Ground reaction force data in functional ankle instability during two cutting movements.

Sport Biomechanics Laboratory, Department of Sports Medicine and Biology of Exercise, Faculty of Physical Education and Sports Science, University of Athens, Greece.
Clinical Biomechanics (Impact Factor: 1.88). 06/2006; 21(4):405-11. DOI: 10.1016/j.clinbiomech.2005.11.010
Source: PubMed

ABSTRACT Functional instability of the ankle joint may interfere with proper execution of quick cutting movements in sports. Previous studies have provided information regarding the ground reaction force characteristics in such movements in healthy players but no research was found in players with ankle instability. The purpose of this study was to evaluate and compare ground reaction forces in functionally unstable ankles with healthy ones during two cutting movements, the v-cut and the defensive shuffle.
Fifteen male basketball players with self reported unilateral functional instability and 17 matched controls, performed three v-cuts and three defensive shuffles on two synchronised force platforms. Both joints were tested and ground reaction forces analysed by an one-way ANOVA for independent groups to test differences between groups, and paired t-test to examine differences within affected players.
Unstable ankles, demonstrated significantly greater first vertical force peak, than contralateral unaffected joints (P < or = 0.05) and lower relative time to peak than controls (P< or = 0.05), during v-cut movement. No significant differences were seen in variables between groups during lateral shuffling.
Unstable ankles demonstrated altered patterns of ground reaction forces, with a rapid onset of high vertical force during the first millisecond post-impact, while the medial component was unchanged. Although the increased vertical forces are considered predisposing factors to repeated injury, this finding is likely a neuromuscular response making the ankle joint more stable avoiding excessive inversion forces.

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    • "soccer, rugby, and Australian football), impact forces can be caused by the collision of the foot with the ground (Nigg & Liu, 1999). The measurement and analysis of foot-strike impact forces has traditionally been performed in laboratory-based settings, using immobile and expensive devices, such as force plates (Besier et al., 2001; Cowley et al., 2006; Dayakidis & Boudolos, 2006). This situation may be of limited value as it is difficult to replicate in-field environmental conditions in a laboratory setting (Wixted & Billing, 2010; Zheng et al., 2008), which may result in an inadequate understanding of the field-based demands imposed on athletes. "
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    Sports Biomechanics 11/2013; 12(4):403-12. DOI:10.1080/14763141.2013.811284 · 0.87 Impact Factor
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    • "In contrast, the popular perception of linear-speed as an exclusively forward-running manifestation does not take into account other sport and occupational activities that comprise some specific movement patterns that are frequently performed with maximal intensity and on a straight line course, but not throughout forward-running. For example, there are other bipedal sport-specific locomotions such as backward running in soccer, or the lateral shuffle in basketball and handball (Mohr et al., 2003; Dayakidis and Boudolos, 2006). "
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    • "The proven relevant and candidate parameters all concern this stabilization phase, and it seems that anteroposterior indices perform better than similar indices in mediolateral direction. The 'sideways' test concerns a great diversity of test instructions: jump (Brown et al., 2010) and hop (Liu et al., 2012) landings from medial and lateral direction, a hop-on-hop-off movement in mediolateral direction (Delahunt et al., 2007), a v-cut and a lateral shuffle (Dayakidis and Boudolos, 2006). Only the stability indices have been used in more than one study (see Table 7), and none of these parameters appears to be sensitive to neuromusculoskeletal impairments. "
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