Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 5

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  Biomechanics
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Biomechanical Responds of Instep Kick between Different Positions in Professional Soccer Players

100%
Khorasani M., Osman N., Yusof A.
Journal of Human Kinetics
|
2009
|
vol. 22
21-27
EN
The purpose of this study was to investigate some selected biomechanical characteristics of lower extremity between professional soccer defenders, midfielders and strikers. The kicking motions of dominant legs were captured from fifteen Olympic professional soccer players; (height: 181.93 ± 7.03 cm; mass: 70.73 ± 10.85 kg; age: 20.8 ± 0.77 years), volunteered to participate in this study, using four digital video cameras. There were significant differences between midfielders and defenders in (1) lower leg angular velocity (p ≤ 0.001), (2) thigh angular velocity (p ≤ 0.001), (3) lower leg net moment (p ≤ 0.001), (4) thigh net moment (p ≤ 0.001), and (5) ball velocity (p ≤ 0.012). There were significant differences between midfielders and strikers in lower leg net moment (p ≤ 0.001). There were significant differences between strikers and defenders in; (1) lower leg angular velocity (p ≤ 0.001), (2) thigh angular velocity (p ≤ 0.001), (3) lower leg net moment (p ≤ 0.001), (4) thigh net moment (p ≤ 0.001), and (5) ball velocity (p ≤ 0.024). In conclusion, midfielders can perform soccer instep kicking strongly and faster than defenders and there is, however, no significant difference between midfielders and strikers, but midfielders' ball velocity is higher than strikers' ball velocity.
2
Publication available in full text mode
Content available

MODELLING MUSCLE FORCE DISTRIBUTIONS DURING THE FRONT AND BACK SQUAT IN TRAINED LIFTERS

100%
Sinclair J., Atkins S., Hayley V., Richards J. D.
Central European Journal of Sport Sciences and Medicine
|
2016
|
vol. 14
|
issue 2
13 - 20
EN
The barbell squat is a fundamental strength and conditioning exercise, with two principal variants; back and front. Whilst previous studies have examined the mechanical differences of the front and back squat, there is no information comparing the distributions of muscle forces between these variants. This study aimed to compare estimated forces developed by the primary skeletal muscles used in the front and back squat. Twenty-five male participants were recruited with 6.24 ±2.21 years of experience in squat lifting and 1 repetition maximum values of 127.5 ±18.8 and 90.6 ±14.4 kg for the back and front squat lifts. Participants completed both back and front squats at 70% of their front squat 1 repetition maximum. Muscle forces were determined during dynamic situations using motion capture data, in addition to sagittal plane kinematics. Differences between squat conditions were examined using a multivariate analysis of variance. The kinematic analysis showed that the back squat was associated with significantly (p < 0.05) greater flexion of the trunk. Examination of muscles forces indicated that erector spinae forces were also significantly (p < 0.05) larger in the back squat. No significant differences were identified for skeletal muscle forces elsewhere (p > 0.05). Our results indicate that neither the front nor back squat provides any marked difference in muscle force production, aside from that isolated to the lower back. These findings lead the conclusion that neither the front nor back squat conditions confer any additional benefits over the other in terms of the skeletal muscle force output.
3
Content available remote

New Regression Models to Evaluate the Relationship between Biomechanics of Gymnastic Vault and Initial Vault Difficulty Values

100%
Atiković A.
Journal of Human Kinetics
|
2012
|
vol. 35
|
issue 1
119-126
EN
The main objective of this paper was to determine the relationship between biomechanical parameters of vault flights with respect to new models of initial vault difficulty values in men’s artistic gymnastic. The study sample included vaults (n=64) and models (n=5) from the 2009 Code of Points (CoP) of the Federation International of Gymnastics (FIG). The dependent variable included all difficulty values ranging from 2-7.2 points, while the sample of independent variables included twelve biomechanical parameters. After implementing the regression analysis, it could be established that the best model derived only the second flight phase with 95% of explained variance.
4
Content available remote

The Backstroke Swimming Start: State of the Art

88%
de Jesus K., de Jesus K., Fernandes R. J., Vilas-Boas J. P., Sanders R.
Journal of Human Kinetics
|
2014
|
vol. 42
|
issue 1
27-40
EN
As sprint swimming events can be decided by margins as small as .01 s, thus, an effective start is essential. This study reviews and discusses the ‘state of the art’ literature regarding backstroke start biomechanics from 23 documents. These included two swimming specific publications, eight peer-reviewed journal articles, three from the Biomechanics and Medicine in Swimming Congress series, eight from the International Society of Biomechanics in Sports Conference Proceedings, one from a Biomechanics Congress and one academic (PhD) thesis. The studies had diverse aims, including swimmers’ proficiency levels and data collection settings. There was no single consensus for defining phase descriptions; and kinematics, kinetics and EMG approaches were implemented in laboratory settings. However, researchers face great challenges in improving methods of quantifying valid, reliable and accurate data between laboratory and competition conditions. For example, starting time was defined from the starting signal to distances as disparate as ~5 m to 22.86 m in several studies. Due to recent rule changes, some of the research outcomes now refer to obsolete backstroke start techniques, and only a few studies considered the actual international rules. This literature review indicated that further research is required, in both laboratory and competition settings focusing on the combined influences of the current rules and block configuration on backstroke starting performances
5
Content available remote

Kinematic gait analysis of a young man after amputation of the toes

88%
Forczek W., Ruchlewicz T., Gawęda A.
Biomedical Human Kinetics
|
2014
|
vol. 6
|
issue 1
EN
Study aim: the foot is recognised as a “functional unit” with two important aims: to support body weight and to serve as a lever to propel the body forward. When it is impaired, the locomotor pattern has to adapt to compensate for the dysfunction. The purpose of this study was to investigate gait kinematics of a man after bilateral partial amputation of the toes. Material and methods: the subject of the study was a young man aged 30 years (body height and mass: 186 cm, 82 kg) who suffered a frostbite injury in the feet while climbing in the severe mountain conditions. After a few months of treatment, the necessary amputation occurred. Three-dimensional lower limb kinematics was collected from motion capture system (Vicon 250) and Golem marker set-up using 5 video-based cameras with infrared strobes. The subject performed over-ground walking at self-selected speed, first barefoot, then wearing athletic shoes. Results: the patient’s results are the mean values of sixteen full gait cycles. The spatiotemporal parameters were lower during gait without shoes. In terms of the angular changes of the lower limb joints in sagittal plane, the analysis revealed similar functional patterns and typical trends in both recorded conditions. The differences, however, occurred in their amplitude. A larger range of motion was generally noted in shod conditions. The higher the joint was, the smaller the differences were. Conclusion: changes in gait due to the forefoot dysfunction may be stabilizing adaptations related to fear of falling. Footwear provided more stable conditions.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.