AB) (P > .05). A significant group-vision interaction effect was found for COP displacement during TAT (P = .020) (Table 2). The authors would like to apologize for any inconvenience caused.
B. Dingenen et al. / Clinical Biomechanics 30 (2015) 765–767
Fig. 3.
767