Sprinting analysis of elite soccer players during European Champions League and UEFA Cup matches

Game interruptions in elite soccer

The objectives of the study were to analyse game interruptions of league soccer in detail and the tactical use of game interruptions. Sixteen matches of a German first league soccer team were observed. An observational system was designed to assess interruption types, score, duration of interruption, location of interruption, time of interruption and number of occurrences. Results showed that there is an average of 108 interruptions per match. Throw-ins (40) and free kicks (33) were most frequent. Goal kicks (17), corner kicks (10), substitutions (4), and kick offs (3) occurred less often. Drop balls, penalties, and injuries occurred least often. For 38% of the total match time observed, matches were halted. The mean duration of running and interrupted match parts were 32.1 s and 18.7 s, respectively. The analysis showed significant differences concerning the influence of the location of interruption, score, and time of interruption on the duration of different interruption types (P < 0.05). The results of the study showed the tactical use of game interruptions during league soccer matches, e.g. goal kicks of the leading team take longer towards the end of the match. Examining game interruptions has turned out to be a valuable source of information adding to our knowledge of soccer. We have shown evidence that the durations of many interruptions serve tactical purposes, a well-known hypothesis in practice.

Local positioning systems in (game) sports

Position data of players and athletes are widely used in sports performance analysis for measuring the amounts of physical activities as well as for tactical assessments in game sports. However, positioning sensing systems are applied in sports as tools to gain objective information of sports behavior rather than as components of intelligent spaces (IS). The paper outlines the idea of IS for the sports context with special focus to game sports and how intelligent sports feedback systems can benefit from IS. Henceforth, the most common location sensing techniques used in sports and their practical application are reviewed, as location is among the most important enabling techniques for IS. Furthermore, the article exemplifies the idea of IS in sports on two applications.

Iliopsoas and gluteal muscles are asymmetric in tennis players but not in soccer players

PURPOSE

To determine the volume and degree of asymmetry of iliopsoas (IL) and gluteal muscles (GL) in tennis and soccer players.

METHODS

IL and GL volumes were determined using magnetic resonance imaging (MRI) in male professional tennis (TP) and soccer players (SP), and in non-active control subjects (CG) (n = 8, 15 and 6, respectively).

RESULTS

The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, P<0.05) and SP (32 and 35%, respectively, P<0.05). In TP the asymmetric hypertrophy of IL (13% greater volume in the non-dominant than in the dominant IL, P<0.01) reversed the side-to-side relationship observed in CG (4% greater volume in the dominant than in the contralateral IL, P<0.01), whilst soccer players had similar volumes in both sides (P = 0.87). The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = -0.97, P<0.001), SP (r = -0.85, P<0.01) and CG (r = -0.76, P<0.05). The slope of the relationship was lower in SP due to a greater hypertrophy of the proximal segments of the dominant IL. Soccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively). GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (P<0.05), whilst TP and CG had similar dominant GL volumes (P = 0.14).

CONCLUSIONS

Tennis elicits an asymmetric hypertrophy of IL and reverses the normal dominant-to-non-dominant balance observed in non-active controls, while soccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury.