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Foot Strike and Injury Rates in Endurance Runners: A Retrospective Study
Abstract
This retrospective study tests if runners who habitually forefoot strike have different rates of injury than runners who habitually rearfoot strike.
We measured the strike characteristics of middle- and long-distance runners from a collegiate cross-country team and quantified their history of injury, including the incidence and rate of specific injuries, the severity of each injury, and the rate of mild, moderate, and severe injuries per mile run.
Of the 52 runners studied, 36 (69%) primarily used a rearfoot strike and 16 (31%) primarily used a forefoot strike. Approximately 74% of runners experienced a moderate or severe injury each year, but those who habitually rearfoot strike had approximately twice the rate of repetitive stress injuries than individuals who habitually forefoot strike. Traumatic injury rates were not significantly different between the two groups. A generalized linear model showed that strike type, sex, race distance, and average miles per week each correlate significantly (P < 0.01) with repetitive injury rates.
Competitive cross-country runners on a college team incur high injury rates, but runners who habitually rearfoot strike have significantly higher rates of repetitive stress injury than those who mostly forefoot strike. This study does not test the causal bases for this general difference. One hypothesis, which requires further research, is that the absence of a marked impact peak in the ground reaction force during a forefoot strike compared with a rearfoot strike may contribute to lower rates of injuries in habitual forefoot strikers.
... Several modifiable biomechanical risk factors, including greater average vertical impact loading, a rearfoot foot strike pattern (FSP), increased peak hip adduction angle, decreased peak knee flexion angle, increased knee joint stiffness, and reduced step rate (Bredeweg et al., 2013a;Ceyssens et al., 2019;Daoud et al., 2012;Davis et al., 2016;Messier et al., 2018;Milner et al., 2006;Napier et al., 2018;Noehren et al., 2011;Noehren et al., 2013), have been linked to RRIs in individual studies; however, the association is weakened when the evidence is pooled Ceyssens et al., 2019). In a prospective study of female runners, those with greater loading rates (> 66 BW/s) were 2.7 times more likely to sustain an injury that required medical attention (n = 103) compared to those who had never been injured (n = 21) (Davis et al., 2016). ...
... A single biomechanical risk factor cannot account for all running-related injuries; instead, a complex interplay of multiple biomechanical risk factors are likely involved (Willwacher et al., 2022). Approximately 70-90 % of runners in traditional shoes use a habitual rearfoot strike (RFS) pattern (Daoud et al., 2012;Lieberman et al., 2010;Warr et al., 2015). When compared to non-rearfoot strike (NRFS) runners, RFS runners have greater average vertical loading rates (AVLR), greater peak braking forces, greater negative work of the ankle dorsiflexors, and greater negative work of the knee extensors than runners using a NRFS pattern (Goss and Gross, 2013;Xu et al., 2021). ...
... When compared to non-rearfoot strike (NRFS) runners, RFS runners have greater average vertical loading rates (AVLR), greater peak braking forces, greater negative work of the ankle dorsiflexors, and greater negative work of the knee extensors than runners using a NRFS pattern (Goss and Gross, 2013;Xu et al., 2021). In competitive cross-country runners, those using a RFS pattern have demonstrated a twofold greater frequency of repetitive stress RRIs than runners using a forefoot strike (Daoud et al., 2012). Additionally, rearfoot strike recreational runners have demonstrated an almost 6 times greater relative risk of sustaining a knee injury compared to non-rearfoot strike runners (Morris et al., 2020). ...
... 2,3 Using a high-speed digital video camera at 240 or 180 frames per second (fps), foot strike patterns were visually classified into two or three types based on the initial contact point of the foot with the surface. Visual classification is predominantly utilized in field-based observational studies to assess the incidence of RRI for each foot strike pattern type, 16,17 or to analyze step variables in track events or road races. 2,3 In these earlier studies, participants were filmed from a sagittal perspective, often from outside the running track, and foot strike patterns were assessed using two-dimensional (2D) images. ...
... Previous observational studies, which used 2D visual classification for foot strike patterns, have revealed differences in the type of RRI between foot strike patterns. 16,17 While these studies referenced the aforementioned 3D motion capture-based investigations in their discussions, it is worth noting that the methods used for foot strike pattern assessments varied across the studies. Therefore, it is essential to clarify the degree of agreement between the SI, SA, and visual methods for foot strike assessment to apply laboratory findings to visual-based observational studies or clinical practice. ...
... Previous observational studies have revealed that NRFS runners are three times more likely to experience RRI at their Achilles tendon than RFS runners 17 and that RFS runners have a two-fold higher rate of RRI than NRFS runners. 16 These studies utilized 2D visual-based methods for assessing foot strike patterns via high-speed movies, while also referencing 3D motion capture-based studies in their discussions. NRFS runners exhibited greater force applied around the Achilles tendon and triceps surae compared to RFS runners in those studies, suggesting a heightened risk of Achilles tendinopathy. ...
Background
Foot strike patterns during running are typically categorized into two types: non-rearfoot strike (NRFS) and rearfoot strike (RFS), or as three distinct types: forefoot strike (FFS), midfoot strike (MFS), and RFS, based on which part of the foot lands first. Various methods, including two-dimensional (2D) visual-based methods and three-dimensional (3D) motion capture-based methods utilizing parameters such as the strike index (SI) or strike angle (SA), have been employed to assess these patterns. However, the consistency between the results obtained from each method remains debatable.
Hypothesis/Purpose
The purpose of this study was to examine the agreement for assessing foot strike patterns into two (NRFS and RFS) or three types (FFS, MFS, and RFS) between 2D visual- and 3D motion capture-based methods. The authors hypothesized that using two description types (NRFS and RFS) would have high inter-method reliability; however, using three description types (FFS, MFS and RFS) would have lower inter-method reliability because of the difficulty in distinguishing between FFS and MFS.
Study design
Controlled Laboratory Study
Methods
Overall, 162 foot strikes from four healthy runners with various foot strike patterns were analyzed. Running kinematics and kinetics were recorded using a 3D motion capture system with a force platform. Each foot strike was filmed at 240 fps from the sagittal perspective. The visual, SI, and SA methods were used, and the kappa values for each method were calculated.
Results
An assessment of the two types of foot strike: NRFS and RFS, revealed almost perfect kappa values (κ = 0.89–0.95) among the visual, SI, and SA methods. In contrast, an assessment of the three types: FFS, MFS, and RFS, revealed relatively low kappa values (κ = 0.58–0.71). Kappa values within the NRFS category, which includes MFS and FFS, ranged from fair to slight (κ = 0.08–0.33).
Conclusion
Previous laboratory findings that categorized foot strike patterns into two distinct types may be applied in observational studies, clinical practice, and training situations.
Level of evidence
Level 2
... These days, running can be regarded as one of the most common leisure activities [8]. Some studies have found that the majority of subjects were rearfoot strikers (RFS), while others have characterized forefoot striking as natural but not all barefoot runners prefer a forefoot strike pattern [15]. ...
... As a rule, forefoot strikers (FFS) make contact with the ground for less time than do rearfoot strikers [10,16]. So the forefoot strikers are less prone to injury than rearfoot strikers [8,21,28]. This link between injuries and foot strike patterns has not been clarified [2]. ...
... FFS and RFS differ in their values for maximum plantar pressure [5,21,31]. The FFS are less prone to injury because the lower maximum pressure under the heel results in less strain on the rearfoot than in RFS [8,21]. Study results vary on plantar pressure distribution subsequent to strenuous running over various distances (10 kilometres to marathon and 30-minute runs respectively). ...
The purpose of this study was to assess plantar pressure deviations due to fatigue and foot strike pattern. Plantar pressure was assessed using a Zebris treadmill. Male runners (N = 52) volunteered in a laboratory test with repeated measures on the treadmill (11, 13, 15 km/h) in a randomized order, each running speed one minute. The fatigue protocol of plantar flexors (PF) and dorsiflexors (DF) consisted of an isometric strength test and an isokinetic endurance strength test. The rearfoot striker (RFS) showed higher values in the strength test than the forefoot striker (FFS). Both groups showed marked differences in the plantar pressure distribution in the baseline and after fatigue protocol. For injury prevention the plantar muscles of FFS should be strengthened through strength training.
... On the other hand, what is not similar is that general population runners are more likely to become injured in the knee 8 and elite athletes are more likely to become injured in the lower leg. [4][5][6][7] This could be due to a number of reasons but is most likely because elite runners have higher rates of using a forefoot strike 71-75% 4,9 while recreational runners are more likely to heel strike at 95.1%. 10 This difference in foot strike drastically changes loading mechanisms in the leg as described by Cavanagh et al. 11 and Lieberman et al. 12 Another factor includes significant changes in intensities and speeds for elite runners during training while general population runners are more likely stick to an easy or moderate pace for the vast majority of their runs. While the running speed for each independent general population runner varies very little depending on the day, the population of sub elite runners as a whole has much more diversity in running skill level than in elite runners. ...
... Because of the intense physical stress these athletes put on their bodies on a daily basis, and the lack of preventative/maintenance related medical availability at smaller colleges in particular, an easy way to determine if and where an athlete has potential for injury is needed by coaches and medical staff. Studies going back to the 1990's have described the high injury rates in distance runners 4,5,6,7,8,13,14 and even with that knowledge, injury rates do not seem to be going down. Clearly there needs to be implementation of a simple test that the coaching staff, weight training staff, and medical staff can implement and understand. ...
... Of the 42 subjects, 38 (90.5%) experienced an injury over the eight-week period. These findings were at a much higher rate than found in previous studies, both sub elite runners 8,14,[23][24][25] and elite runners [4][5][6][7]14,26 which found anywhere between 19.4%-79.3% injury in sub elite runners and 55-84% injury rate in elite runners. ...
... Una de las consideraciones de mayor trascendencia en el trail running es la técnica de carrera, ya que investigaciones indican que las diferencias en la forma de correr pueden incidir en las tasas generales de lesiones y, por ende, en el rendimiento (Daoud et al., 2012). Además, la necesidad constante de adaptarse a superficies cambiantes somete al organismo a un estrés fisiológico y biomecánico considerable (Mocanu, 2015). ...
... Así, se reportaron datos de prevalencia de esguinces del 11,5% (Chandran et al., 2021a), o un 22,0% (Wu et al., 2021). Las contracturas presentan datos del 18,7% (Chandran et al., 2021a), y hasta un 21,5% (Daoud et al., 2012). ...
... No obstante, Wu et al. (2021) muestra valores más altos para las mujeres (22,5%) que para los hombres (21,6%) para el esguince de tobillo, aunque en este caso los valores son semejantes entre sexos. En cambio, las contracturas presentan prevalencias algo mayores que los esguinces, en corredores de crosscountry con datos de 5,8% en mujeres según Kerr et al. (2016); hasta el valor más alto de 21,5% según Daoud et al. (2012). ...
El objetivo del estudio fue identificar las lesiones más frecuentes entre corredores de trail running, comparándolas con las lesiones en corredores de cross-country y orientación, analizando la prevalencia e incidencia de lesiones en ambos perfiles de deportistas. Se realizó una revisión sistemática considerando las bases de datos Web of Science, Medline, Scopus y Sport Discuss, siguiendo la declaración PRISMA y la estrategia PICOS. Se obtuvieron 3160 artículos; se seleccionaron 19. Se analizó el riesgo de sesgo mediante la escala de calidad JBI y la escala de evidencia científica CEBM. Los resultados revelan que los corredores de trail running informaron de un mayor porcentaje de lesiones en el tobillo (49,5%) en términos de la ubicación anatómica y tendinopatías (29,8%) en lo que respecta al diagnóstico. Por otro lado, los corredores de cross-country y orientación mostraron un mayor porcentaje de lesiones en la rodilla (14,6%) en cuanto a la ubicación anatómica, así como afecciones inflamatorias y dolor (20,2% en hombres y 33,6% en mujeres en cross-country; 75,41% en corredores de orientación) según el diagnóstico. En lo que respecta a la incidencia, en el trail running, las tasas oscilan entre 1,6 y 187,9 por cada 1000 horas de carrera, mientras que en el cross-country son más bajas, variando entre 3,96 y 17 por cada 1000 exposiciones. Palabras clave: Lesiones, corredores, trail running, cross-country, orientación. Abstract. The objective of the study was to identify the most frequent injuries among trail running runners, comparing them with injuries in cross-country and orienteering runners, analyzing the prevalence and incidence of injuries in both profiles of athletes. A systematic review was conducted considering Web of Science, Medline, Scopus and Sport Discuss databases, following the PRISMA statement and the PICOS strategy. A total of 3160 articles were obtained; 19 were selected. The risk of bias was analysed using the JBI quality scale and the CEBM scientific evidence scale. The results reveal that trail runners reported a higher percentage of ankle injuries (49.5%) in terms of anatomical location and tendinopathies (29.8%) in terms of diagnosis. On the other hand, cross-country and orienteering runners showed a higher percentage of knee injuries (14.6%) in terms of anatomical location, as well as inflammatory conditions and pain (20.2% in men and 33, 6% in women in cross-country; 75.41% in orienteering runners) according to the diagnosis. Regarding the incidence, in trail running, the rates oscillate between 1.6 and 187.9 per 1000 hours of running, while in cross-country they are lower, varying between 3.96 and 17 per every 1000 exposures. Keywords: Injuries, runners, trail running, cross-country, orientation.
... Dado que el pie del corredor es el punto de contacto con el suelo, este tiene la doble responsabilidad de absorber el impacto durante el contacto inicial y transmitir la fuerza aplicada al cuerpo para generar el desplazamiento del mismo 11,12 . Precisamente por ello, el patrón de contacto inicial del pie (FSP, por sus siglas en inglés) ha recibido una atención significativa dentro de las comunidades científicas tanto en relación con el rendimiento deportivo como con el desarrollo de RRI 11,[13][14][15] . La interpretación más sencilla del FSP clasifica el contacto inicial del pie distinguiendo entre quienes lo realizan con el talón (rearfoot strike [RFS]) y quienes no (non-rearfoot strike [NRFS]). ...
... Dado que una carga acumulativa excesiva y una mala relación entre trabajo y la recuperación pueden resultar en una adaptación inadecuada al entrenamiento y un incremento del riesgo de lesiones 28,29 , algunos autores han defendido que ciertos tipos de FSP pueden desencadenar RRI 10,11,13,18,30 . Si bien es cierto que el tipo FSP determina en buena medida la gran solicitación de unas u otras estructuras de la extremidad inferior, la relación entre el FSP y la aparición de lesiones aún debe ser esclarecida. ...
... Daoud y cols. 13 realizaron un análisis retrospectivo enfocado en evaluar la relación entre los patrones de contacto del pie durante la carrera (específicamente RFS y NRFS) y la incidencia de lesiones repetitivas por estrés. El estudio categorizó las lesiones como leves, moderadas y severas, y encontró que los corredores con un patrón habitual de NRFS presentaban ratios significativamente menores de lesiones en comparación con aquellos con un patrón habitual de RFS para todas las categorías de gravedad. ...
This paper examines the relationship between long-distance runners’ foot strike patterns (Rearfoot Strike [RFS] and Non Rearfoot Strike [NRFS]) and various aspects such as injuries, performance, and biomechanics. While running has established itself as a popular activity with cardiovascular, respiratory, and psychological benefits, it carries a significant risk of injuries. It was found that most runners adopt an RFS pattern, which tends to increase with distance covered and the use of cushioned footwear. Although some studies suggest a relationship between certain foot strike patterns and specific injuries, there is insufficient evidence to recommend changes in foot strike patterns for injury prevention. Elite runners tend to use an NRFS pattern more than amateurs, but the relationship between foot strike patterns, performance, and biomechanical variables is complex and varies indivually. It concludes that health professionals and coaches should consider these variations when advising runners on training techniques and strategies, prevention, treatment, and rehabilitation of injuries.
... Undeniably, running can be accompanied by high rates of musculoskeletal injuries, namely the range of running-related injuries from a minimum of 2.5 to a maximum of 33.0 per 1000 h (Videbaek et al., 2015). Different foot strike patterns may influence the risks of running injuries, rearfoot strike (RFS) with high injury rates of tibial stress, plantar fasciitis, knee pain, and forefoot strike (FFS) with a higher risk of Achilles tendinopathies and metatarsal stress fractures (Daoud et al., 2012;Xu et al., 2021). The vertical ground reaction force (vGRF) has been one of the most important dynamic variables in gait feature analysis and sports injury monitoring (Almeida et al., 2015;Daoud et al., 2012;Xu et al., 2021). ...
... Different foot strike patterns may influence the risks of running injuries, rearfoot strike (RFS) with high injury rates of tibial stress, plantar fasciitis, knee pain, and forefoot strike (FFS) with a higher risk of Achilles tendinopathies and metatarsal stress fractures (Daoud et al., 2012;Xu et al., 2021). The vertical ground reaction force (vGRF) has been one of the most important dynamic variables in gait feature analysis and sports injury monitoring (Almeida et al., 2015;Daoud et al., 2012;Xu et al., 2021). Compared to forefoot strikers, rearfoot strikers experience a higher impact peak and loading rate, which may lead to an increased risk of impactrelated injuries to the lower extremity (Almeida et al., 2015). ...
... Compared to forefoot strikers, rearfoot strikers experience a higher impact peak and loading rate, which may lead to an increased risk of impactrelated injuries to the lower extremity (Almeida et al., 2015). Therefore, how to accurately collect the ground reaction forces is one of the most critical processes in the analysis of running injuries (Daoud et al., 2012;Ngoh et al., 2018). In regular experiments, the force platform is a gold standard for obtaining ground reaction force (GRF) in the stance phase (Joo et al., 2016;Oh et al., 2013), which mainly requires a stable location and professional post-processing in the laboratory-based environment based on fixed-force platforms or instrumented treadmills (Honert et al., 2020;Joo et al., 2016;Kluitenberg et al., 2012;Oh et al., 2013). ...
This study proposed a simple method for selecting input variables by factor loading and inputting these variables into a wavelet neural network (WNN) model to predict vertical ground reaction force (vGRF). The kinematic data and vGRF of 9 rearfoot strikers at 12, 14, and 16 km/h were collected using a motion capture system and an instrumented treadmill. The input variables were screened by factor loading and utilized to predict vGRF with the WNN. Nine kinematic variables were selected, corresponding to nine principal components, mainly focusing on the knee and ankle joints. The prediction results of vGRF were effective and accurate at different speeds, namely, the coefficient of multiple correlation (CMC) > 0.98 (0.984-0.988), the normalized root means square error (NRMSE) < 15% (9.34-11.51%). The NRMSEs of impact force (8.18-10.01%), active force (4.92-7.42%), and peak time (7.16-12.52%) were less than 15%. There was a small number (peak, 4.12-6.18%; time, 4.71-6.76%) exceeding the 95% confidence interval (CI) using the Bland-Altman method. The knee joint was the optimal location for estimating vGRF, followed by the ankle. There were high accuracy and agreement for predicting vGRF with the peak and peak time at 12, 14, and 16 km/h. Therefore, factor loading could be a valid method to screen kinematic variables in artificial neural networks.
... Los FSP parecen estar influenciados por numerosos factores internos como el sexo, la edad y la condición física (Ferber, McClay Davis, & Williams III, 2003;Fukuchi, Stefanyshyn, Stirling, Duarte, & Ferber, 2014;Sinclair & Selfe, 2015) y factores externos tales como las superficies para correr, la velocidad de carrera, la experiencia deportiva y el calzado (Daoud et al., 2012;Hollander et al., 2018;Lieberman et al., 2010;Gruber, Silvernail, Brueggemann, Rohr, & Hamill, 2013;An, Rainbow, & Cheung, 2015;Latorre-Román et al., 2015). Diversos estudios previos han demostrado que los FSP, tanto en adultos como en niños, se ven influidos de manera muy relevante por el calzado deportivo (Almeida, Davis, & Lopes, 2015;P.Á. ...
... Por tanto, aunque correr con FFS parece ser una característica de la evolución humana (Daoud et al., 2012), los corredores de resistencia amateur adultos muestran una alta prevalencia (entre el 74,9% y el 95,4%) de RFS (Hasegawa et al., 2007;Larson et al., 2011;Pedro Ángel Latorre-Román et al., 2015). Lieberman et al. (2010) sugieren que los corredores descalzos con un FFS tienen una fuerza de impacto en el suelo tres veces menor que los corredores descalzos o usando calzado con un patrón de RFS. ...
... Es plausible por tanto que los corredores con un RFS con cargas de impacto crecientes puedan correr un mayor riesgo de desarrollar una lesión. Así, el RFS se ha asociado con una mayor carga vertical, mayores fuerzas de colisión y una mayor rigidez en el tobillo (Almeida et al., 2015;Butler, Crowell, & Davis, 2003;Hamill, Gruber, & Derrick, 2014;Lieberman et al., 2010) y algunos trabajos anteriores han sugerido su asociación con un mayor riesgo de lesiones por esfuerzo repetitivo (Daoud et al., 2012). Además, se ha asociado a la lesión otras variables relacionadas con los FSP como son la eversión del retropié (Pohl, Hamill, & Davis, 2009) y la rotación externa tibial en relación con el fémur (Barton, Levinger, Menz, & Webster, 2009). ...
Los juegos tradicionales mexicanos son una propuesta lúdica para ser rescatada
por los docentes y se propone su implementación desde los estudiantes de la licenciatura en Educación Física, para que los den a conocer y practiquen con niños y jóvenes en escuelas de educación básica (preescolar, primaria y secundaria).
Los juegos tradicionales se presentan como una propuesta motriz que contribuye
a la formación integral de los individuos. En este sentido, los alumnos de educación
básica al experimentar y vivenciar este tipo de juegos tendrán alternativas diferentes para recrearse en su tiempo libre y adoptar hábitos de ejercicio físico saludable, ya que la principal característica de estos juegos son su riqueza motriz.
Hablar de juegos tradicionales mexicanos es hablar de nuestra riqueza cultural,
que ha sido heredada por nuestros antepasados, no practicarlos es negar nuestra cultura.
Es lamentable saber que niños y jóvenes, e incluso adultos, desconocen muchos
juegos tradicionales. Ante esta situación, los juegos tradicionales mexicanos son una
propuesta vista desde la ludomotricidad para ser vivenciada por las nuevas
generaciones.
... Nonetheless, researchers have developed running pattern retraining to reduce impact loading as foot strike patterns influence the vertical loading rates [14,15]. For rearfoot strike, heel landing produces an immediate and distinct impact peak in the vertical GRF early in the stance phase, unlike forefoot and midfoot strike, where landing on the toe or midfoot does not produce a distinct impact peak in the early stance phase [16][17][18][19]. The local impact peak during rearfoot strike is associated with higher loading rates and running injuries [6,18,20,21], potentially contributing to a 2.5 times higher injury rate in this running type than forefoot runners [16]. ...
... For rearfoot strike, heel landing produces an immediate and distinct impact peak in the vertical GRF early in the stance phase, unlike forefoot and midfoot strike, where landing on the toe or midfoot does not produce a distinct impact peak in the early stance phase [16][17][18][19]. The local impact peak during rearfoot strike is associated with higher loading rates and running injuries [6,18,20,21], potentially contributing to a 2.5 times higher injury rate in this running type than forefoot runners [16]. ...
Foot strike patterns influence vertical loading rates during running. Running retraining interventions often include switching to a new foot strike pattern. Sudden changes in the foot strike pattern may be uncomfortable and may lead to higher step-to-step variability. This study evaluated the effects of running with an imposed and usual foot strike on vertical loading rate variability and amplitude. Twenty-seven participants (16 men and 11 women; age range: 18–30 years) ran on an instrumented treadmill with their usual foot strike for 10 min. Then, the participants were instructed to run with an unusual foot strike for 6 min. We calculated the vertical instantaneous and vertical average loading rates and their variances over 200 steps to quantify vertical loading rate variability. We also calculated the amplitude and variability of the shank acceleration peak using an inertial measurement unit. The vertical loading rate and shank acceleration peak amplitudes were higher when running with a rearfoot strike, regardless of the foot strike conditions (i.e., usual or imposed). The vertical loading rate and shank acceleration peak variability were higher when running with an imposed rearfoot strike than when running with a usual forefoot strike. No differences were found in the vertical loading rate and shank acceleration peak variabilities between the imposed forefoot strike and usual rearfoot strike conditions. This study offers compelling evidence that adopting an imposed (i.e., unusual) rearfoot strike amplifies loading rate and shank acceleration peak variabilities.
... Foot strike patterns and their potential relevance to the running economy, defined as the oxygen uptake (VO 2 ) or energy expenditure during running at a given submaximum velocity, have long been of interest to researchers in sports science and anthropology. During running, foot strike patterns have three types: rearfoot strikes (RFS, the heel contacts the ground first), forefoot strikes (the ball of the foot contacts the ground before the heel), and midfoot strikes (the heel and ball of the foot contact the ground simultaneously) (Daoud et al., 2012). Forefoot and midfoot strikes are also classified as non-RFS (Anderson et al., 2020). ...
... Foot strike patterns were identified based on the previously proposed classification (Daoud et al., 2012). RFS refers to patterns in which the heel first touches the ground. ...
... Laufen ist eine einfache und kostengünstige Möglichkeit, um Gewicht zu verlieren, Stress abzubauen oder die kardiovaskuläre Fitness zu steigern [1]. Die Anzahl an Ausdauerläufer*innen erhöhte sich in den letzten Jahren, und damit auch die laufassoziierten Beschwerden [2,3]. Deswegen beschäftigten sich viele Studien mit den unterschiedlichen Fußaufsatztechniken beim Laufen und konzentrierten sich auf Vorfuß-und Rückfußläufer*innen [4,5]. ...
... Diese Ergebnisse stimmen mit anderen Studien überein [8,34,35,36]. Verschiedene Autor*innen gehen davon aus, dass Vorfußläufer*innen aufgrund der geringeren Belastung unter der Ferse ein niedrigeres Verletzungsrisiko aufweisen [2,8,34]. Andere Autor*innen nehmen wiederum an, dass ein Zusammenhang zwischen Fußaufsatztechnik und Verletzungsrisiko nicht erwiesen ist [37,38]. ...
... Recent study on various styles of running has focused on the distinctions between heel and mid/forefoot foot strikes in terms of potential injury risks and shock absorption capacities. 13 According to contentious and arbitrary estimates, heel striking is frequently associated with higher injury rates due to damage [3] and impact because of insufficient shock absorption and ineffective biomechanical compensations for these forces. This is owing to the fact that blows from heel strikes are absorbed by bones rather than muscles, which are responsible for shock absorption. ...
... Those shock waves are initiated by most types of motion such as walking and running. The demarcation between walking and running occurs when periods of double support during the stance phase of the gait cycle (both feet are simultaneously in contact with the ground) give way to two periods of double float at the beginning and the end of the swing phase of gait (neither foot is touching the ground) [3]. Generally, as speed increases further, initial contact changes from being on the hindfoot to the forefoot. ...
The objective of this thesis was to determine the effect of fatigue on impact shock wave attenuation and assess how human biomechanics relate to shock attenuation during running. In this paper, we propose a new methodology for the analysis of shock events occurring during the proposed experimental procedure. Our approach is based on the Shock Response Spectrum (SRS), which is a frequency-based function that is used to indicate the magnitude of vibration due to a shock or a transient event. Five high level CrossFit athletes who ran at least three times per week and who were free from musculoskeletal injury volunteered to take part in this study. Two Micromachined Microelectromechanical Systems (MEMS) accelerometers (RunScribe®, San Francisco, CA, USA) were used for this experiment.Injuries in running are often provoked by fatigue or improper technique, which are both reflected in the runner’s kinematics. State of the art research on kinetics and kinematics in sports is using motion analysis systems that are inaccessible to most athletes. The potential of wearable sensors for runners’ kinetic and kinematics analysis is extremely relevant and cost effective. Throughout our research we demonstrate the potential of wearable sensors for runners’ kinetic and kinematics analysis. We present several studies using inertial measurement units (IMU) for performance level assessment, training assistance, and fatigue monitoring. We extracted many gait parameters for performance and health assessments. Wearable sensors provide a valuable tool for runners, from beginners to experts, for running technique assessment.Our hypothesis is that fatigue leads to a decrease in the shock attenuation capacity of the musculoskeletal system, thus potentially implying a higher risk of overuse injury
... 4 Runners who forefoot strike are at increased risk of Achilles tendon injuries due to increased ankle total mechanical work and plantarflexor eccentric demands. 1,[5][6][7][8] Conversely, a rearfoot strike pattern may decrease total mechanical work at the ankle and reduce the risk for Achilles tendon injury. 9 Modifying lower extremity mechanics with real-time visual feedback while utilizing a faded feedback schedule has been previously supported for the rehabilitation of running injuries. ...
... Use of a rearfoot strike, as compared to a nonrearfoot strike, likely decreases peak plantarflexion moment and plantarflexors eccentric demands while running, reducing the risk of Achilles injury. 1,[7][8][9]12 Moreover, the clinical practice guidelines for the management of Achilles pain and/or tendinopathy recommend the use of neuromuscular reeducation to retrain abnormal kinetics/kinematics in weightbearing movements, to reduce excessive eccentric demands on the Achilles tendon. 28 Our suggested intervention strategy for this case series is supported by this recommendation. ...
Introduction
Running-related injuries are prevalent in the military and are often related to physical fitness test training. Non-rearfoot striking while running is known to increase the risk of Achilles tendon injuries because of the high eccentric energy absorption by the elastic components of the planarflexor muscle-tendon complex. However, there is limited evidence to suggest benefits of converting runners with Achilles tendon pain to use a rearfoot strike.
Methods
This is a case series of two active-duty Service members with chronic, running-related Achilles tendon pain that utilized a natural non-rearfoot strike pattern. Both patients were trained to utilize a rearfoot strike while running through the use of real-time visual feedback from wearable sensors.
Results
The trained rearfoot strike pattern was retained for over one month after the intervention, and both patients reported improvements in pain and self-reported function.
Conclusions
This case series demonstrated the clinical utility of converting two non-rearfoot strike runners to a rearfoot strike pattern to decrease eccentric demands on the plantarflexors and reduce Achilles tendon pain while running.
... The recurrence of injuries is common and studies have shown that running injuries frequently result in individuals cutting back or discontinuing running activity (van Mechelen, 1992). Some research suggests that running with rear-foot strikes is associated with greater injury (e.g., Arendse et al., 2004;Daoud et al., 2012), especially an increase in knee-impact injuries. Moreover, runners who run with mid-foot strikes and front-foot strikes tend to use shorter stride length or stride reach, and increased step rate or cadence (Heiderscheit et al., 2011;Kumar et al., 2015). ...
... These strike patterns are desirable to promote running technique when knee-impact injuries are a concern. Considering the majority of runners typically use a rear-foot strike pattern (Daoud et al., 2012;Kleindienst et al., 2007), it is not surprising that a major site of injury is the knee, ranging from 7.2% to 50% of injuries (van Gent et al., 2007). ...
Correct running form is important for injury prevention; as such, correct form promotes continued engagement in running as a long-term form of exercise. Researchers have shown video feedback to be an effective strategy to improve athletic form for a variety of sports, but it has not been evaluated in any behavior analytic research as a method for improving running form. The purpose of this study is to evaluate the effectiveness of video feedback to improve running form for regular runners. During baseline, each participant was video recorded while running without any feedback (verbal or video). During intervention, the researcher recorded the participant, then showed them the video and provided feedback on correct or incorrect form, according to a 9-step task analysis. Results show that all three participants achieved 100% correct steps on the task analysis when video feedback was used to maintain their form during follow-up. K E Y W O R D S feedback, injury, running form, video analysis, video feedback
... Foot strike patterns (FSPs) are of increasing interest to researchers as one of the risk factors associated with RRIs (Daoud et al., 2012;Hall et al., 2013). Compared to rearfoot strike pattern (RFS), non-rearfoot strike pattern (NRFS) is frequently considered a more economical running technique (Anderson et al., 2020;DiMichele & Merni, 2014;Lieberman et al., 2010). ...
... In addition, amateur runners prefer RFS, whilst elite runners prefer NRFS (Hanley et al., 2019;Hasegawa et al., 2007;Larson et al., 2011). Evidence indicated that RFS runners are more susceptible to repetitive stress injuries than NRFS runners (Daoud et al., 2012;Yao et al., 2021). Therefore, the biomechanical performance of the lower extremity in NRFS runners must be clarified. ...
This study aims to determine the validity of the lower extremity joint kinematics measured by inertial measurement units (IMUs) in non-rearfoot strike pattern (NRFS) runners across different speeds. Fifteen NRFS runners completed three 2-min running tests on a treadmill in random order at 8, 10 and 12 km/h, whilst data were synchronously collected using the IMU system and an optical motion capture system. Before the offset was corrected, the validity of the knee angle waveform was higher than that of the hip and ankle; after the offset was corrected, the validity increased in all three joints. The correlation between the touchdown angles in the sagittal plane measured by the two systems was relatively high after the offset was corrected. The running speed influenced the offset-corrected measurements, with higher error values at higher speeds. The IMU system was able to provide measurements of running kinematics in the sagittal plane of NRFS runners at different running speeds but was unable to reliably measure motion in the frontal and horizontal planes. Future research should analyse the 3D gait of NRFS runners under a larger range of speed conditions to provide evidentiary support for the use of IMUs in running analysis outside the laboratory.
... Thus, it has been shown that shifting towards an FFS produces virtually the same effects as barefoot running (Futrell et al., 2020;Xu et al., 2021). Likewise, the evidence indicates that runners with a FFS are less injured than those who run with a rearfoot strike pattern (RFS) (where the heel strikes the ground first) (Daoud et al., 2012). ...
... During the last time, the interest in modifying the running technique towards forefoot strike became an important aim since there is some evidence that relates it with a lower incidence injury rate (Daoud et al., 2012), which could be related to reducing the vertical loading rates experimented by the plantar support (Futrell et al., 2020;Lieberman et al., 2010;Sun et al., 2018). This triggered an interest in studying the modifications that BFR causes over the foot strike pattern. ...
Heel-to-toe drop (HTD) values may modify the running biomechanics. However, more than twenty additional footwear characteristics may contribute to this too. The aim of this review was to identify and systematise the specific effects caused by different HTDs on running bio-mechanics. A systematic search was carried out in seven online databases and Footwear Science according to PRISMA protocol for studies that included the practice of endurance running in running shoes with different HTD types. A modified Downs and Black checklist was used to assess the risk of bias. Characteristics of the studies and footwear, the equipment used, and bio-mechanical outcomes were extracted for qualitative synthesis. Twelve studies were included. Only one had a randomised control trial design, which was classified as 'good' (score ¼ 24) quality. The studies reported thirty-nine kinematic and sixteen kinetic variables. HTD ranged between À8 to 16 mm. HTDs did not produce modifications in contact and flight time, stride frequency, and stride length. Some controversial evidence supports that the foot strike pattern changes towards forefoot strike only with HTD 0 compared to HTD 8-10. All evidence indicates that HTD values modified neither ankle, knee, or hip kinematics. Greater evidence supports that the modification of HTD in running shoes does not modify the values of GRF. Despite the controversial nature of the data, the trend is that a lower HTD shows a higher vertical loading rate. The different HTDs modified neither of the joint moments. The negative HTD could be an interesting variable to consider for future research. In addition, it is necessary to study the relationship between the HTD values and different combinations of heel height and forefoot height.
... Particularly, running gait assessment is paramount in providing injury prevention and rehabilitation mechanisms through quantifying the factors pertaining to the unique patterns of limb movement and co-ordination [3]. For example, runners exhibiting a rear-foot strike have been found to be at almost twice the risk of a repetitive strain injury in comparison to those with a fore or mid-foot strike [4]. As such, identifying and adapting small changes such as strike location to the running stride can minimize injury risk. ...
... Understanding running gait is crucial in performance optimization and providing mechanisms for injury prevention and rehabilitation [4]. Providing low-cost mechanisms to measure running gait beyond bespoke settings is important to enabling accessibility and assessments for a wider range of individuals. ...
Running gait assessment is essential for development of technique optimization strategies as well as to inform injury prevention and rehabilitation. Currently, running gait assessment relies on (i) visual assessment, exhibiting subjectivity and limited reliability, or (ii) use of instrumented approaches, which often carry high costs and can be intrusive due to attachment of equipment to the body. Here use of an IoT-enabled markerless computer vision smartphone application based upon Googles pose estimation model BlazePose was evaluated for running gait assess-ment for use in low-resource settings. That human pose estimation architecture was used to ex-tract contact time, swing time, step time, knee flexion angle and foot strike location from a large cohort of runners. The gold-standard Vicon 3D motion capture system was used as a reference. The proposed approach performs robustly, demonstrating good (ICC(2,1) > 0.75) to excellent (ICC(2,1) > 0.90) agreement in all running gait outcomes. Additionally, temporal outcomes exhibit low mean error (0.01-0.014s) in left foot outcomes. However, there are some discrepancies in right foot outcomes, due to occlusion. This study demonstrates that the proposed low-cost and markerless system provides accurate running gait assessment outcomes. The approach may help routine running gait assessment in low-resource environments.
... Running technique is one of the most important components in studying running efficiency and performance [1]; additionally, improper technique increases the risk of injury [2][3][4]. ...
Our aim was to validate a sacral-mounted inertial measurement unit (IMU) for reconstructing running kinematics and comparing movement patterns within and between runners. IMU data were processed using Kalman and complementary filters separately. RMSE and Bland–Altman analysis assessed the validity of each filtering method against a motion capture system. Running data from 24 recreational runners were analyzed using Fourier transform coefficients, PCA, and k-means clustering. High agreement was found for Kalman-filtered data in the frontal, sagittal, and transverse planes, with a Bland–Altman bias of ~2 mm on average, compared to a bias of ~10.5 mm for complementary-filtered data. Pelvic angles calculated from Kalman-filtered data had superior agreement, with systematic biases of ~0.3 versus 3.4 degrees for complementary-filtered data. Our findings suggest that inertial sensors are viable alternatives to motion capture for reconstructing pelvic running kinematics and movement patterns. In the second part of our study, negligible intra-individual differences were observed with changes in speed, while inter-individual differences were large. Two clusters of runners were identified, each showing distinct movement patterns and ranges of motion. These observations highlight the potential usefulness of inertial sensors for performance analysis and rehabilitation as they may permit the use of individual-specific and cluster-specific practice programs.
... Although running appears to be a simple activity that require little more than a pair of shoes, it is, in fact, a complex exercise that demands precise coordination of the body's joints, muscles, and nervous system 4 . The complexity of running mechanics contributes to a high injury risk, with studies showing injury rates J o u r n a l P r e -p r o o f ranging from 18% to 92% among runners 5 . This wide variation could be partly attributed to the inconsistent definitions of running-related injuries and the diverse characteristics of individual runners. ...
In recent years' research, the scientific and clinical communities have shown increased interest in the differences between foot strike patterns due to their biomechanical implications and the associated injury risks. This review aims to investigate the biomechanical differences between habitual forefoot and rearfoot strike running. A literature search across three databases identifies 671 articles using Boolean operators, with specific eligibility criteria applied to refine the results. After a detailed screening, 11 articles meet the inclusion criteria for this review. Compared with rearfoot strike (RFS) runners, the findings reveal that forefoot strike (FFS) runners land with a plantar-flexed ankle and greater hip and knee flexion, enhancing cushioning and reducing knee joint forces, which may lower the risk of knee injuries such as patellofemoral pain syndrome. This FFS improves running efficiency by increasing leg stiffness and generating ankle plantarflexion moments that facilitate elastic rebound. However, the greater reliance on the ankle and calf muscles in FFS running elevates the risk of achilles tendon injuries and plantar fasciitis. In contrast to FFS runners, RFS runners land with a dorsiflexed ankle, resulting in higher impact peaks and loading rates that transfer mechanical load to the knee, increasing the risk of knee injuries. The differences in ground reaction forces and muscle activation patterns between FFS and RFS running highlight the significant influence of foot strike mechanics on both running performance and injury risk. These insights provide valuable information, enhancing the understanding of human movement for the prevention of sports injury, supporting injury management and training optimization, such as retraining runners with patellofemoral pain toward the FFS or refining techniques to enhance performance.
... This study provides the performance characteristics of the ViMove2 system for temporal running gait outcomes, which can be used to determine whether future results are meaningful (e.g., differences in performance are beyond error (mean bias) in the outcome). Understanding the accuracy and reliability of running gait outcomes from relatively low-cost commercial wearable technology is crucial in providing specific data to determine error rate and will allow calculation of minimal important differences in future work [39], which is vital to implementation in applied settings and to reduce reliance on expert analysis and/or gold-standard, high-cost technologies [40]. ...
Running biomechanics have traditionally been analysed in laboratory settings, but this may not reflect natural running gait. Wearable technology has the potential to enable precise monitoring of running gait beyond the laboratory. This study aimed to evaluate the analytical validity and intra-session reliability of temporal running gait outcomes measured by the ViMove2 wearable system in healthy adults. Seventy-four healthy adults (43 males, 31 females, aged 18–55 years) wore the inertial device, ViMove2 on the tibia. Participants ran on a treadmill for one minute at various speeds (8, 10, 12, 14km/hr), completed in a standardised shoe (Saucony Guide Runner). Running gait was measured with the ViMove2 wearable and 3D motion capture (Vicon). Temporal running gait outcomes included ground contact time (GCT) and cadence (steps/min). GCT and cadence from the ViMove2 had face validity with expected changes in outcome with different running speeds, but ViMove2 tended to over-estimate GCT, and under-estimate cadence compared to the reference, especially at slower speeds. GCT demonstrated moderate to good agreement to the reference at speeds >10km/hr, but poor agreement at 8km/hr and within female runners. Cadence had moderate to excellent agreement across speeds compared to the reference. GCT and cadence had excellent reliability across speeds, but at 8km/hr GCT had good agreement between trials. Overall, temporal gait outcomes of GCT and cadence can be measured with the ViMove2, but accuracy and reliability are impacted at slow running speeds and within female runners. Future work is needed to clarify sex or speed-dependent corrections to algorithms / outcomes to aid interpretation and application.
... Corredores que realizam corridas de duração mais prolongada, frequentemente reportam desconforto e ocorrência de lesões cutâneas como bolhas ou dores em regiões especificas do pé. Os desconfortos estão associados a descargas de peso impostas durante movimentos repetitivos (1). Os principais acometimentos musculoesqueléticos são as síndromes de estresse do medial tibial, tendinites, fasciítes plantares e fraturas do quinto metatarso (2)(3)(4). ...
Introdução: Conhecer como a sensibilidade cutânea, a pressão plantar e a estabilidade mudam em resposta ao exercício de corrida pode ajudar treinadores e fisioterapeutas e melhor planejar a recuperação pós-exercício. A aplicação prática desse conhecimento envolve não apenas esportistas em treinamento, mas também em processos de reabilitação. Objetivo: Examinar os efeitos agudos de uma corrida de 5 km sobre a sensibilidade e a pressão plantares e sobre o controle postural em atletas amadores de corrida de fundo. Métodos: Estudo quasi-experimental, do qual participaram 11 corredores (sexo masculino, com médias: de idade 35±15 anos; de estatura 1,75±0,05m e de massa corporal 77,70±8,70kg. Foram avaliados: sensibilidade tátil plantar (estesiômetro), pressão plantar (baropodômetro) e controle postural (centro de pressão durante a postura em pé) pré, imediatamente após, 15min e 30min uma sessão de corrida de 5 km em uma esteira. Resultados: Houve aumento significativo na sensibilidade tátil do mediopé, na pressão plantar média e na área de contato na região do antepé, com efeitos que perduraram por até 15 min após o término do exercício. As medidas de controle postural indicaram maior oscilação corporal, especialmente na direção anteroposterior até 30min após o exercício. Conclusão: A escolha de exercícios, após uma sessão de corrida, deve considerar o efeito negativo agudo sobre a capacidade de controle postural em corredores, decorrentes de um deslocamento do peso corporal à frente, aumentando a demanda de pressão no mediopé e no antepé e, possivelmente, requerendo maior recrutamento do tríceps sural para a manutenção do controle da estabilidade.
... The top one is responsible for the aesthetics, the frictional behavior and wear/environmental resistance. The bottom one, whose characteristics govern the dynamic behavior of the track, affects instead the safety and performance of the athletes [2][3][4][5][6][7][8]. The production process of prefabricated tracks allows the introduction of honeycomb patterns or similar geometries to further enhance surface properties of a given material [9,10]. ...
This investigation deals with the problem of identifying the mechanical behaviour of rubbers from compression tests, performed on specimens having unfavorable geometry. A typical situation is that of flat specimens obtained from high-friction sports surfaces. To this purpose, experimental tests were conducted, aimed at measuring friction under various conditions and evaluating its effect on the compressive behavior of different rubber samples. The experimental results have been interpreted in view of an existing analytical model proposed by Gent and coworkers. The method was shown to be valid within a relatively broad range of conditions (in terms of materials, lubrication and aspect ratio). Its application allowed the creation of virtual “frictionless” curves, by rescaling experimental data for the stiffening factor predicted by Gent model. These curves represent more closely the intrinsic material behaviour, removing the large frictional contribution present in the experimental tests, and can be used as a more reliable input for numerical simulations.
... Firstly, technological footwear often has a high heel-to-toe drop, which implies a significant height difference between the heel and forefoot. 43,44 This design may promote a more forward-leaning posture, which in turn limits ankle DF and shortens the posterior chain musculature. 45 Furthermore, some models of technological footwear incorporate restrictive technologies, such as structural reinforcements in the back of the shoe, which can restrict natural ankle movement. ...
Background
Technological running shoes have become increasingly popular, leading to improvements in performance. However, their long-term effects on foot musculature and joint mobility have not been thoroughly studied.
Objective
To compare the activation of the intrinsic foot muscles between runners wearing technological footwear and barefoot runners. Secondary objectives included assessing ankle dorsiflexion (DF) range of motion (ROM) and dynamic postural control in both groups.
Methods
A cross-sectional study was conducted involving 22 technological footwear runners and 22 barefoot runners. Ultrasonography was used to measure the thickness of the plantar fascia (PF) and the quadratus plantae (QP), abductor digiti minimus (ADM), abductor hallucis (AH), and flexor hallucis longus (FHL) muscles. Ankle mobility and dynamic postural control were also recorded.
Results
Ultrasonography measurements showed statistically significant differences for PF thickness (mean difference [MD]: -0.10 cm; 95% CI: -0.13, -0.05 cm), QP cross-sectional area (CSA) (MD: -0.45 cm²; 95% CI: -0.77, -0.12 cm²), ADM CSA (MD: -0.49 cm²; 95% CI: -0.70, -0.17 cm²), and FHL thickness (MD: 0.82 cm; 95% CI: 0.53, 1.09 cm), with all measurements being lower in the group wearing technological footwear compared to the barefoot runners. Ankle DF ROM was also significantly greater for the barefoot runners (MD: -5.1°; 95% CI: -8.6, -1.7°).
Conclusions
These findings suggest potential implications for the foot musculature and ankle mobility in runners using technological footwear.
... In the field of running research, various striking methods, such as forefoot strike (FFS), midfoot strike (MFS) and rearfoot strike (RFS), have become the subject of research focus [6], [31]. Past research has revealed that most runners use the RFS method, while fewer choose the FFS method [12], [13]. With the continued focus on running technique and performance, sports scientists and coaches have been working tirelessly to understand the impact of different running patterns on the athletes' leg movement ability and overall performance [19], [20], [39], [40]. ...
Purpose
This study aims to explore the impact of different landing methods on leg movement ability and the relationship between various parameters of leg movement.
Methods
This work parameters including stride, contact time, flight time, duty factor, stride angle, vertical stiffness, leg stiffness, and peak vertical ground reaction force. Thirty healthy subjects voluntarily participated in this study. In this experiment, each subject was required to perform two tests on a treadmill (using a speed of 10 km/h and 160 spm) (The interval between two experiments is 7 days). In the first test, subjects used RFS. In the second test, FFS was used. A high-speed video camera was used to collect the images and the Kwon3D motion analysis suite was used to process the images in this experiment.
Results
The findings of this study revealed that runners employing the forefoot strike FFS method exhibited several favorable characteristics in contrast to those using the rearfoot strike RFS method. These included shorter contact time, longer flight time, reduced duty cycle, increased stride angle, and heightened leg stiffness. Additionally, peak vertical ground reaction forces were significantly elevated in females.
Conclusions
While rear foot strike RFS demonstrates a notable enhancement in leg stiffness among female runners with low leg stiffness, it concurrently leads to a significant increase in peak vertical ground reaction force and imposes a greater load on the legs. However, this phenomenon is not observed among male participants.
... Moreover, unsafe ground and low or high temperatures restrict running barefoot. Minimalist footwear, derived from barefoot running theory, has been applied to clinical, laboratory and sports fields [6,[17][18][19][20]. These running practices have encouraged researchers to investigate the effects of running barefoot versus in shoes on injury mechanisms, biomechanics and performance [21]. ...
Minimal shoes may alter ankle kinematics while running. This study aimed to systematically review studies investigating ankle kinematics in runners while wearing minimalist shoes versus traditional shoes and barefoot. Four databases including PubMed (128 studies), Web of science (224), Scopus (242 studies) and Embase (148 studies) were searched from inception to Aug 9, 2022. Two reviewers screened studies to identify studies reporting the effects of minimal shoes on ankle kinematics during running. Eleven studies with a total of 203 (wearing minimal shoes) participants and 18 controls (8 participants wearing minimal shoes without gait training and 10 wearing standard shoes) were included. The study design of the included studies were RCTs (2 studies), prospective study (1), cross-sectional study (5), and crossover (3). The Downs and Black appraisal scale was applied to assess the quality of included studies. The results showed that minimal shoe was capable of changing the kinematics of ankle while running. Uncushioned minimal shoes decreased ankle dorsiflexion at initial contact and ankle adduction, and increased plantarflexion moment, strike index, total ROM and joint excursion in stance phase compared to traditional shoes. Standardizing shoes and speeds are needed for reliable comparisons among studies. Because most studies examining the efficacy of minimal shoes, had a low level of evidence, further studies providing valid and high-quality evidence which include RCTs are required to support clinical practice in the use of minimal shoes. Uncushioned minimal shoes are better replicating barefoot running. Therefore, it is recommended for runners since they can change their foot strike pattern to mid-foot or forefoot and consequently reduce peak impact force, resulting in preventing future injuries especially in the knee.
... Nowadays, running can be considered one of the most important leisure activities (9). In recent years, many studies have addressed the various foot strike patterns in running (6,13,18,24,34). ...
... Moreover, it is well-established that a majority of runners experience Running-Related Injuries (RRIs) [3][4][5][6][7]. Extensive research has been conducted on factors contributing to RRIs, encompassing variables such as time and distance of exposure, exercise load and environment, running skills, fatigue, and history of trauma [8][9][10][11][12][13][14][15][16][17][18][19]. In popular marathons, participants are subject to signi cant exposure in terms of both distance and time, leading to biomechanical changes [20][21][22][23]. ...
Running is a widely-accepted activity among the general public, with runners aspiring to achieve optimal performance. However, established methods for the regular monitoring of running forms is lacking. To address this gap, we explore a versatile visualization method utilizing the widely-adopted Inertial Measurement Unit sensor. The running forms of 17-year-old male high school students were monitored during long-distance running training. Acceleration and angular velocity data were collected from a sensor attached to the lumbar region; data from the left foot contact to the next left foot contact were defined as the running cycle. Fatigue during running was assessed using the Borg Scale. The distribution of principal component scores obtained from functional principal component analysis of the running form data corresponded to changes in fatigue from one measurement session to another. However, no consistent trends or changes were observed across subjects. The running forms of participants who were measured twice exhibited a close distribution and similarity, yet unique features were also observed during each measurement. The findings suggest that changes and characteristics of runners' running forms can be readily visualized using a generic approach based on commonly-used sensors and functional data analysis.
... During a race, body tissues (muscles, fascia, tendons, bones, etc.) are stressed by different forces, mainly tension, compression, and torsion. Injuries occur when these impacts are greater than the absorption threshold of the tissues; therefore, the control of load peaks generated by these forces is essential for the prevention and even the treatment of pathologies due to overload [3]. One of the fastest ways to modulate loading rates is through the footwear that athletes wear [4]. ...
This study aimed to investigate if the characteristics of different running shoes could influence intra-abdominal pressure during running. A single-centre, randomized, prospective cross-over clinical trial was performed measuring activity patterns of internal oblique (IO), lumbar erector (LE), and gluteus maximus (GM) muscles in healthy women when running with minimalist shoes (MS). Participants were randomly allocated into two-sequence (MS/TS or TS/MS) treadmill running at six, nine, and eleven km/h. The surface electromyographic activity of IO, LE, and GM muscles were recorded while running. A repeated measures ANOVA explored the interaction effects of three-muscle x three speeds x two shoes. Significance was set at p ≤ 0.05. Fifty-one healthy nulliparous women (mean age: 26.55 ± 5.11 years; body mass index: 21.29 ± 2.07 Kg/m2) were included. Our findings revealed lower activations of the LE compared to the internal oblique IO and GM, irrespective of running speed and footwear used. Electromyographic activation significantly increased with higher running speeds (p < 0.001) for all muscles, regardless of the type of footwear. Although electromyographic records with MS consistently showed higher values than those with TS, the differences were not statistically significant for all muscles at all speeds. Our results indicate that electromyographic activation patterns vary according to the muscle group, exhibiting higher values with increased running speed. No significant differences were observed between MS and TS.
... In a forefoot strike, the forefoot contacts the ground rst, usually followed by the heel touching the ground. The FFS pattern is known to be a type that allows the foot to run quickly and e ciently forward due to a decrease in braking force after landing on the ground [7,15]. Most running studies done on foot strike patterns have predominantly focused on ground reaction force (GRF) peaks, and knee joint angles and moments. ...
Background
The purpose of this study is to examine the kinematic and kinematic variables during running with various foot strike patterns and to calculate the knee ligament loading using musculoskeletal modeling techniques.
Methods
Twenty participants were instructed to run overground at 4.3 ± 0.2 m/s along the instrumented runway, with landing their feet on the force plate under three foot strike patterns: forefoot (foot strike angle < -1.6°), midfoot (-1.6° < foot strike angle < -8.0°), rearfoot (foot strike angle > 8.0°). The angle, angular velocity, ground reaction force (GRF), and moment of the knee joint were calculated, and anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) forces were determined through musculoskeletal modeling.
Results
The forefoot strike had a significant shorter contact time than the midfoot and rearfoot strike (p < .05). The forefoot strike was lower than other foot strike patterns for flexion angle (F = 7.261, p = .005). In the kinetic variables, the forefoot strike showed single vertical GRF peak that was higher than the first or second peaks in other foot strike patterns (p < .05). The anterior and posterior ACL loading of the rearfoot strike were lower than forefoot and midfoot strike patterns (p < .05), while no significant between strike patterns were found in PCL loading.
Conclusion
This suggests that the lower ACL load of the rearfoot strike would be associated with the two-peak GRF characteristics with the impact attenuation at initial contact, and that forefoot strike showed a relatively high ACL load due to the small foot contact area for both landing and propulsion.
... In the eld of running research, various striking methods, such as forefoot strike (FFS), midfoot strike (MFS), and rearfoot strike (RFS), have become the subject of research focus [2][3] . Past research has revealed that most runners use the RFS method, while fewer choose the FFS method [4][5] . With the continued focus on running technique and performance, sports scientists and coaches have been working tirelessly to understand the impact of different running patterns on the athletes' leg movement ability and overall performance. ...
This study explores the impact of different landing methods on leg movement ability and the relationship between leg movement ability parameters. This work parameters including stride, contact time, flight time, duty factor, stride angle, vertical stiffness, leg stiffness, and peak vertical ground reaction force. Thirty healthy subjects voluntarily participated in this study. In this experiment, each subject was required to perform two tests on a treadmill (using a speed of 10 km/h and 160 spm) (The interval between two experiments was more than seven days). In the first test, subjects used RFS. In the second test, FFS was used. A high-speed video camera was used to collect the images and the Kwon3D motion analysis suite was used to process the images in this experiment. The results of this study show that compared with the RFS method, runners using the FFS method have several positive characteristics, including short contact times, extended flight times, reduced duty factor, increased stride angle, and increased leg stiffness. This study did not show a significant difference in the peak vertical ground reaction force, but the FFS approach is generally ac-companied by greater vertical reaction force, further emphasizing its positive advantages in improving overall athletic ability.
... There is currently some controversy regarding how foot strike location (rearfoot, midfoot, or forefoot) may impact ground reaction forces and injury risk in runners. Notably, some studies have suggested that rearfoot strike patterns are associated with an increased injury risk, [33][34][35] which may be due to elevated ground reaction forces during initial ground contact in these runners. A meta-analysis by Almeida et al. also indicated that rearfoot strike patterns yield a higher vertical loading rate at ground contact. ...
There is limited data quantifying the influence of running on hip cartilage mechanics. The goal of this investigation was to quantify changes in hip joint bone‐to‐bone distance in response to a 3‐mile treadmill run. We acquired magnetic resonance (MR) images of the dominant hip of eight young, asymptomatic runners (5 males, 3 females) before and immediately after they ran 3 miles at a self‐selected pace on a level treadmill. The femoral heads and acetabula were semi‐automatically segmented from the pre‐ and post‐exercise MR images to generate three‐dimensional models of each participant's hip that were used to compute changes in the bone‐to‐bone distances incurred by the running exercise. We observed a significant 3% decrease in bone‐to‐bone distance from 3.47±0.20 mm to 3.36±0.22 mm between the femoral head and acetabulum after a 3‐mile treadmill run (mean ± 95% confidence interval; p=0.03). These findings provide new baseline data describing how running impacts the hip joint in young, asymptomatic runners.
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... On the other hand, knee joint negative work increased in MAX shoes, in which the knee joint is the most common site of lower limb running-related injuries [35]. Although the load on the knee joint is higher, thicker shoes may be useful for non-rearfoot strikers to reduce ankle joint load because forefoot strikers have a lower risk of knee joint injuries than rearfoot strikers [8]. As for the MIN shoes, they seem to be beneficial for rearfoot strikers to reduce the impact of landing by shifting their strike patterns to more mid/forefoot strikes [23], [27]. ...
Purpose
To investigate the effects of midsole thickness on non-rearfoot strike runners’ redistributions of knee and ankle joint negative and positive work.
Methods
Fourteen healthy male runners wore minimalist, traditional, and maximalist shoes and ran in a straight line in each shoe in the laboratory at a speed of 15 km/h, with a ±5% difference being allowed. Whole-body kinematics and ground reaction forces were recorded, and the data of eleven non-rearfoot strikers were used for the analysis. Ankle and knee joint negative and positive work was calculated by integrating each joint's torque power. Friedman test was used for statistical comparisons.
Results
Minimalist shoes induced significantly greater ankle joint negative and positive work than in other shoes. Maximalist shoes induced significantly lower ankle joint positive work and greater knee joint negative work than in other shoes, and significantly greater knee joint positive work than in minimalist shoes.
Conclusions
Our results indicated that non-rearfoot strikers redistributed joint negative and positive work from the knee to the ankle when using minimalist shoes or from the ankle to the knee when using maximalist shoes. It is recommended that future research employs more rigorous study designs, such as randomised controlled trials and longitudinal studies, to provide a more accurate assessment of the effect of these shoes on injury rates.
... This contributes to reductions in knee extensor moment needed during running and decrease load to the patellofemoral joint. Conversely, collegiate runners may experience foot/ankle pathologies due to additional reliance on the ankle plantar flexors (33)(34)(35). ...
Introduction
Running related injuries (RRI) are common, but factors contributing to running performance and RRIs are not commonly compared between different types of runners.
Methods
We compared running biomechanics previously linked to RRIs and performance between 27 recreational and 35 collegiate runners. Participants completed 5 overground running trials with their dominant limb striking a force plate, while outfitted with standardised footwear and 3-dimensional motion capture markers.
Results
Post hoc comparisons revealed recreational runners had a larger vertical loading rate (194.5 vs. 111.5 BW/s, p < 0.001) and shank angle (6.80 vs. 2.09, p < 0.001) compared with the collegiate runners who demonstrated greater vertical impulse (0.349 vs. 0.233 BWs, p < 0.001), negative impulse (−0.022 vs. −0.013 BWs, p < 0.001), positive impulse (0.024 vs. 0.014 BWs, p < 0.001), and propulsive force (0.390 vs. 0.333 BW, p = 0.002). Adjusted for speed, collegiate runners demonstrated greater total support moment (TSM), plantar flexor moment, knee extensor moment, hip extensor moment, and had greater proportional plantar flexor moment contribution and less knee extensor moment contribution to the TSM compared with recreational runners. Unadjusted for speed, collegiate runners compared with recreational had greater TSM and plantar flexor moment but similar joint contributions to the TSM.
Discussion
Greater ankle joint contribution may be more efficient and allow for greater capacity to increase speed. Improving plantarflexor function during running provides a strategy to improve running speed among recreational runners. Moreover, differences in joint kinetics and ground reaction force characteristics suggests that recreational and collegiate runners may experience different types of RRI.
... Manipulation of running mechanics to reduce AT loads has been investigated and may be an effective method to manage AT injuries (Almonroeder et al., 2013; T. W. Kernozek et al., 2018;Lyght et al., 2016;Rice & Patel, 2017). A rearfoot strike (RFS) pattern has been associated with decreased risk of Achilles tendinopathy in females, with up to four times as many forefoot strike (FFS) runners reporting Achilles' tendinopathy in comparison to rearfoot strikers (Daoud et al., 2012). Studies have shown a higher AT stress (about 24%) in forefoot strikers compared to rearfoot strikers (Almonroeder et al., 2013;Lyght et al., 2016). ...
Running has a high incidence of overuse injuries. Achilles tendon (AT) injuries may occur due to high forces and repetitive loading during running. Foot strike pattern and cadence have been linked to the magnitude of AT loading. The effect of running speed on AT stress and strain, muscle forces, gait parameters and running kinematics is not well addressed in recreational runners with lower pace of running. Twenty-two female participants ran on an instrumented treadmill between 2.0 and 5.0 m/s. Kinetic and kinematic data were obtained. AT cross-sectional area data were collected using ultrasound imaging. Inverse dynamics with static optimization was used to calculate muscle forces and AT loading. AT stress, strain and cadence increased with greater running speed. Foot inclination angle indicated a rearfoot strike pattern among all participants, which increased as running speed increased but the latter plateaued after 4.0 m/s. The soleus contributed more force in running compared to the gastrocnemius throughout all speeds. Highest running speeds had the most stress on the AT, with changes to foot inclination angle and cadence. Understanding the relation of AT loading variables with running speed may aid in understanding how applied load may influence injury.
... According to foot strike pattern, there are three main types of running patterns: rearfoot strike (RFS), midfoot strike (MFS), and forefoot strike (FFS) [12]. Research relating to running strike patterns found that 75% of runners were habitually rearfoot-strikers [13]. ...
Background:
Although numerous studies have been conducted to investigate the acute effects of shoe drops on running kinematics and kinetic variables, their effects on muscle forces remain unknown. Thus, the primary aim of this study was to compare the muscle force, kinematics, and kinetic variables of habitually rearfoot runners with heel-to-toe drops of negative 8 mm shoes (minimalist shoes) and positive 9 mm shoes (normal shoes) during the running stance phase by using musculoskeletal modeling and simulation techniques.
Methods:
Experimental data of lower limb kinematics, ground reaction force, and muscle activation from 16 healthy runners with rearfoot strike patterns were collected and analyzed in OpenSim. Using Matlab, the statistical parameter mapping paired t-test was used to compare the joint angle, moment, and muscle force waveform.
Results:
The results revealed differences in the sagittal ankle and hip angles and sagittal knee moments between the different heel-to-toe drops of running shoes. Specifically, it showed that the negative 8 mm running shoes led to significantly smaller values than the positive 9 mm running shoes in terms of the angle of ankle dorsiflexion, ankle eversion, knee flexion, hip flexion, and hip internal and hip external rotation. The peak ankle dorsiflexion moment, ankle plantarflexion moment, ankle eversion moment, knee flexion moment, knee abduction moment, and knee internal rotation also decreased obviously with the minimalist running shoes, while the lateral gastrocnemius, Achilleas tendon, and extensor hallucis longus muscles were obviously greater in the minimalist shoes compared to normal shoes. The vastus medialis, vastus lateralis and extensor digitorum longus muscles force were smaller in the minimalist shoes.
Conclusions:
Runners may shift to a midfoot strike pattern when wearing negative running shoes. High muscle forces in the gastrocnemius lateral, Achilleas tendon, and flexor hallucis longus muscles may also indicate an increased risk of Achilleas tendonitis and ankle flexor injuries.
... Running strike patterns affected the mode of impact attenuation and force transmission that could be associated with the risks of injury (Daoud et al., 2012). It has been shown that forefoot strike (FFS) running may have implications for protecting the foot and lower limbs from some impact-related injuries due to the reduction or lack of the first impact peak in the vertical ground reaction force (GRF) and lower vertical GRF loading rates when compared to rearfoot strike (RFS) running (Cheung and Davis, 2011;Diebal et al., 2012). ...
A carbon-fiber plate (CFP) embedded into running shoes is a commonly applied method to improve running economy, but little is known in regard the effects of CFP design features on internal foot mechanics. This study aimed to explore how systematic changes in CFP geometrical variations (i.e., thickness and location) can alter plantar pressure and strain under the forefoot as well as metatarsal stress state through computational simulations. A foot-shoe finite element (FE) model was built and different CFP features including three thicknesses (1 mm, 2 mm, and 3 mm) and three placements (high-loaded (just below the insole), mid-loaded (in between the midsole), and low-loaded (just above the outsole)) were further modulated within the shoe sole. Simulations were conducted at the impact peak instant during forefoot strike running. Compared with the no-CFP shoe, peak plantar pressure and compressive strain under the forefoot consistently decreased when the CFP thickness increased, and the low-loaded conditions were found more effective (peak pressure decreased up to 31.91% and compressive strain decreased up to 18.61%). In terms of metatarsal stress, CFP designs resulted in varied effects and were dependent on their locations. Specifically, high-loaded CFP led to relatively higher peak metatarsal stress without the reduction trend as thickness increased (peak stress increased up to 12.91%), while low-loaded conditions showed a gradual reduction in peak stress, decreasing by 0.74%. Therefore, a low-loaded thicker CFP should be considered to achieve the pressure-relief effects of running shoes without the expense of increased metatarsal stress.
... In both prospective and cohort studies, a high weekly running volume has been associated with running-related injuries (Macera et al., 1989;Walter et al., 1989). Although the causes of running injuries are multifactorial, in this context, the runner's interaction with the ground and the resulting reaction force has been considered to be one risk factor (Zadpoor and Nikooyan, 2011;Daoud et al., 2012). Thus, higher loading rates were associated with increased risk of sustaining an injury (Crowell and Davis, 2011;Futrell et al., 2018). ...
The time spent above 90% of maximal oxygen uptake ( V ̇ O2max) during high-intensity interval training (HIIT) sessions is intended to be maximized to improve V ̇ O2max. Since uphill running serves as a promising means to increase metabolic cost, we compared even and moderately inclined running in terms of time ≥90% V ̇ O2max and its corresponding physiological surrogates. Seventeen well-trained runners (8 females & 9 males; 25.8 ± 6.8yrs; 1.75 ± 0.08m; 63.2 ± 8.4kg; V ̇ O2max: 63.3 ± 4.2 ml/min/kg) randomly completed both a horizontal (1% incline) and uphill (8% incline) HIIT protocol (4-times 5min, with 90s rest). Mean oxygen uptake ( V ̇ O2mean), peak oxygen uptake ( V ̇ O2peak), lactate, heart rate (HR), and perceived exertion (RPE) were measured. Uphill HIIT revealed higher (p ≤ 0.012; partial eta-squared (pes) ≥ 0.351) V ̇ O2mean (uphill: 3.3 ± 0.6 vs. horizontal: 3.2 ± 0.5 L/min; standardized mean difference (SMD) = 0.15), V ̇ O2peak (uphill: 4.0 ± 0.7 vs. horizontal: 3.8 ± 0.7 L/min; SMD = 0.19), and accumulated time ≥90% V ̇ O2max (uphill: 9.1 ± 4.6 vs. horizontal: 6.4 ± 4.0 min; SMD = 0.62) compared to even HIIT. Lactate, HR, and RPE responses did not show mode*time rANOVA interaction effects (p ≥ 0.097; pes ≤0.14). Compared to horizontal HIIT, moderate uphill HIIT revealed higher fractions of V ̇ O2max at comparable perceived efforts, heartrate and lactate response. Therefore, moderate uphill HiiT notably increased time spent above 90% V ̇ O2max.
Recent reports have suggested that there may be a relationship between footstrike pattern and overuse injury incidence and type. With the recent increase in wearable sensors, it is important to identify paradigms where the footstrike pattern can be detected in real-time from minimal data. Machine learning was used to classify tibial acceleration data into three distinct footstrike patterns: rearfoot, midfoot, or forefoot. Tibial accelerometry data were collected during treadmill running from 58 participants who each ran with rearfoot, midfoot, and forefoot strike patterns. These data were used as inputs into an artificial neural network classifier. Models were created by using three distinct acceleration data sets, using the first 100%, 75%, and 40% of stance phase. All models were able to predict the footstrike pattern with up to 89.9% average accuracy. The highest error was associated with the identification of the midfoot versus forefoot strike pattern. This technique required no pre-selection of features or filtering of the data and may be easily incorporated into a wearable device to aid with real-time footstrike pattern detection.
Running injuries are prevalent, but their exact mechanisms remain unknown largely due to limited real-world biomechanical analysis. Reducing overstriding, the horizontal distance that the foot lands ahead of the body, may be relevant to reducing injury risk. Here, we leverage the geometric relationship between overstriding and lower extremity sagittal segment angles to demonstrate that wearable inertial measurement units (IMUs) can predict overstriding during treadmill and overground running in the laboratory. Ten recreational runners matched their strides to a metronome to systematically vary overstriding during constant-speed treadmill running and showed similar overstriding variation during comfortable-speed overground running. Linear mixed models were used to analyze repeated measures of overstriding and sagittal segment angles measured with motion capture and IMUs. Sagittal segment angles measured with IMUs explained 95% and 98% of the variance in overstriding during treadmill and overground running, respectively. We also found that sagittal segment angles measured with IMUs correlated with peak braking force and explained 88% and 80% of the variance during treadmill and overground running, respectively. This study highlights the potential for IMUs to provide insights into landing and loading patterns over time in real-world running environments, and motivates future research on feedback to modify form and prevent injury.
Recent reports have suggested that high loading rates during running, typically associated with a rearfoot strike pattern, may be related to overuse injuries. With the recent increase in wearable sensors, it is important to identify paradigms where the footstrike pattern can be detected in real-time from minimal data. Machine learning was used to identify tibial acceleration data into three distinct footstrike patterns: rearfoot, midfoot, or forefoot. Tibial accelerometry data were collected during treadmill running from 58 participants who each ran with rearfoot, midfoot, and forefoot strike patterns. These data were used as inputs into an artificial neural network classifier. Models were created by using three distinct acceleration data sets, using the first 100%, 75%, and 40% of stance phase. All models were able to predict the footstrike pattern with up to 91.6% average accuracy. Highest error was associated with the identification of the midfoot versus forefoot strike pattern. This technique required no pre-selection of features or filtering of the data and may be easily incorporated into a wearable device to aid with real-time footstrike pattern detection. This technology could be used to help runners navigate a footstrike pattern transition.
Background
Movement quality is typically assessed by drawing comparisons against predetermined movement standards. Movements are often discretely scored or labelled against pre-set criteria, though movement quality can also be evaluated using motion-related measurements (e.g., spatio-temporal parameters and kinematic variables). Wearable technology has the potential to measure and assess movement quality and offer valuable, practical feedback.
Objectives
A systematic approach was taken to examine the benefits associated with multi-sensor and multiple wearable-device usage, compared with unimodal applications, when assessing movement quality. Consequently, this review considers the additional variables and features that could be obtained through multi-sensor devices for use in movement analyses. Processing methods and applications of the various configurations were also explored.
Methods
Articles were included within this review if they were written in English, specifically studied the use of wearable sensors to assess movement quality, and were published between January 2010 and December 2022. Of the 62,635 articles initially identified, 27 papers were included in this review. The quality of included studies was determined using a modified Downs and Black checklist, with 24/27 high quality.
Results
Fifteen of the 27 included studies used a classification approach, 11 used a measurement approach, and one used both methods. Accelerometers featured in all 27 studies, in isolation (n = 5), with a gyroscope (n = 9), or with both a gyroscope and a magnetometer (n = 13). Sampling frequencies across all studies ranged from 50 to 200 Hz. The most common classification methods were traditional feature-based classifiers (n = 5) and support vector machines (SVM; n = 5). Sensor fusion featured in six of the 16 classification studies and nine of the 12 measurement studies, with the Madgwick algorithm most prevalent (n = 7).
Conclusions
This systematic review highlights the differences between the applications and processing methods associated with the use of unimodal and multi-sensor wearable devices when assessing movement quality. Further, the use of multiple devices appears to increase the feasibility of effectively assessing holistic movements, while multi-sensor devices offer the ability to obtain more output metrics
There is debate and confusion over how to evaluate the biomechanical effects of running shoe design. Here we use an evolutionary perspective to analyze how key design features of running shoes alter the evolved biomechanics of the foot, creating a range of tradeoffs in force production and transmission that may affect performance and vulnerability to injury.
Background:
Foot kinematics, such as excessive eversion and malalignment of the hindfoot, are believed to be associated with running-related injuries. The majority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics. However, technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns (RFS and FFS, respectively). This study uses a high-speed dual fluoroscopic imaging system (DFIS) to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.
Methods:
Fifteen healthy male recreational runners underwent foot CT scan for the construction of 3D models. A high-speed DFIS (100 Hz) was used to collect 6 degrees of freedom kinematics for participants' tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.
Results:
Compared with RFS, FFS exhibited greater internal rotation at 0%-20% of the stance phase in the tibiotalar joint. The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS (p < 0.001, Cohen's d = 0.92). RFS showed more dorsiflexion at 0%-20% of the stance phase in the tibiotalar joint than FFS. RFS also presented a larger anterior translation (p < 0.001, Cohen's d = 1.28) in the subtalar joint at initial contact than FFS.
Conclusion:
Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance. The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RFS and FFS during running.
The main purpose of this study was to investigate the effects of both strike pat- tern (forefoot vs. rearfoot strike pattern) and orthotic intervention on shock to the lower extremity. Semi-rigid orthotic devices were manufactured for 15 injury- free recreational runners. Tibial accelerometry, ground reaction force, and 3D kinematic data were collected on their right leg in four conditions: forefoot strike (FFS) and rearfoot strike (RFS) with and without orthotics. Two-way repeated- measures analysis of variance tests were used to assess the effects of strike pat- tern and orthotic intervention on tibial acceleration; angular excursions of the ankle and knee; ground reaction force (GRF) vertical and anteroposterior peaks and load rates; and ankle, knee, and leg stiffness. There was a significant in- crease in tibial acceleration for the FFS pattern compared to the RFS pattern. This may be explained in part by the significantly greater peak vertical GRF, peak anteroposterior GRF, anteroposterior GRF load rates, knee stiffness, and leg stiffness found in the FFS pattern compared to the RFS pattern. Tibial accel- eration and rearfoot eversion excursions were similar between the orthotic and no-orthotic conditions. Knee flexion excursion and average GRF vertical load rates were significantly decreased while dorsiflexion excursion and knee stiffness were significantly increased in the orthotic condition. No significant interactions were found between strike pattern and orthotic condition for any variables assessed.
The present study examines the injury status in women runners who are randomised to receive a neutral, stability or motion control running shoe.
81 female runners were categorised into three different foot posture types (39 neutral, 30 pronated, 12 highly pronated) and randomly assigned a neutral, stability or motion control running shoe. Runners underwent baseline testing to record training history, as well as leg alignment, before commencing a 13-week half marathon training programme. Outcome measures included number of missed training days due to pain and three visual analogue scale (VAS) items for pain during rest, activities of daily living and with running.
194 missed training days were reported by 32% of the running population with the stability shoe reporting the fewest missed days (51) and the motion control shoe (79) the most. There was a significant main effect (p<0.001) for footwear condition in both the neutral and pronated foot types: the motion control shoe reporting greater levels of pain in all three VAS items. In neutral feet, the neutral shoe reported greater values of pain while running than the stability shoe; in pronated feet, the stability shoe reported greater values of pain while running than the neutral shoe. No significant effects were reported for the highly pronated foot, although this was limited by an inadequate sample size.
The findings of this study suggest that our current approach of prescribing in-shoe pronation control systems on the basis of foot type is overly simplistic and potentially injurious.
Shoe manufacturers market motion control, stability, and cushioned shoes for plantar shapes defined as low, normal, and high, respectively. This assignment procedure is presumed to reduce injuries by compensating for differences in running mechanics.
Assigning running shoes based on plantar shape will not reduce injury risk in Marine Corps basic training.
Randomized controlled clinical trial; Level of evidence, 1.
After foot examinations, Marine Corps recruits in an experimental group (E: 408 men, 314 women) were provided motion control, stability, or cushioned shoes for plantar shapes indicative of low, medium, or high arches, respectively. A control group (C: 432 men, 257 women) received a stability shoe regardless of plantar shape. Injuries during the 12 weeks of training were determined from outpatient visits obtained from the Defense Medical Surveillance System. Other known injury risk factors (eg, fitness, smoking, prior physical activity) were obtained from a questionnaire, existing databases, or the training units.
Cox regression indicated little difference in injury risk between the E and C groups among men (hazard ratio [E/C] = 1.01; 95% confidence interval, 0.82-1.24) or women (hazard ratio [E/C] = 0.88; 95% confidence interval, 0.70-1.10).
This prospective study demonstrated that assigning shoes based on the shape of the plantar foot surface had little influence on injuries even after considering other injury risk factors.
Humans have engaged in endurance running for millions of years, but the modern running shoe was not invented until the 1970s. For most of human evolutionary history, runners were either barefoot or wore minimal footwear such as sandals or moccasins with smaller heels and little cushioning relative to modern running shoes. We wondered how runners coped with the impact caused by the foot colliding with the ground before the invention of the modern shoe. Here we show that habitually barefoot endurance runners often land on the fore-foot (fore-foot strike) before bringing down the heel, but they sometimes land with a flat foot (mid-foot strike) or, less often, on the heel (rear-foot strike). In contrast, habitually shod runners mostly rear-foot strike, facilitated by the elevated and cushioned heel of the modern running shoe. Kinematic and kinetic analyses show that even on hard surfaces, barefoot runners who fore-foot strike generate smaller collision forces than shod rear-foot strikers. This difference results primarily from a more plantarflexed foot at landing and more ankle compliance during impact, decreasing the effective mass of the body that collides with the ground. Fore-foot- and mid-foot-strike gaits were probably more common when humans ran barefoot or in minimal shoes, and may protect the feet and lower limbs from some of the impact-related injuries now experienced by a high percentage of runners.
Healthcare professionals prescribe foot orthoses (FOs) for treatment and prevention of lower limb injuries, but previous reviews of the effectiveness of FOs have been inconclusive. We have therefore performed a review emphasizing the magnitude of treatment effects to evaluate the clinical effectiveness of FOs in the treatment and prevention of lower limb injuries.Qualifying studies were mainly controlled trials, but some uncontrolled clinical trials of patients with chronic injuries were analysed separately. Injuries included plantar fasciitis, tibial stress fractures and patellofemoral pain syndrome; these were included because of the large treatment costs for these frequent injuries in New Zealand. Outcomes were pain, comfort, function and injury status. Continuous measures were expressed as standardized differences using baseline between-subject standard deviations, and magnitudes were inferred from the intersection of 90% confidence intervals with thresholds of a modified Cohen scale. Effects based on frequencies were expressed as hazard ratios and their magnitudes were inferred from intersection of confidence intervals with a novel scale of thresholds.The effects of FOs for treatment of pain or injury prevention were mostly trivial. FOs were not effective in treating or preventing patellofemoral pain syndrome. Some studies showed moderate effects for treatment of plantar fasciitis. Only a few studies showed moderate or large beneficial effects of FOs in preventing injuries.Customized semi-rigid FOs have moderate to large beneficial effects in treating and preventing plantar fasciitis and posterior tibial stress fractures, and small to moderate effects in treating patellofemoral pain syndrome. Given the limited randomized controlled trials or clinical controlled trials available for the injuries of interest, it may be that more or less benefit can be derived from the use of FOs, but many studies did not provide enough information for the standardized effect sizes to be calculated. Further research with randomized controlled trials is needed to establish the clinical utility of a variety of FOs for the treatment and prevention of various lower limb injuries.
Sedentary individuals, particularly new military recruits, who start a physical training program have a substantial risk of developing an overuse injury of the lower limb. In this study we investigated the effect of neoprene insoles on the incidence of overuse injuries during 9 weeks of basic military training. The experimental group consisted of 237 randomly selected new recruits, while 1151 recruits were the control group. Insoles were given to the experimental group and compliance was monitored. A panel of doctors documented and classi fied all injuries occurring during the 9 week period. A total of 54 (22.8%) and 237 (31.9%) injuries were reported in the experimental and control groups, re spectively.
In both groups, the majority of injuries were overuse (experimental group, 90.7%; control group, 86.4%). The mean weekly incidence of total overuse injuries and tibial stress syndrome was significantly lower (P < 0.05) in the experimental group. The mean incidence of stress fractures was lower in the experimental group but not significantly so (0.05 < P < 0.1). This study shows that the incidence of total overuse injuries and tibial stress syndrome during 9 weeks of basic military training can be reduced by wearing insoles.
Physical training-related injuries are common among army recruits and other vigorously active populations, but little is known about their causation. To identify intrinsic risk factors, we prospectively measured 391 army trainees. For 8 weeks of basic training, 124 men and 186 women (79.3%) were studied. They answered questionnaires on past activities and sports participation, and were measured for height, weight, and body fat percentage; 71% of the subjects took an initial army physical training test. Women had a significantly higher incidence of time-loss injuries than men, 44.6% compared with 29.0%. During training, more time-loss injuries occurred among the 50% of the men who were slower on the mile run, 29.0% versus 0.0%. Slower women were likewise at greater risk than faster ones, 38.2% versus 18.5%. Men with histories of inactivity and with higher body mass index were at greater injury risk than other men, as were the shortest women. We conclude that female gender and low aerobic fitness measured by run times are risk factors for training injuries in army trainees, and that other factors such as prior activity levels and stature may affect men and women differently.
This article discusses the possible association between impact forces and foot pronation and the development of running-related injuries, and proposes a new paradigm for impact forces and foot pronation.
The article is based on a critical analysis of the literature on heel-toe running addressing kinematics, kinetics, resultant joint movements and forces, muscle activity, subject and material characteristics, epidemiology, and biologic reactions. However, this paper is not a review of the literature but rather an attempt to replace the established concepts of impact forces and movement control with a new paradigm that would allow explaining some of the current contradictions in this topic of research.
The analysis included all papers published on this topic over the last 25 years. For the last few years, it concentrated on papers expressing critical concerns on the established concepts of impact and movement control.
An attempt was made to find indications in the various publications to support or reject the current concept of impact forces and movement control. Furthermore, the results of the available studies were searched for indications expanding the current understanding of impact forces and movement control in running.
Data were synthesized revealing contradictions in the experimental results and the established concepts. Based on the contradictions in the existing research publications, a new paradigm was proposed.
Theoretical, experimental, and epidemiological evidence on impact forces showed that one cannot conclude that impact forces are important factors in the development of chronic and/or acute running-related injuries. A new paradigm for impact forces during running proposes that impact forces are input signals that produce muscle tuning shortly before the next contact with the ground to minimize soft tissue vibration and/or reduce joint and tendon loading. Muscle tuning might affect fatigue, comfort, work, and performance. Experimental evidence suggests that the concept of "aligning the skeleton" with shoes, inserts, and orthotics should be reconsidered. They produce only small, not systematic. and subject-specific changes of foot and leg movement. A new paradigm for movement control for the lower extremities proposes that forces acting on the foot during the stance phase act as an input signal producing a muscle reaction. The cost function used in this adaptation process is to maintain a preferred joint movement path for a given movement task. If an intervention counteracts the preferred movement path, muscle activity must be increased. An optimal shoe, insert, or orthotic reduces muscle activity. Thus, shoes, inserts, and orthotics affect general muscle activity and, therefore, fatigue, comfort, work, and performance. The two proposed paradigms suggest that the locomotor system use a similar strategy for "impact" and "movement control." In both cases the locomotor system keeps the general kinematic and kinetic situations similar for a given task. The proposed muscle tuning reaction to impact loading affects the muscle activation before ground contact. The proposed muscle adaptation to provide a constant joint movement pattern affects the muscle activation during ground contact. However, further experimental and theoretical studies are needed to support or reject the proposed paradigms.
Seventeen running training clinics were investigated to determine the number of injuries that occur in a running programme designed to minimise the injury rate for athletes training for a 10 km race. The relative contributions of factors associated with injury were also reported.
A total of 844 primarily recreational runners were surveyed in three trials on the 4th, 8th, and 12th week of the 13 week programme of the "In Training" running clinics. Participants were classified as injured if they experienced at least a grade 1 injury-that is, pain only after running. Logistic regression modelling and odds ratio calculation were performed for each sex using the following predictor variables: age, body mass index (BMI), previous aerobic activity, running frequency, predominant running surface, arch height, running shoe age, and concurrent cross training.
Age played an important part in injury in women: being over 50 years old was a risk factor for overall injury, and being less than 31 years was protective against new injury. Running only one day a week showed a non-significant trend for injury risk in men and was a significant risk factor in women and overall injury. A BMI of > 26 kg/m(2) was reported as protective for men. Running shoe age also significantly contributed to the injury model. Half of the participants who reported an injury had had a previous injury; 42% of these reported that they were not completely rehabilitated on starting the 13 week training programme. An injury rate of 29.5% was recorded across all training clinics surveyed. The knee was the most commonly injured site.
Although age, BMI, running frequency (days a week), and running shoe age were associated with injury, these results do not take into account an adequate measure of exposure time to injury, running experience, or previous injury and should thus be viewed accordingly. In addition, the reason for the discrepancy in injury rate between these 17 clinics requires further study.
Running shoes are designed to accommodate various arch types to reduce the risk of lower extremity injuries sustained during running. Yet little is known about the biomechanical changes of running in the recommended footwear that may allow for a reduction in injuries.
To evaluate the effects of motion control and cushion trainer shoes on running mechanics in low- and high-arched runners.
Controlled laboratory study.
Twenty high-arched and 20 low-arched recreational runners (>10 miles per week) were recruited for the study. Three-dimensional kinematic and kinetics were collected as subjects ran at 3.5 ms(-1) +/- 5% along a 25-m runway. The motion control shoe evaluated was the New Balance 1122, and the cushioning shoe evaluated was the New Balance 1022. Repeated-measures analyses of variance were used to determine if low- and high-arched runners responded differently to motion control and cushion trainer shoes.
A significant interaction was observed in the instantaneous loading rate such that the low-arched runners had a lower instantaneous loading rate in the motion control condition, and the high-arched runners had a lower instantaneous loading rate in the cushion trainer condition. Significant main effects for shoe were observed for peak positive tibial acceleration, peak-to-peak tibial acceleration, mean loading rate, peak eversion, and eversion excursion.
These results suggest that motion control shoes control rearfoot motion better than do cushion trainer shoes. In addition, cushion trainer shoes attenuate shock better than motion control shoes do. However, with the exception of instantaneous loading rate, these benefits do not differ between arch type.
Running footwear recommendations should be based on an individual's running mechanics. If a mechanical analysis is not available, footwear recommendations can be based empirically on the individual's arch type.
The purpose of this study was to present a systematic overview of published reports on the incidence and associated potential risk factors of lower extremity running injuries in long distance runners. An electronic database search was conducted using the PubMed-Medline database. Two observers independently assessed the quality of the studies and a best evidence synthesis was used to summarise the results. The incidence of lower extremity running injuries ranged from 19.4% to 79.3%. The predominant site of these injuries was the knee. There was strong evidence that a long training distance per week in male runners and a history of previous injuries were risk factors for injuries, and that an increase in training distance per week was a protective factor for knee injuries.
To determine whether the current practice of prescribing distance running shoes featuring elevated cushioned heels and pronation control systems tailored to the individual's foot type is evidence-based.
MEDLINE (1950-May 2007), CINAHL (1982-May 2007), EMBASE (1980-May 2007), PsychInfo (1806-May 2007), Cochrane Database of Systematic Reviews (2(nd) Quarter 2007), Cochrane Central Register of Controlled trials (2(nd) Quarter 2007), SPORTSDiscus (1985-May 2007) and AMED (1985-May 2007). Review
English language articles were identified via keyword and medical subject headings (MeSH) searches of the above electronic databases. With these searches and the subsequent review process, controlled trials or systematic reviews were sought in which the study population included adult recreational or competitive distance runners, the exposure was distance running, the intervention evaluated was a running shoe with an elevated cushioned heel and pronation control systems individualised to the wearer's foot type, and the outcome measures included either running injury rates, distance running performance, osteoarthritis risk, physical activity levels, or overall health and wellbeing. The quality of these studies and their findings were then evaluated.
No original research that met the study criteria was identified either directly or via the findings of the six systematic reviews identified.
The prescription of this shoe type to distance runners is not evidence-based.
This book provides a comprehensive treatment on modeling approaches for non-Gaussian repeated measures, possibly subject to incompleteness. The authors begin with models for the full marginal distribution of the outcome vector. This allows model fitting to be based on maximum likelihood principles, immediately implying inferential tools for all parameters in the models. At the same time, they formulate computationally less complex alternatives, including generalized estimating equations and pseudo-likelihood methods. They then briefly introduce conditional models and move on to the random-effects family, encompassing the beta-binomial model, the probit model and, in particular the generalized linear mixed model. Several frequently used procedures for model fitting are discussed and differences between marginal models and random-effects models are given attention
The authors consider a variety of extensions, such as models for multivariate longitudinal measurements, random-effects models with serial correlation, and mixed models with non-Gaussian random effects. They sketch the general principles for how to deal with the commonly encountered issue of incomplete longitudinal data. The authors critique frequently used methods and propose flexible and broadly valid methods instead, and conclude with key concepts of sensitivity analysis.
Without putting too much emphasis on software, the book shows how the different approaches can be implemented within the SAS software package. The text is organized so the reader can skip the software-oriented chapters and sections without breaking the logical flow.
Geert Molenberghs is Professor of Biostatistics at the Universiteit Hasselt in Belgium and has published methodological work on surrogate markers in clinical trials, categorical data, longitudinal data analysis, and the analysis of non-response in clinical and epidemiological studies. He served as Joint Editor for Applied Statistics (2001–2004) and as Associate Editor for several journals, including Biometrics and Biostatistics. He was President of the International Biometric Society (2004–2005). He was elected Fellow of the American Statistical Association and received the Guy Medal in Bronze from the Royal Statistical Society.
Geert Verbeke is Professor of Biostatistics at the Biostatistical Centre of the Katholieke Universiteit Leuven in Belgium. He has published a number of methodological articles on various aspects of models for longitudinal data analyses, with particular emphasis on mixed models. Geert Verbeke is Past President of the Belgian Region of the International Biometric Society, International Program Chair for the International Biometric Conference in Montreal (2006), and Joint Editor of the Journal of the Royal Statistical Society, Series A (2005–2008). He has served as Associate Editor for several journals including Biometrics and Applied Statistics.
The authors also wrote a monograph on linear mixed models for longitudinal data (Springer, 2000) and received the American Statistical Association's Excellence in Continuing Education Award, based on short courses on longitudinal and incomplete data at the Joint Statistical Meetings of 2002 and 2004.
Objectives
To assess the benefits, if any, of the use of shock absorbing insoles in reducing lower limb injury among Air Force recruits, and to assess the differences, if any, in the efficacy of two commonly available shock absorbing insoles.
Design
Randomized controlled trial. Setting: RAF Halton, UK. Site of all basic training for RAF personnel. Participants: 1205 recruits participating in basic training between 17 September 2003 and 7 April 2004. Interventions: Participants were randomized to receive either standard issue Saran non-shock absorbing insoles, or shock absorbing Sorbothane or Poron insoles, on a 1:1:1 basis.
Main Outcome Measures
The primary outcome measure was withdrawal from training for lower limb injury. The two primary comparisons were shock absorbing insole versus non-shock absorbing insole, and Sorbothane versus Poron (comparison of different shock absorbing insoles). Secondary outcomes were medical withdrawals for reasons other than those qualifying for the primary outcome measure.
Results
When comparing the non-shock absorbing insole to the shock absorbing insoles 72/401 participants (18.0%) allocated to Saran insoles were removed from training because of a qualifying lower limb injury, compared with 149/ 804 (18.5%) allocated to the shock absorbing insole (Sorbothane or Poron), odds ratio 1.04 (95% CI 0.75 to 1.44; P=0.87). When comparing the two shock absorbing insole 73/ 421 participants (17.3%) randomized to Sorbothane were removed from training because of a qualifying lower limb injury, compared with 76/383 for Poron (19.8%), odds ratio 0.85 (95% CI 0.58 to 1.23; P=0.37).
Conclusions
Similar rates of lower limb injuries were observed for all insoles (shock absorbing and non-shock absorbing) in the trial. The trial provides no support for a change in policy to the use of shock absorbing insoles for military recruits.
Runners are sometimes advised to alter their strike pattern as a means of increasing performance or in response to injury. The purpose of this study was to compare lower extremity mechanics of rearfoot strikers (RFS), who were instructed to run with a forefoot strike pattern (CFFS) to those of a preferred forefoot striker (FFS). Three-dimensional mechanics of 9 FFS and 9 CFFS were evaluated. Peak values for most kinematic and kinetic variables and all patterns of movement were not found to be statistically different between CFFS and FFS. Only peak vertical ground reaction force and peak ankle plantarflexion moment were found to be significantly lower (p ≤ .05) in the CFFS group. This suggests that RFS are able to assume a FFS pattern with very little practice that is very similar to that of a preferred FFS. The impact of changing one's strike pattern on injury risk and running performance needs further study.
Running is one of the most popular leisure sports activities. Next to its beneficial health effects, negative side effects in terms of sports injuries should also be recognised. Given the limitations of the studies it appears that for the average recreational runner, who is steadily training and who participates in a long distance run every now and then, the overall yearly incidence rate for running injuries varies between 37 and 56%. Depending on the specificity of the group of runners concerned (competitive athletes; average recreational joggers; boys and girls) and on different circumstances these rates vary. If incidence is calculated according to exposure of running time the incidence reported in the literature varies from 2.5 to 12.1 injuries per 1000 hours of running. Most running injuries are lower extremity injuries, with a predominance for the knee. About 50 to 75% of all running injuries appear to be overuse injuries due to the constant repetition of the same movement. Recurrence of running injuries is reported in 20 to 70% of the cases. From the epidemiological studies it can be concluded that running injuries lead to a reduction of training or training cessation in about 30 to 90% of all injuries, about 20 to 70% of all injuries lead to medical consultation or medical treatment and 0 to 5% result in absence from work. Aetiological factors associated with running injuries include previous injury, lack of running experience, running to compete and excessive weekly running distance. The association between running injuries and factors such as warm-up and stretching exercises, body height, malalignment, muscular imbalance, restricted range of motion, running frequency, level of performance, stability of running pattern, shoes and inshoe orthoses and running on 1 side of the road remains unclear or is backed by contradicting or scarce research findings. Significantly not associated with running injuries seem age, gender, body mass index, running hills, running on hard surfaces, participation in other sports, time of the year and time of the day. The prevention of sports injuries should focus on changes of behaviour by health education. Health education on running injuries should primarily focus on the importance of complete rehabilitation and the early recognition of symptoms of overuse, and on the provision of training guidelines.
Striding bipedalism is a key derived behaviour of hominids that possibly originated soon after the divergence of the chimpanzee and human lineages. Although bipedal gaits include walking and running, running is generally considered to have played no major role in human evolution because humans, like apes, are poor sprinters compared to most quadrupeds. Here we assess how well humans perform at sustained long-distance running, and review the physiological and anatomical bases of endurance running capabilities in humans and other mammals. Judged by several criteria, humans perform remarkably well at endurance running, thanks to a diverse array of features, many of which leave traces in the skeleton. The fossil evidence of these features suggests that endurance running is a derived capability of the genus Homo, originating about 2 million years ago, and may have been instrumental in the evolution of the human body form.
A General ModelAttributing Structure to Var(y)Estimating Fixed Effects for V KnownEstimating Fixed Effects for V UnknownPredicting Random Effects for V KnownPredicting Random Effects for V UnknownANOVA Estimation of Variance ComponentsMaximum Likelihood (ML) EstimationRestricted Maximum Likelihood (REML)ML or REML?Other Methods for Estimating VariancesAppendixExercises
We report on three epidemiologic studies of orthopedic injuries in exercisers. One group of 438 men and women ran approximately 25 mi per week; 24% reported an injury during the previous year. Higher weekly running mileage and heavier individuals were more likely to report an injury. Injuries were not associated with speed of running, age, gender, type of surface, time of day, or stretching habit. In a second study, rates of injury for the foot, knee, hip, back, shoulder, and elbow were examined in runner (n =2,102) and nonrunner (n =724) patients at a preventive medicine clinic. Only knee injury rates were significantly higher in runners. Third, participants (n=968) in worksite-sponsored exercise programs were evaluated for orthopedic injuries. Rates of exercise injuries were relatively low (net rate = 12%/year in exercisers). Risk of injury in participants starting a walking, running, or jogging program was associated (p <.05) with age, sex, body mass index, flexibility, cardiorespiratory endurance, and number of sit-ups in 1-min.
Using a survey questionnaire design, we investigated the incidence, site, and nature of jogging injuries among all participants of a popular 16 km race. The response rate was 83.6%. Of 4,358 male joggers, 45.8% had sustained jogging injuries during the 1 year study period, 14.2% had required medical care, and 2.3% had missed work because of jogging injuries. Occur rence of jogging injuries was independently associated with higher weekly mileage (P < 0.001), history of previous running injuries (P < 0.001), and competitive training motivation (P = 0.03). Higher mileage was also associated with more frequent medical consultations due entirely to jogging-related injuries. In 33 to 44 year olds (N = 1,757), the number of years of running was inversely related to incidence of injuries (P = 0.02). Injuries were not significantly related to race running speed, training surface, characteristics of running shoes, or relative weight. Achillodynia and calf muscle symptoms were the two most common overuse injuries and occurred significantly more often among older run ners with increased weekly mileage. We conclude that jogging injuries are frequent, that the number of firmly established etiologic factors is low, and that, in recom mending jogging, moderation should be the watchword.
Impact forces have been associated with the development of musculoskeletal injuries. However, results of epidemiologic studies that assess the association between impact loading and the development of acute or chronic injuries do not support this notion. There is agreement that excessive impact force may produce damage to the human musculoskeletal system and that there is a window of loading in which biologic tissue reacts positively to the applied impact load. However, it seems that the impact forces and stresses acting on cartilage, bones, ligaments, and tendons during running are typically within an acceptable range. Running on soft or hard surface materials creates different feelings of comfort. A muscle-tuning model suggests that muscles in general attempt to avoid vibrations using a tuning strategy to establish a critically damped mechanical system. Thus, the different feeling may manifest itself in the form of changed comfort or performance, a concept that is certainly not in agreement with the previous paradigm of impact forces and cushioning.
(C) Lippincott-Raven Publishers.
Overuse soft-tissue injuries occur frequently in runners. Stretching exercises, modification of training schedules, and the use of protective devices such as braces and insoles are often advocated for prevention. This is an update of a review first published in 2001.
To assess the effects of interventions for preventing lower limb soft-tissue running injuries.
We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (March 2011); The Cochrane Library 2010, Issue 4; MEDLINE (1966 to January 2011); EMBASE (1980 to January 2011); and international trial registries (17 January 2011).
Randomised or quasi-randomised trials evaluating interventions to prevent lower limb soft-tissue running injuries.
Two authors independently assessed risk of bias (relating to sequence generation, allocation concealment, blinding, incomplete outcome data) and extracted data. Data were adjusted for clustering if necessary and pooled using the fixed-effect model when appropriate.
We included 25 trials (30,252 participants). Participants were military recruits (19 trials), runners from the general population (three trials), soccer referees (one trial), and prisoners (two trials). The interventions tested in the included trials fell into four main preventive strategies: exercises, modification of training schedules, use of orthoses, and footwear and socks. All 25 included trials were judged as 'unclear' or 'high' risk of bias for at least one of the four domains listed above.We found no evidence that stretching reduces lower limb soft-tissue injuries (6 trials; 5130 participants; risk ratio [RR] 0.85, 95% confidence interval [95% CI] 0.65 to 1.12). As with all non-significant results, this is compatible with either a reduction or an increase in soft-tissue injuries. We found no evidence to support a training regimen of conditioning exercises to improve strength, flexibility and coordination (one trial; 1020 participants; RR 1.20, 95% CI 0.77 to 1.87).We found no evidence that a longer, more gradual increase in training reduces injuries in novice runners (one trial; 486 participants; RR 1.02, 95% CI 0.72 to 1.45). There was some evidence from a poor quality trial that additional training resulted in a significant increase in the number of naval recruits with shin splints (one trial; 1670 participants; RR 2.02, 95% CI 1.11 to 3.70). There was limited evidence that injuries were less frequent in prisoners when running duration (one trial; 69 participants; RR 0.41, 95% CI 0.21 to 0.79) or frequency (one trial; 58 participants; RR 0.19, 95% CI 0.06 to 0.66) were reduced.Patellofemoral braces appear to be effective for preventing anterior knee pain (two trials; 227 participants; RR 0.41, 95% CI 0.24 to 0.67).Custom-made biomechanical insoles may be more effective than no insoles for reducing shin splints (medial tibial stress syndrome) in military recruits (one trial; 146 participants; RR 0.24, 95% CI 0.08 to 0.69).We found no evidence in military recruits that wearing running shoes based on foot shape, rather than standard running shoes, significantly reduced rate of running injuries (2 trials; 5795 participants; Rate Ratio 1.03, 95% CI 0.93 to 1.14).
Overall, the evidence base for the effectiveness of interventions to reduce soft-tissue injury after intensive running is very weak, with few trials at low risk of bias. More well-designed and reported RCTs are needed that test interventions in recreational and competitive runners.
This book provides a comprehensive treatment on modeling approaches for non-Gaussian repeated measures, possibly subject to incompleteness. The authors begin with models for the full marginal distribution of the outcome vector. This allows model fitting to be based on maximum likelihood principles, immediately implying inferential tools for all parameters in the models. At the same time, they formulate computationally less complex alternatives, including generalized estimating equations and pseudo-likelihood methods. They then briefly introduce conditional models and move on to the random-effects family, encompassing the beta-binomial model, the probit model and, in particular the generalized linear mixed model. Several frequently used procedures for model fitting are discussed and differences between marginal models and random-effects models are given attention.
The authors consider a variety of extensions, such as models for multivariate longitudinal measurements, random-effects models with serial correlation, and mixed models with non-Gaussian random effects. They sketch the general principles for how to deal with the commonly encountered issue of incomplete longitudinal data. The authors critique frequently used methods and propose flexible and broadly valid methods instead, and conclude with key concepts of sensitivity analysis.
Without putting too much emphasis on software, the book shows how the different approaches can be implemented within the SAS software package. The text is organized so that the reader can skip the software-oriented chapters and sections without breaking the logical flow.
Lower limb overuse injuries are common among people who are exposed to physical stress. Orthotic shoe insoles are widely used to prevent lower limb overuse injuries. Here, we conducted a randomized-controlled study to examine whether the use of orthotic insoles prevents lower limb overuse injuries. Participants (n=228) were randomly assigned to use (n=73) or not to use (n=147) orthotic insoles. The insoles were molded to the shape of the foot to provide support during physical activity. The main outcome measure in the present study was the physician-diagnosed lower limb overuse injury. Thirty-four (46.6%) subjects in the insole group were diagnosed with a lower limb overuse injury compared with 56 (38.1%) in the control group (P=0.29) during the 6-month study period. When body mass index and the results of a 12-min running test and muscle strength were adjusted in a Cox's regression model, the hazard ratio for lower limb overuse injury in the insole group was 1.3 (95% confidence intervals: 0.8-2.1) compared with the control group. Use of orthotic insoles was not associated with a decrease in lower limb overuse injuries. Our findings suggest that routine use of orthotic insoles does not prevent physical-stress-related lower limb injuries in healthy young male adults.
To determine the effect of modern-day running shoes on lower extremity joint torques during running.
Two-condition experimental comparison.
A 3-dimensional motion analysis laboratory.
A total of 68 healthy young adult runners (37 women) who typically run in running shoes.
All subjects ran barefoot and in the same type of stability running footwear at a controlled running speed. Three-dimensional motion capture data were collected in synchrony with ground reaction force data from an instrumented treadmill for each of the 2 conditions.
Peak 3-dimensional external joint torques at the hip, knee, and ankle as calculated through a full inverse dynamic model.
Increased joint torques at the hip, knee, and ankle were observed with running shoes compared with running barefoot. Disproportionately large increases were observed in the hip internal rotation torque and in the knee flexion and knee varus torques. An average 54% increase in the hip internal rotation torque, a 36% increase in knee flexion torque, and a 38% increase in knee varus torque were measured when running in running shoes compared with barefoot.
The findings at the knee suggest relatively greater pressures at anatomical sites that are typically more prone to knee osteoarthritis, the medial and patellofemoral compartments. It is important to note the limitations of these findings and of current 3-dimensional gait analysis in general, that only resultant joint torques were assessed. It is unknown to what extent actual joint contact forces could be affected by compliance that a shoe might provide, a potentially valuable design characteristic that may offset the observed increases in joint torques.
The popularity of running is still growing. As participation increases, running-related injuries also increase. Until now, little is known about the predictors for injuries in novice runners.
Predictors for running-related injuries (RRIs) will differ between male and female novice runners.
Cohort study; Level of evidence, 2.
Participants were 532 novice runners (226 men, 306 women) preparing for a recreational 4-mile (6.7-km) running event. After completing a baseline questionnaire and undergoing an orthopaedic examination, they were followed during the training period of 13 weeks. An RRI was defined as any self-reported running-related musculoskeletal pain of the lower extremity or back causing a restriction of running for at least 1 week.
Twenty-one percent of the novice runners had at least one RRI during follow-up. The multivariate adjusted Cox regression model for male participants showed that body mass index (BMI) (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.05-1.26), previous injury in the past year (HR, 2.7; 95% CI, 1.36-5.55), and previous participation in sports without axial load (HR, 2.05; 95% CI, 1.03-4.11) were associated with RRI. In female participants, only navicular drop (HR, 0.85; 95% CI, 0.75-0.97) remained a significant predictor for RRI in the multivariate Cox regression modeling. Type A behavior and range of motion (ROM) of the hip and ankle did not affect risk.
Male and female novice runners have different risk profiles. Higher BMI, previous injury, and previous sports participation without axial loading are important predictors for RRI in male participants. Further research is needed to detect more predictors for female novice runners.
To compare selected structural and biomechanical factors between female runners with a history of plantar fasciitis and healthy control subjects.
Cross-sectional.
University of Delaware Motion Analysis Laboratory, Newark, Delaware; and University of Massachusetts Biomechanics Laboratory, Amherst, Massachusetts.
Twenty-five female runners with a history of plantar fasciitis were recruited for this study. A group of 25 age- and mileage-matched runners with no history of plantar fasciitis served as control subjects.
The independent variable was whether or not subjects had a history of plantar fasciitis.
Subjects ran overground while kinematic and kinetic data were recorded using a motion capture system and force plate. Rearfoot kinematic variables of interest included peak dorsiflexion, peak eversion, time to peak eversion along with eversion excursion. Vertical ground reaction force variables included impact peak and the maximum instantaneous load rate. Structural measures were taken for calcaneal valgus and arch index during standing and passive ankle dorsiflexion range of motion.
A significantly greater maximum instantaneous load rate was found in the plantar fasciitis group along with an increased ankle dorsiflexion range of motion compared with the control group. The plantar fasciitis group had a lower arch index compared with control subjects, but calcaneal valgus was similar between groups. No differences in rearfoot kinematics were found between groups.
These data indicate that a history of plantar fasciitis in runners may be associated with greater vertical ground reaction force load rates and a lower medial longitudinal arch of the foot.
The first aim of this study was to assess how changes in the mechanical characteristics of the foot/shoe-ground interface affect spatio-temporal variables, ground pressure distribution, sagittal plane kinematics, and running economy in 8 experienced barefoot runners. The second aim was to assess if a special lightweight shoe (Vibram Fivefingers) was effective in mimic the experience of barefoot running.
By using an instrumented treadmill, barefoot running, running with the Fivefingers, and running with standard running shoe were compared, analyzing a large numbers of consecutive steps. Foot/shoe-ground interface pressure distribution, lower limb kinematics, V.O(2) and heart rate data were simultaneously collected.
Compared to the standard shod condition when running barefoot the athletes landed in more plantarflexion at the ankle. This caused reduced impact forces and changes in stride kinematics. In particular, significantly shorter stride length and contact times and higher stride frequency were observed (P<0.05). Compared to standard shod condition, V.O(2) and peak impact forces were significantly lower with Fivefingers (P<0.05) and much closer to barefoot running. Lower limb kinematics with Fivefingers was similar to barefoot running with a foot position which was significantly more plantarflexed than in control shoe (P<0.05).
The data of this study support the assumption that changes in the foot-ground interface led to changes in running pattern in a group of experienced barefoot runners. The Fivefingers model seems to be effective in imitating the barefoot conditions while providing a small amount of protection.