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Ljubljana, Slovenia

Sarabon N.,University of Primorska | Sarabon N.,S2P Ltd | Panjan A.,S2P Ltd | Latash M.,Pennsylvania State University
Gait and Posture | Year: 2013

The effects of healthy aging on postural sway and its rambling and trembling components were studied. Young and elderly subjects stood quietly for 1. min in different postures, and with eyes open and closed. We found that age-related changes in postural sway and its components were similar to those observed in young participants in challenging conditions. These changes may therefore be viewed as secondary to the increased subjective perception of the complexity of postural tasks. Contrary to our expectations, stronger effects of age were seen in characteristics of rambling, not trembling. The commonly accepted hypothesis that older persons rely on vision more was not supported by this study: we found no significant interaction effects of age and vision on any of the sway characteristics. It was concluded that the reported higher reliance on vision in older persons may be task-specific. The results are compatible with the ideas that much of the age-related changes in postural sway emerge at the level of exploring the limits of stability and using the drift-and-act strategy. Our results suggest that the dominant view on rambling and trembling as reflecting supraspinal and peripheral mechanisms, respectively, may be too simplistic. © 2013 Elsevier B.V.

Filipcic A.,University of Ljubljana | Panjan A.,S2P Ltd | Reid M.,Sport Science and Medicine Unit | Crespo M.,International Tennis Federation | And 2 more authors.
Journal of Sports Science and Medicine | Year: 2013

This article discusses the relationship between success of professional male tennis players according to the country and world region from which they originate and the professional tournament structure in men's tennis in that world region and country. The success of a country or world region was defined by the number of players in the top 300 ATP rankings and was calculated for seven time periods between 1975 and 2008. The results showed the correlations between the total number of top 300 ranked players, the total number of tournaments, and the annual tournament prize money of the specific country. The correlations were nearly perfect in the 1975-1990 period (r = 0.93- 0.95; p < 0.01) but only high in the 2005-2008 period (r = 0.60- 0.64; p < 0.01), suggesting that the association between the number of top 300 ranked tennis players and professional tournaments, while still significant, is in decline. These data should inform the policy and investment decisions of regional and national federations, particularly as they relate to domestic professional tennis tournament structures and to explore opportunities to include professional tournaments of neighbour countries in their player's development programs. © Journal of Sports Science and Medicine (2013).

Fonda B.,S2P Ltd | Panjan A.,S2P Ltd | Markovic G.,S2P Ltd | Markovic G.,University of Zagreb | And 2 more authors.
Journal of Electromyography and Kinesiology | Year: 2011

The main aim of this project was to study muscle activity patterns during steep uphill cycling (UC) (i.e., with a gradient of 20%) with (1) normal saddle geometry and (2) with adjusted saddle position ASP (i.e., moving the saddle forward and changing the tilt of the saddle by 20%). Based on our preliminary case study, we hypothesized that: (1) during 20% UC muscle activity patterns would be different from those of level cycling (LC) and (2) during 20% UC with ASP muscle activity patterns would resemble those of LC. Twelve trained male cyclists were tested on an electromagnetically braked cycle ergometer under three conditions with the same work rate (80% of maximal power output) and cadence (90. rpm): level (LC), 20% UC and 20% UC with ASP. Electromyographic signals were acquired from m. tibialis anterior (TA), m. soleus (SO), m. gastrocnemius (GC), m. vastus lateralis (VL), m. vastus medialis (VM), m. rectus femoris (RF), m. biceps femoris (BF) and m. gluteus maximus (GM). Compared to LC, 20% UC significantly modified both the timing and the intensity of activity of the selected muscles, while muscles that cross the hip joint were the most affected (RF later onset, earlier offset, shorter range of activity and decrease in peak amplitude of 34%; BF longer range of activity; GM increase in peak amplitude of 44%). These changes in EMG patterns during 20% UC were successfully counteracted by the use of ASP and it was interesting to observe that the use of ASP during 20% UC was perceived positively by all cyclists regarding both comfort and performance. These results could have a practical relevance in terms of improving performance during UC, together with reducing discomfort. © 2011 Elsevier Ltd.

Babic J.,Jozef Stefan Institute | Petric T.,Jozef Stefan Institute | Peternel L.,Jozef Stefan Institute | Sarabon N.,University of Primorska | Sarabon N.,S2P Ltd
Gait and Posture | Year: 2014

There are many everyday situations in which a supportive hand contact is required for an individual to counteract various postural perturbations. By emulating situations when balance of an individual is challenged, we examined functional role of supportive hand contact at different locations where balance of an individual was perturbed by translational perturbations of the support surface. We examined the effects of handle location, perturbation direction and perturbation intensity on the postural control and the forces generated in the handle.There were significantly larger centre-of-pressure (CoP) displacements for perturbations in posterior direction than for perturbations in anterior direction. Besides, the perturbation intensity significantly affected the peak CoP displacement in both perturbation directions. However, the position of the handle had no effects on the peak CoP displacement. On the contrary, there were significant effects of perturbation direction, perturbation intensity and handle position on the maximal force in the handle. The effect of the handle position was significant for the perturbations in posterior direction where the lowest maximal forces were recorded in the handle located at the shoulder height. They were comparable to the forces in the handle at eye height and significantly lower than the forces in the handle located either lower or further away from the shoulder.In summary, our results indicate that although the location of a supportive hand contact has no effect on the peak CoP displacement of healthy individuals, it affects the forces that an individual needs to exert on the handle in order to counteract support perturbations. © 2014 Elsevier B.V.

Voglar M.,University of Primorska | Sarabon N.,University of Primorska | Sarabon N.,S2P Ltd
Journal of Sports Science and Medicine | Year: 2014

Therapeutic Kinesio Taping method is used for treatment of various musculo-skeletal conditions. Kinesio Taping might have some small clinically important beneficial effects on range of motion and strength but findings about the effects on proprioception and muscle activation are inconsistent. The aim of this study was to test if Kinesio Taping influences anticipatory postural adjustments and postural reflex reactions. To test the hypothesis twelve healthy young participants were recruited in randomized, participants blinded, placebo controlled cross-over study. In the experimental condition the tape was applied over the paravertebral muscles and in placebo condition sham application of the tape was done transversally over the lumbar region. Timing of anticipatory postural adjustments to fast voluntary arms movement and postural reflex reactions to sudden loading over the hands were measured by means of superficial electromyography before and one hour after each tape application. Results showed no significant differences between Kinesio Taping and placebo taping conditions for any of the analyzed muscles in anticipatory postural adaptations (F1,11 < 0.23, p > 0.64, η2 < 0.04) or postural reflex reactions (F1,11 < 4.16, p > 0.07, η2 < 0.49). Anticipatory postural adjustments of erector spinae and multifidus muscles were initiated significantly earlier after application of taping (regardless of technique) compared to pre-taping (F1,11 = 5.02, p = 0.046, η2 = 0.31 and F1,11 = 6.18, p = 0.030, η2 = 0.36 for erector spinae and multifidus, respectively). Taping application over lumbar region has potential beneficial effects on timing of anticipatory postural adjustments regardless of application technique but no effect on postural reflex reactions in young pain free participants. Further research in patients with low back pain would be encouraged. © Journal of Sports Science and Medicine.

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