Effects of Minimalist Footwear and Foot Strike Pattern on Plantar Pressure during a Prolonged Running

The use of minimalist shoes (MS) in running involves changes in running mechanics compared to conventional shoes (CS), but there is still little research analysing the effects of this footwear on plantar pressure, which could help to understand some risk injury factors. Moreover, there are no studies examining the effects of a prolonged running and foot strike patterns on baropodometric variables in MS. Therefore, the aim of this study was to analyse the changes produced using MS on plantar pressure during a prolonged running, as well as its interaction with the time and foot strike pattern. Twenty-one experienced minimalist runners (age 38 ± 10 years, MS running experience 2 ± 1 years) ran with MS and CS for 30 min at 80% of their maximal aerobic speed, and mean pressure, peak pressure, contact time, centre of pressure velocity, relative force and contact area were analysed using a pressure platform. Foot strike pattern and time were also considered as factors. The multivariable linear regression mixed models showed that the use of MS induced, at the end of a prolonged running, higher peak pressure (p = 0.008), lower contact time (p = 0.004) and lower contact area (p < 0.001) than using CS. Also, runners with forefoot strike pattern using MS, compared to midfoot and rearfoot patterns, showed higher mean and peak pressure (p < 0.001) and lower contact time and area (p < 0.05). These results should be considered when planning training for runners using MS, as higher peak pressure values when using this type of footwear could be a risk factor for the development of some foot injuries.

The Impact of Rope Jump Exercise Training on Hemolytic Anemia Parameters in Obese Adolescent Boys

Background: One of the theories about hemolytic anemia concerns foot-strike on the ground. Rope jump exercise training (RJET) is performed with high foot-strike repetitions on the ground. Objectives: This paper aimed to study the possible effect of RJET on hematological parameters involved in hemolysis. Methods: Twenty obese adolescent boys with a mean age of 13.40 ± 1.09 years were allocated into two equal groups of control and RJET (n = 10 each). The RJET group performed simple rope jumping for eight weeks (three days a week). Blood samples were collected before and after the protocol. Independent t-test and Mann-Whitney U test were used for data analysis. Results: Our findings showed no significant inter-group differences for erythrocyte, platelet, and leukocyte parameters. However, given the effect of time, a significant reduction was observed in monocyte count in the RJET group. In contrast, eosinophil count significantly increased after RJET. Conclusions: According to the results, foot striking induced by RJET had no adverse effect on hemolytic anemia in obese adolescent boys.

Foot Strike Patterns During Overground Distance Running: A Systematic Review and Meta-Analysis

Background Investigations of foot strike patterns during overground distance running have foci on prevalence, performance and change in foot strike pattern with increased distance. To date, synthesised analyses of these findings are scarce. Objective The key objectives of this review were to quantify the prevalence of foot strike patterns, assess the impact of increased running distance on foot strike pattern change and investigate the potential impact of foot strike pattern on performance. Methods Relevant peer-reviewed literature was obtained by searching EBSCOhost CINAHL, Ovid Medline, EMBASE and SPORTDiscus (inception-2021) for studies investigating foot strike patterns in overground distance running settings (> 10 km). Random effects meta-analyses of prevalence data were performed where possible. Results The initial search identified 2210 unique articles. After removal of duplicates and excluded articles, 12 articles were included in the review. Meta-analysis of prevalence data revealed that 79% of long-distance overground runners rearfoot strike early, with prevalence rising to 86% with increased distance. In total, 11% of runners changed foot strike pattern with increased distance and of those, the vast majority (84%) do so in one direction, being non-rearfoot strike to rearfoot strike. Analysis of the relationship between foot strike pattern and performance revealed that 5 studies reported a performance benefit to non-rearfoot strike, 1 study reported a performance benefit to non-rearfoot strike in women but not men, 4 studies reported no benefit to non-rearfoot strike or rearfoot strike, and no studies reported a performance benefit of rearfoot strike over non-rearfoot strike. Conclusion Most overground distance runners rearfoot strike early, and the prevalence of this pattern increases with distance. Of those that do change foot strike pattern, the majority transition from non-rearfoot to rearfoot. The current literature provides inconclusive evidence of a competitive advantage being associated with long-distance runners who use a non-rearfoot strike pattern in favour of a rearfoot strike pattern.

CONTENT ANALYSIS OF SOME DOCTORAL THESIS STUDIES CARRIED OUT IN TURKEY ON THE BRANCH OF TAEKWONDO IN THE FIELD OF SPORTS SCIENCES

<p>Taekwondo is an old martial art with a Korean origin that is performed with hands and feet, where several combined techniques are used together, and nerve-muscle use levels are high (Mark, 1984; Kim et al., 2011). The history of taekwondo may be traced back to centuries ago. Initially, this branch used to be taught for the person to defend themselves. Afterwards, throughout the centuries, it has been spread around the world as an artistic form. In addition to having an artistic form, the branch of taekwondo also requires high competitive strength. Taekwondo is a competitive sport that requires the displacement of the body parts of the opponent. As words, ‘tae’ means foot strike, ‘kwon’ means hand strike, and ‘do’ means philosophy (Kazemi et al., 2006). Taekwondo competitions are divided into two categories as sparring and poomsae. Sparring is performed against an opponent, while poomsae (imaginary sparring) is a branch where a single person performs. Taekwondo that is known as a demonstration sport showed itself for the first time in the 1988 Seoul and 1992 Barcelona Olympics. Its inclusion in official competitions occurred in the 2000 Sydney Olympic Games (Kazemi et al., 2004; Gupta, 2011). Taekwondo as an Olympic sport is a branch performed by 75-120 million individuals in more than 140 countries (Razi, 2016). Innovations made in equipment in time, changes in rules, safety measures, organization of competitions, and its prominent media- and education-related aspects have increasingly raised the interest in this branch and helped it gain its popularity today. With the increase in the popularity of the branch and the prominence it has gained in the Olympics, World Taekwondo has recently made some changes in the rules. Some changes may be listed as changes in the scoring system (increase in the point score of techniques applied on the head region), smaller game dimensions, enaction of the 10-sec rule and changes in penalty points (Moenig, 2015). Competitions are held in the form of 3 rounds of 1.5 minutes each for the Juniors and Teens categories and 3 rounds of 2 minutes each for the Youths and Adults categories, with 1 minute of rest between the rounds (Birrer, 1996; Toskovic et al. 2004; Heller ve ark., 1998). Competitions consist of various techniques applied on the head and torso regions. These techniques may be applied in the form of attack, counterattack and combined techniques. Athletes are scored based on the region on which they apply the techniques and the degree of difficulty. For athletes to receive points, they need to have multiple physical qualities. For competitive performance, taekwondo requires various factors including physical (Heller ve ark., 1998; Gao, 2001; Melhim, 2001; Ball et al.,2011; Estevan et al., 2011), psychological (de Prado, 2012), technical (Bridge et al., 2011; Cular et al., 2011) and tactical (Falcó et al., 2009; González et al., 2011) factors. This is why taekwondo training has been structured in a way to target these specific performance mediators (Heller et al., 1998; Gao, 2001). From this perspective, the purpose of taekwondo training is to prepare athletes in terms of both their physical activities and meeting of the physiological demands of competition (Marković et al., 2005; Pieter, 1991; Casoline et al., 2012). As strikes are important in taekwondo, athletes need to have explosive leg strength, aerobic resilience, balance and flexibility (Heller et al., 1998; Marković et al., 2005). Taekwondo athletes must have the capacity to rapidly produce muscle strength through kicks, because 80% of taekwondo skills are related to kicking (Shirley, 1992). Although these characteristics are not the only determinants of performance, they are among helpful pieces of information for trainers. There are studies in the literature on the physical and physiological characteristics of athletes. Nevertheless, it is important to increase the number of these studies and select the suitable training method for this group of athletes.</p><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0985/a.php" alt="Hit counter" /></p>

Assessment of accelerometer-derived data in the context of seat height changes in cycling and the impact on running in triathlon

Triathlon has been an Olympic sport since the 2000 Sydney Olympics and has developed rapidly, leading to variations in race categories. Although running after cycling necessitates a postural change from a non-weight-bearing activity to a weight bearing one, no study has quantified the magnitude of trunk acceleration during cycling in different seat positions and the consequential effect on running. Therefore, this study was conducted to evaluate the effectiveness of a triaxial accelerometer to determine acceleration magnitudes of the trunk in a 20 km outdoor cycling event in two seat positions that were immediately followed by a 5 km overground run. Interpretation of data was evaluated based on cadence changes while triathletes cycled in an aerodynamic position in two seat positions. Running data was evaluated based on sinusoidal curves and foot strike peaks. The evaluation of accelerometer derived data within a characteristic overground setting suggests that cycling in an adjusted seat position significantly reduced trunk acceleration in both longitudinal and mediolateral directions with large effects ( p < 0.0001, d > 0.9). A significant and large effect was found in both longitudinal and anteroposterior trunk acceleration in post-cycle running between seat positions ( d > 0.9, p < 0.0001). In the longitudinal direction, a significant reduction in trunk acceleration occurred when running after the seat was adjusted with participants completing the 5 km run faster (21:55 ± 3:17 min compared to 22:05 ± 2:53 min). The results suggest that when the seat position is adjusted based on individual anthropometrics, overall trunk acceleration magnitude is reduced in both cycling and running. Accessible and practical sensor technology could be beneficial for postural considerations in triathlons.

Runners Employ Different Strategies to Cope With Increased Speeds Based on Their Initial Strike Patterns

In this paper we examined how runners with different initial foot strike pattern (FSP) develop their pattern over increasing speeds. The foot strike index (FSI) of 47 runners [66% initially rearfoot strikers (RFS)] was measured in six speeds (2.5–5.0 ms−1), with the hypotheses that the FSI would increase (i.e., move toward the fore of the foot) in RFS strikers, but remain similar in mid- or forefoot strikers (MFS) runners. The majority of runners (77%) maintained their original FSP by increasing speed. However, we detected a significant (16.8%) decrease in the FSI in the MFS group as a function of running speed, showing changes in the running strategy, despite the absence of a shift from one FSP to another. Further, while both groups showed a decrease in contact times, we found a group by speed interaction (p &lt; 0.001) and specifically that this decrease was lower in the MFS group with increasing running speeds. This could have implications in the metabolic energy consumption for MFS-runners, typically measured at low speeds for the assessment of running economy.

Effect of Rearfoot Strikes on the Hip and Knee Rotational Kinetic Chain During the Early Phase of Cutting in Female Athletes

Background Biomechanical factors affecting horizontal-plane hip and knee kinetic chain and anterior cruciate ligament (ACL) injury risk during cutting maneuvers remain unclear. This study aimed to examine whether different foot strike patterns alter horizontal-plane hip and knee kinetics and kinematics during a cutting maneuver in female athletes and clarify the individual force contribution for producing high-risk hip and knee loadings. Twenty-five healthy female athletes performed a 60° cutting task with forefoot and rearfoot first strike conditions. Horizontal-plane hip and knee moment components, angles, and angular velocities were calculated using synchronized data of the marker positions on the body landmarks and ground reaction forces (GRFs) during the task. The one-dimensional statistical parametric mapping paired t test was used to identify the significant difference in kinetic and kinematic time-series data between foot strike conditions. Results In the rearfoot strike condition, large hip and knee internal rotation loadings were produced during the first 5% of stance due to the application of GRFs, causing a significantly larger hip internal rotation excursion than that of the forefoot strike condition. Dissimilarly, neither initial hip internal rotation displacement nor knee internal rotation GRF loadings were observed in the forefoot strike condition. Conclusions Rearfoot strike during cutting appears to increase noncontact ACL injury risk as the GRF tends to produce combined hip and knee internal rotation moments and the high-risk lower limb configuration. Conversely, forefoot strike during cutting appears to be an ACL-protective strategy that does not tend to produce the ACL-harmful joint loadings and lower extremity configurations. Thus, improving foot strike patterns during cutting should be incorporated in ACL injury prevention programs.