| 1. |
- Bagehorn, T., et al.
(author)
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Effect of increased shoe longitudinal bending stiffness on ankle and foot biomechanics in jump-cut movements of low and high degrees
- 2024
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In: Footwear Science. - : Informa UK Limited. - 1942-4280 .- 1942-4299. ; 16:2, s. 135-146
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Journal article (peer-reviewed)abstract
- Lateral ankle sprains are the most common injuries in indoor and court sports, with ankle inversion being a primary injury driver. Stabilising the ankle during multidirectional changes is crucial for injury prevention. Conversely, increased shoe stiffness has been hypothesised to influence the magnitude of ankle inversion and may raise the risk for ankle injuries. Therefore, the purpose of this study was to investigate the influence of shoe longitudinal bending stiffness on ankle biomechanics during indoor and court sport-specific cutting movements. Biomechanical data from 19 participants were collected using a motion capture system and force plate. A jump-cut protocol with two different cutting directions after landing was performed in indoor shoes with and without carbon plate inserts of varying stiffness. Ankle kinematics and kinetics were analysed with statistical parametric mapping and repeated measures analysis of variance. A significant increase in ankle inversion during the 180° cut and a reduction in forefoot inversion (foot torsion) for stiffer footwear conditions during both the 45° and 180° cut were observed. While dorsiflexion moments differed during the last 10% of ground contact, ankle inversion moments did not significantly diverge between shoe conditions. Furthermore, a noteworthy correlation between footwear longitudinal bending stiffness and torsional stiffness was identified. In conclusion, increased bending stiffness significantly affected ankle and foot kinematics. The ankle compensated for restricted mobility and higher demands during high-degree jump-cuts, while foot torsion played a more prominent role in low-degree cuts. The heightened ankle inversion during high-degree cuts may induce an elevated risk for lateral ankle sprains. Further longitudinal studies are necessary to comprehensively understand injury incidence and the role of shoe stiffness in injury prevention.
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| 2. |
- Bentham, James, et al.
(author)
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A century of trends in adult human height
- 2016
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In: eLIFE. - 2050-084X. ; 5
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Journal article (peer-reviewed)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.522.7) and 16.5 cm (13.319.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 3. |
- Bentham, James, et al.
(author)
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A century of trends in adult human height
- 2016
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In: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 5
-
Journal article (peer-reviewed)abstract
- Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3– 19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8– 144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries.
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| 4. |
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| 5. |
- Ferdinands, R. E. D., et al.
(author)
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A new taxonomic system for the sub-classification of cricket bowling actions
- 2014
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In: Sports Technology. - : Informa UK Limited. - 1934-6182 .- 1934-6190. ; 7:1-2, s. 26-38
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Journal article (peer-reviewed)abstract
- The mixed bowling action is associated with injuries in the lumbar spine and has been shown to have no performance benefits over other bowling actions. The purpose of this study was to assess the mixed bowling action with reference to a more comprehensive classification system to facilitate the development of more targeted bowling action remediation programs. A total of 70 fast bowlers were tested using a three-dimensional motion analysis system (240 Hz). Kinematic data of the shoulders and pelvis were analysed with respect to a modified set of angle threshold criteria to classify bowling actions. It was found that the mixed action bowlers (49% of the sample) could be sub-divided into seven distinct mixed action types. The most common of these types were the mixed front-on bowlers with respect to shoulder counter-rotation (19%) and the mixed front-on bowlers with respect to both pelvis-shoulder separation angle and shoulder counter-rotation (14%). It is envisaged that a more comprehensive classification of bowling actions may assist researchers in the future to define mixed action types with a tighter domain of variables that are more indicative of lumbar injury risk. © 2014 Taylor & Francis.
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| 6. |
- Ferdinands, R. E. D., et al.
(author)
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A twenty-segment kinematics and kinetics model for analysing golf swing mechanics
- 2013
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In: Sports Technology. - : Informa UK Limited. - 1934-6190 .- 1934-6182. ; 6:4, s. 184-201
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Journal article (peer-reviewed)abstract
- The golf swing is a complex, multi-planar, three-dimensional (3D) motion sequence performed at very high speeds. These properties make biomechanical analysis of the golf swing difficult. Hence, the aim of this study was to develop a computer model of the golf swing capable of calculating a diverse range of 3D kinematics and kinetics values based on motion analysis data collected in the laboratory. Five golfers performed six swings in the field of view of eight Falcon High Speed Resolution cameras (240 Hz), which captured the movements of 56 markers placed on the golfers and their clubs, resulting in marker trajectories that were processed into linear xyz-coordinates using the Eva Motion Analysis system. To perform the kinematics and kinetics calculations, a 20-segment rigid body model of the human body was designed in the Mechanical Systems Pack, connecting the segments by a selection of linear and spherical constraints, resulting in a system of segments with 58 degrees of freedom, with the constraint equations of motion calculated by the Newton-Lagrangian iteration method. The model allowed for the derivation of segmental sequencing, separation angles, segmental planes of motion, segmental velocity contributions, joint torques and muscle powers. The preliminary data suggest that such an integrated kinematics and kinetics analysis is necessary to understand the mechanical complexity of golf swing. Even with the small sample size analysed in this study, some interesting trends were found, such as certain violations of the classical proximal-to-distal sequencing scheme, differing swing plane and club head trajectories in the backswing and downswing phases, minimal hip angular velocity contribution to the ball at impact, concentric and eccentric muscle powers in the downswing phase, and increased lumbar loading factors from the mid-downswing phase to ball impact. © 2014 Taylor & Francis.
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| 7. |
- Jensby Nedergaard, Niels, et al.
(author)
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The effect of light reflections from the snow on kinematic data collected using stereo-photogrammetry with passive markers
- 2014
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In: Sports Engineering. - : Springer Science and Business Media LLC. - 1369-7072 .- 1460-2687. ; 17:2, s. 97-102
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Journal article (peer-reviewed)abstract
- This study aimed to compare kinematic data collected during ski-cross starts outdoors on snow in daylight (high albedo) to similar data collected indoors with infiltrating sunlight but without light reflections from the snow (low albedo) using a video-based motion capture system with the active filtering function enabled. A 12-camera 3D motion capture system (Qualisys AB, Sweden) was used to measure test objects and eight skiers performing a ski-cross start on a slope outdoors and on a wooden start ramp indoors. The average residuals and standard deviations of the length of the calibration wand calculated indoors and outdoors by the calibration software were compared using descriptive statistics. Static and moving fixed length measures and thigh length measures were compared using Bland-Altman plots. Calibration residuals were slightly increased outdoors (1.77 mm) compared to indoors (1.54 mm), while wand length varied by 3.63 and 1.51 mm, respectively. Fixed static lengths differed by -8.65 ± 4.94 mm (shorter indoors), whereas fixed moving lengths differed by 0.85 ± 1.05 mm (longer indoors). A randomly chosen marker pair on one segment (Thigh) showed a mean difference of 1.19 ± 22.05 mm (longer indoors). It is concluded that 3D motion capture outdoors on snow in daylight is feasible, provides kinematic data comparable to indoors, and could be used to research biomechanics in snow sports.
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| 8. |
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| 9. |
- Kersting, Uwe G, et al.
(author)
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Kinematic and kinetic energy analysis of segmental sequencing in cricket fast bowling
- 2013
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In: Sports Technology. - : Routledge. - 1934-6182 .- 1934-6190. ; 6:1, s. 10-21
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Journal article (peer-reviewed)abstract
- Although there have been many studies to quantify the segmental sequencing in other sports, there has been little such research applied to cricket bowling. In this study, 34 fast bowlers (22.3 ± 3.7 years) of premier grade level and above were tested using 3D motion analysis, their balls speed ranging from 27.0 to 35.6 m s− 1. One-way repeated measures ANOVA was used to test for within-participant differences in segmental sequencing based on the timings of maximum segmental angular velocities and kinetic energies, the data showing that bowlers exhibited a general order of proximal-to-distal sequencing. Bivariate Pearson's product-movement correlation coefficients were calculated to assess the relationships between kinematic variables and ball release speed, yielding a set of variables for entry into a stepwise multiple regression model. The multiple regression model with the sequential timing variables of thoracic linear kinetic energy (KE), upper-arm circumduction velocity and forearm rotation KE, as well as the pelvic–shoulder separation acceleration accounted for 55% of the variability in ball speed (R 2 = 0.55, adjusted R 2 = 0.49, F(4, 29) = 8.86, p < 0.001). This study showed that both the magnitude and the timing of segmental activation are important to generate ball speed in fast bowling.
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| 10. |
- Kurpiers, Nicolas, et al.
(author)
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Perspectives for Comprehensive Biomechanical Analyses in Mogul Skiing
- 2009
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In: Research in Sports Medicine. - London : Taylor & Francis. - 1543-8627 .- 1543-8635. ; 17:4, s. 231-244
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Journal article (peer-reviewed)abstract
- The purpose of this study was to examine the effects of using aforce measurement device on riding technique in mogul skiing. Amock-up version of such a device was positioned between ski bootand binding. Data on three-dimensional kinematics and perceptionwere collected for eight subjects skiing down a mogul course.Parameters analysed were knee angle, side and forward lean ofthe trunk and hip, and the path of the body’s centre of mass. A perceptionquestionnaire was used on selective aspects to assess theskiers’ perception of the performances. Perception ratings showedno significant detrimental effects. All assessed components showeda trend of improvement from the first to last run, thus suggestingfamiliarisation was achieved. Kinematic analysis revealed that nosignificant alterations occurred. In conclusion, it is intended toutilise a functional force plate similar to the one presented byKiefmann et al. (2006) for future studies in freestyle skiing.
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