Tomasz Marciniak, Ida Wiszomirska and Lidia Ilnicka
Study aim: Assessment of postural stability performed on an unstable stabilometry platform. Comparison of the results obtained by two groups consisting of elderly (OW) (60+ years old) and younger women (YW).Material and methods: Seventy-three female volunteers were divided into two groups: 40 young women (20.2 ± 1.75), and 32 elderly women (68.3 ± 7.43). Participants performed five stability tests on Biodex Balance System SD: three 20-second tries, the Postural Stability Test (PST) and the Fall Risk Test (FRT). Three stability indexes - overall (OSI), anterior-posterior (APSI), and medial-lateral (MLSI) - both with eyes open (EO) and closed (EC) were analyzed. The impact of vision on balance was calculated as EC-EO. Also effect size was calculated and evaluated.Results: All of the parameters differed significantly between groups in favour of YW. The largest difference in significance as well as effect size was noted for FRT, p < 0.001 and 1.86 respectively. Tries measure the impact of vision on balance (EC-EO). The results concerning tries with EC-EO showed the strongest discrimination between groups - OSI p = 0.0088 (relative difference 0.23 ± 0.26) and APSI p = 0.0268 (relative difference 0.17 ± 0.2). YW had a significantly better outcome.Conclusions: YW had better results in all of the parameters taken into consideration, with most of them being significant. This confirms that all of the regressive changes appearing with age influence balance. Lack of visual input (EC) in OW caused significantly worse results in most of the measured parameters, showing that vision is a very important factor for balance maintenance in the elderly.
Study aim: Two thirds of children are not meeting recommended levels of physical activity. A solution to physical inactivity is Comprehensive School Physical Activity Programming (CSPAP). Little is known regarding the impact of a school’s physical activity leader on CSPAP effectiveness. Therefore, this study explored changes in physical activity accumulated during school hours in CSPAP schools being led by the physical education teacher compared to a stand-alone physical activity leader.
It is well known that substrate oxidation rates are increased by exercise. The present study had two main objectives: firstly, to examine the effect of a single exhaustive exercise session on post-exercise substrate oxidation and energy expenditure; and secondly, to determine the differences between athletes and non-athletes.
Material and methods: Eighteen healthy male athletes (mean ± SD age; 19.38 ± 2.26 years, VO2max; 60.57 ± 3.90 ml · kg-1 · min-1, n = 8) and non-athletes (age; 20.30 ± 1.26 years, VO2max; 44.97 ± 5.43 ml · kg-1 ·min-1, n = 10) volunteered to participate in the study. After an overnight fast, subjects performed a single sprint exercise session on a cycle ergometer with individual loads (0.075 kg per body weight) until volitional exhaustion. Energy expenditure (EE) and the substrate oxidation rate were measured at rest and during the post-exercise recovery period using indirect calorimetry. Results: Exhaustive exercise significantly increased post-exercise fat oxidation, energy expenditure and contribution of fat to EE (p < 0.05). Also, it significantly decreased post-exercise carbohydrate (CHO) oxidation and the contribution of CHO to EE (p < 0.05). However, the changes in the substrate oxidation rate and EE after the exercise test were not different between the groups (p > 0.05). Conclusions: The study results suggest that a single short-duration exhaustive exercise session causes a higher fat oxidation rate during recovery than at rest, whereas training status did not affect this situation
The surface EMG signal in the action of dynamic contraction has more movement interference compared to sustained static contractions. In addition, the recruitment and de-recruitment of motor units causes a faster change in the surface EMG signal’s proprieties. Therefore, more complex techniques are required to extract information from the surface EMG signal. The standardized protocol for surface myoelectric signal measurement in table tennis was a case study in this research area. The Autoregressive method based on the Akaike Information Criterion, the Wavelet method based on intensity analysis, and the Hilbert-Huang transform method were used to estimate the muscle fatigue and non-fatigue condition. The result was that the Hilbert-Huang transform method was shown to be more reliable and accurate for studying the biceps brachii muscle in both conditions. However, the Wavelet method based on intensity analysis is more reliable and accurate for the pectoralis major muscle, deltoideus anterior muscle and deltoideus medialis muscle. The results suggest that different time-frequency analysis techniques influence different muscle analyses based on surface EMG signals in fatigue and non-fatigue conditions
Zsolt Csirkés, Károly Bretz, Katalin Jakab and Rita F Földi
Study aim: To investigate the effects of 6-month sensorimotor training on postural control of 5-6-year-old preschool children born with ‘biological risk factors’ (BRF). Material and methods: Sixty-four Hungarian preschoolers participated in this study, and were assigned to an experimental group (n = 17), control group 1 (n = 23) and control group 2 (n = 24). The experimental group (born with BRF) attended a 6-month balance intervention based on Ayres’ therapy, while control group 1 (born with BRF) and control group 2 (born with no BRF) followed the regular preschool schedule. Birth weight, gestational age at birth, Apgar score and other abnormalities during pregnancy and birth were considered to be BRF. A moveable platform (stabilometer) was used to examine the distance of center of pressure movements of all participants prior to the start and after the end of the intervention. The testing procedure was performed with four enjoyable tests in the same sequence (‘Mouse in the hole’, ‘Center’, ‘Christmas tree’, ‘Square painting’). Results: The balance intervention program resulted in significant improvements in postural control of the experimental group. In three of six variables the balance index scores of the intervention group approached the scores of their peers born without BRF, and they even had better performance in three of six variables. Conclusions: Balance training with instability training devices could help children born with BRF attain a higher level of integration through the stimulation of tactile and balancing senses.
So Yeon Kim, Su Jin Park, Ye Eun Lee, Eun Ha Lee, Hwa Yeong Lim, Hwa Yeong Lim and Gyu Yoo
Study aim: The purpose of this study was to confirm the effectiveness of tele-rehabilitation mental practice (TRMP) on balancing performance for patients with hemiplegia. Material and methods: This study included five stroke patients, and all participants were trained to help to recover balancing performance. TRMP was applied for a total of 15 training sessions for 3 weeks, and pre- and post-intervention evaluations were carried out during this study. The Berg Balance Scale was used to confirm the balance ability, the Modified Falls Efficacy Scale to confirm the falls efficacy, and the Wii program to confirm the right and left weight distribution ratio. Results: As a result of this study, we could not confirm a significant difference between pre- and post-intervention balance capacity and fall efficacy. However, weight distribution showed a significant difference after the intervention. Conclusion: TRMP may be applied in novel balance training for stroke patients.
Mohsen Razeghi, Samaneh Ebrahimi, Farzaneh Yazdani and Behdad Tahayori
Study aim: There is a lack of evidence to show the presence or absence of a relationship between foot morphology and changes of the force applied to the knee extensor mechanism. The purpose of this study was to examine whether the type of foot is a determining factor in the force applied to the extensor mechanism during walking. Materials and methods: Twenty female subjects (18-30 years), 10 with neutrally aligned feet and 10 with functional flat foot, participated in this study. Data were collected by employing a three dimensional motion capture system and a force platform, while the subjects were walking at their preferred speed. Knee extensor mechanism force was measured at sub-phases of gait (heel strike and toe-off). Results: A significant interaction was found between groups and sub-phases of gait for all the variables tested. The subjects with flat foot exhibited a significantly higher extensor mechanism force at toe-off compared to the control group (p < 0.05). Conclusion: It can be concluded that subtalar hyper-pronation would increase the force applied to the knee extensor mechanism at toe-off, through increasing the knee sagittal angle, net external flexion moment and extensor mechanism moment arm. Therefore it may increase the possibility of musculoskeletal injuries
Lucas de Lucena Simões e Silva, Matheus Santos de Souza Fernandes, Eline Autran de Lima, Raul Emídio de Lima and Patrícia Muniz Mendes Freire de Moura
Study aim: Was to verify whether the regular practice of physical activity promotes some protective factor against the development of LS in patients infected with hepatitis C virus (HCV). Materials and method: Clinical data were obtained through medical records available at the Pernambuco Liver Institute. Physical activity levels were obtained through the International Physical Activity Questionnaire (IPAQ) short form to classify the patients according to the guidelines of the American College of Sports Medicine (ACSM). Results: The sample consisted of patients of both genders, over 18 years of age, who had positive anti-HCV, HCV-RNA and confirmatory tests for presence or absence of liver steatosis. 126 patients were included in the study. Patients with liver steatosis (G1) were more frequently male (57%) compared to patients without liver steatosis (G2) (p = 0.02). Physical activity analysis showed significant differences for GGT (p = 0.04), HDL (p = 0.04), AF (p = 0.02), viral genotype 3 (p = 0.04) and waist-to-hip ratio (p = 0.01) in anthropometric data. Correlation analysis showed a significant difference for GGT (r = -0.23; p = 0.01) and total bilirubin (BT) (r = -0.22; p = 0.01). Conclusions: Regular practice of physical activity generates a protective factor against the development of LS in patients infected by the hepatitis C virus and it is associated with the maintenance of variables related to hepatic and biochemical damage in patients infected with HCV.
D. L. Carey, K. Ong, R. Whiteley, K. M. Crossley, J. Crow and M. E. Morris
To investigate whether training load monitoring data could be used to predict injuries in elite Australian football players, data were collected from athletes over 3 seasons at an Australian football club. Loads were quantified using GPS devices, accelerometers and player perceived exertion ratings. Absolute and relative training load metrics were calculated for each player each day. Injury prediction models (regularised logistic regression, generalised estimating equations, random forests and support vector machines) were built for non-contact, non-contact time-loss and hamstring specific injuries using the first two seasons of data. Injury predictions were then generated for the third season and evaluated using the area under the receiver operator characteristic (AUC). Predictive performance was only marginally better than chance for models of non-contact and non-contact time-loss injuries (AUC<0.65). The best performing model was a multivariate logistic regression for hamstring injuries (best AUC=0.76). Injury prediction models built using training load data from a single club showed poor ability to predict injuries when tested on previously unseen data, suggesting limited application as a daily decision tool for practitioners. Focusing the modelling approach on specific injury types and increasing the amount of training observations may improve predictive models for injury prevention
Recently there has been an interest in developing tennis scoring systems that involve playing a fewer number of points on average. In devising such ‘shorter’ tennis scoring systems, it would be ideal for them to also have the following four characteristics: A smaller standard deviation of duration, a similar value for the probability that the better player wins, an increased efficiency, and a greater average excitement per point played. Thus, in total there are five considerations when devising such new scoring systems. Quite often in this type of study a scoring system that is ‘better’ with regard to one of these characteristics is ‘worse’ with regard to another (or others). In this paper we outline some new tennis scoring systems that have improvements in all (or almost all) of these five characteristics. We identify 3 or 4 different game structures that could be useful for tournaments. A common thread in the approach taken is the elimination of unimportant and unexciting points within the game structure. The choice of which is the most appropriate new format for a particular tournament would depend amongst other things on the planned reduction in the expected set duration