TY  - GEN
A1  - Sandau, Ingo
A1  - Chaabene, Helmi
A1  - Granacher, Urs
T1  - Concurrent validity of barbell force measured from video-based barbell kinematics during the snatch in male elite weightlifters
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - This study examined the concurrent validity of an inverse dynamic (force computed from barbell acceleration [reference method]) and a work-energy (force computed from work at the barbell [alternative method]) approach to measure the mean vertical barbell force during the snatch using kinematic data from video analysis. For this purpose, the acceleration phase of the snatch was analyzed in thirty male medal winners of the 2018 weightlifting World Championships (age: 25.2±3.1 years; body mass: 88.9±28.6 kg). Vertical barbell kinematics were measured using a custom-made 2D real-time video analysis software. Agreement between the two computational approaches was assessed using Bland-Altman analysis, Deming regression, and Pearson product-moment correlation. Further, principal component analysis in conjunction with multiple linear regression was used to assess whether individual differences related to the two approaches are due to the waveforms of the acceleration time-series data. Results indicated no mean difference (p > 0.05; d = −0.04) and an extremely large correlation (r = 0.99) between the two approaches. Despite the high agreement, the total error of individual differences was 8.2% (163.0 N). The individual differences can be explained by a multiple linear regression model (R2adj = 0.86) on principal component scores from the principal component analysis of vertical barbell acceleration time-series waveforms. Findings from this study indicate that the individual errors of force measures can be associated with the inverse dynamic approach. This approach uses vertical barbell acceleration data from video analysis that is prone to error. Therefore, it is recommended to use the work-energy approach to compute mean vertical barbell force as this approach did not rely on vertical barbell acceleration.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 716 
KW  - Acceleration
KW  - Linear regression analysis
KW  - Velocity
KW  - Principal component analysis
KW  - Kinematics
KW  - Motion
KW  - Scanning electron microscopy
KW  - Computer Software
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-521678
SN  - 1866-8364
IS  - 716
ER  - 
TY  - JOUR
A1  - Sandau, Ingo
A1  - Chaabene, Helmi
A1  - Granacher, Urs
T1  - Concurrent validity of barbell force measured from video-based barbell kinematics during the snatch in male elite weightlifters
JF  - PLOS ONE / Public Library of Science
N2  - This study examined the concurrent validity of an inverse dynamic (force computed from barbell acceleration [reference method]) and a work-energy (force computed from work at the barbell [alternative method]) approach to measure the mean vertical barbell force during the snatch using kinematic data from video analysis. For this purpose, the acceleration phase of the snatch was analyzed in thirty male medal winners of the 2018 weightlifting World Championships (age: 25.2±3.1 years; body mass: 88.9±28.6 kg). Vertical barbell kinematics were measured using a custom-made 2D real-time video analysis software. Agreement between the two computational approaches was assessed using Bland-Altman analysis, Deming regression, and Pearson product-moment correlation. Further, principal component analysis in conjunction with multiple linear regression was used to assess whether individual differences related to the two approaches are due to the waveforms of the acceleration time-series data. Results indicated no mean difference (p > 0.05; d = −0.04) and an extremely large correlation (r = 0.99) between the two approaches. Despite the high agreement, the total error of individual differences was 8.2% (163.0 N). The individual differences can be explained by a multiple linear regression model (R2adj = 0.86) on principal component scores from the principal component analysis of vertical barbell acceleration time-series waveforms. Findings from this study indicate that the individual errors of force measures can be associated with the inverse dynamic approach. This approach uses vertical barbell acceleration data from video analysis that is prone to error. Therefore, it is recommended to use the work-energy approach to compute mean vertical barbell force as this approach did not rely on vertical barbell acceleration.
KW  - Acceleration
KW  - Linear regression analysis
KW  - Velocity
KW  - Principal component analysis
KW  - Kinematics
KW  - Motion
KW  - Scanning electron microscopy
KW  - Computer Software
Y1  - 2021
U6  - https://doi.org/10.1371/journal.pone.0254705
SN  - 1932-6203
VL  - 16
IS  - 7
PB  - PLOS
CY  - San Francisco
ER  -