Article

Greater vertical impact loading in female runners with medically diagnosed injuries: A prospective investigation

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Abstract

Background Running has been critical to human survival. Therefore, the high rate of injuries experienced by modern day runners is puzzling. Landing on the heel, as most modern day shod runners do, results in a distinct vertical impact force that has been shown to be associated with running-related injuries. However, these injury studies were retrospective in nature and do not establish cause and effect. Objective To determine whether runners with high impacts are at greater risk for developing medically diagnosed injuries. Methods 249 female runners underwent a gait analysis to measure vertical instantaneous loading rate, vertical average loading rate (VALR), vertical impact peak (VIP) and peak vertical force. Participants then recorded their mileage and any running-related injuries monthly in a web-based, database programme. Variables were first compared between the entire injured (INJ; n=144) and uninjured (n=105) groups. However, the focus of this study was on those injured runners seeking medical attention (n=103) and those who had never injured (n=21). Results There were no differences between the entire group of injured and uninjured groups. However, all impact-related variables were higher in those with medically diagnosed injuries compared with those who had never been injured. (effect size (ES) 0.4–0.59). When VALR was >66.0 body weight (BW)/s, the odds of being DX_INJ were 2.72 (95% CI 1.0 to 7.4). Impact loading was associated with bony and soft-tissue injuries. Conclusions Vertical average loading rate was lower in female runners classified as ‘never injured’ compared with those who had been injured and sought medical attention.

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... It is no surprise that researchers are calling for more biomechanical studies involving gait kinetics in relation to shoe cushioning [18] and based on gender [40], as female runners are at an increased risk of running-related injuries compared to their male counterparts [7,41,42], have slightly different patterns of gait [40], and present greater shock attenuation than males [43]. This could mean either lower tolerance to peak impact forces or they are experiencing greater forces on impact and may respond differently to different shoe conditions based on gait and anatomy [19,39,44,45]. ...
... The collision between foot and ground during fast walking or running generates a shockwave of energy on every step, necessitating passive attenuation processes to protect vital systems [3][4][5][6]. Both activities face challenges as these passive processes are highly sensitive to factors such as impact force magnitude, loading rate, and repetition [7,8]. All of these are exacerbated at faster paces, particularly at speeds >12 km·h −1 , which involve increases in stride length and/or stride frequency [9][10][11][12][13][14]. ...
... Additionally (Figure 3), higher speeds resulted in increases in peak vertical impact, average loading rate, and active vertical peak force, along with a decreased time to active vertical peak force [9,11,13,56]. These kinetic variables have also been associated with running-related injuries [5,7], implicating running speed as a factor in injury aetiology [57]. ...
Article
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The purpose of this study was to compare the mechanical properties of a non-cushioned minimalistic shoe and cushioned shoe during walking at 6 and running at 10 and 14 km∙h−1 in habituated female runners. Twelve habituated female runners completed two trials (cushioned shoe vs. minimalist shoe) with three within-trial speeds (6, 10, and 14 km∙h−1) in a counter-balanced design. Flexible pressure insole sensors were used to determine kinetic variables (peak vertical impact force, average loading rate, active vertical peak force, time to active peak vertical force, and impulse) and spatiotemporal variables (stride duration, cadence, ground contact time, swing time, and time to midstance). Cushioned running shoes exhibited greater energy absorption (690%), recovered energy (920%), and heat dissipation (350%). The cushioned shoes significantly reduced peak vertical impact (~12%) and average loading rate (~11%) at running speeds 10–14 km∙h−1. However, these effects were not observed during walking, nor did the cushioned shoes influence peak active force, impulse, stride duration, ground contact or swing time. Cushioned running shoes provide significant benefits in energy absorption, energy recovery, and heat dissipation, which decrease impact-related forces and loading rates in female runners without changing the spatiotemporal variables of gait.
... The incidence of lower-extremity injuries during running ranges from 20% to 79% [3,4], with the most common injuries arising at the knee and below [3,5]. Impact loading variables, such as vertical ground reaction forces (GRFs) or shank acceleration peak measured with wearable sensors, have been associated with running injuries [6][7][8][9]. Vertical loading rates describe the increase in the vertical GRF during the stance phase. The vertical loading rate refers to the vertical average loading rate (VALR) or the vertical instantaneous loading rate (VILR). ...
... 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]. ...
... There is inconclusive evidence that higher impact loading amplitude is associated with running injuries [13]. Indeed, some prospective and retrospective studies have found a positive relationship between loading rate amplitude and running injuries [6,21,35,36]. However, other prospective or retrospective studies have found no association between impact loading and running injuries [37][38][39]. ...
Article
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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.
... 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). ...
... 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). Another study of 300 runners observed that greater knee stiffness was a significant predictor of injury (Messier et al., 2018). ...
... The role of AVLR in running-related musculoskeletal injury risk remains controversial. Some studies demonstrate an association between high AVLR and injury (Bredeweg et al., 2013b;Davis et al., 2016;Johnson et al., 2020;Milner et al., 2006;van der Worp et al., 2016;Zadpoor and Nikooyan, 2011), while others observe no relationship (Dudley et al., 2017;Kliethermes et al., 2021;Napier et al., 2018). In this study, there was no group-by-time interaction for AVLR, suggesting that the telehealth gait retraining intervention did not differentially impact AVLR across groups. ...
... However, running increases the risk of musculoskeletal injuries, and it is necessary to understand the cause of these injuries in order to prevent them effectively [100]. One of the essential roles of the human musculoskeletal system is to attenuate and disperse shock waves created by foot contact with the ground [96]. ...
... The American Medical Association (AMA) described shin splints in The Standard Nomenclature of Athletic Injuries as "pain and discomfort in the leg from recurrent jogging on hard surfaces or forcible, excessive use of the foot flexors." "A more accurate word that explains the inflammatory traction event in the tibial aspect of the common leg in runners is the medial periostitis of the tibial traction or simply the medial tibial periostitis" [96]. A malfunction of the anterior and posterior tibialis is frequently involved, and the attachment of these muscles might be the source of pain. ...
... Running, on the other hand, is associated with an increased risk of musculoskeletal injuries, and it is essential to have an understanding of the factors that lead to these injuries in order to successfully prevent them [112]. Shock waves are generated whenever a person's foot makes contact with the ground [96]. One of the primary functions of the human musculoskeletal system is to dampen and spread out these shock waves. ...
Thesis
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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
... For this reason, several studies have sought to determine the aetiological factors of RRIs. Several risk factors have been proposed to relate to RRIs, with sex [2,6], age [7,8], impact loading [9,10], running technique [11,12], training behaviour [8,13] and previous history of injury [8,14] all thought to be influential. Thus, it is critical to examine all factors and how their combined interaction may impact the occurrence of prospective RRIs. ...
... Thirdly, while it is well recognised that aetiological factors appear to be multifactorial in nature [4,21], studies have focused on specific risk factors in isolation (e.g. impact loading only) [9,22], or have concentrated on limited segments of the kinematic chain [2], which may overlook the interdependent contributions of various segments such as the pelvis or trunk to prospective injury. It is important to consider multiple aspects of internal load (e.g. ...
... Although the precision of impact loading and kinematic motion analysis is strongest within a laboratory, the recent implementation of inertial measurement units for impact loading analysis should facilitate the examination of more representative strides, while also allowing a more insightful examination of segmental loading with simultaneous kinematic analysis. Lastly, the conflicting definitions of injury amongst the prospective RRI research has made comparisons between studies challenging, with none of the aforementioned prospective studies utilizing a consensus-based definition of RRI to date [2,9,22]. ...
Article
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Background Running-related injuries (RRIs) are a prevalent issue for runners, with several factors proposed to be causative. The majority of studies to date are limited by retrospective study design, small sample sizes and seem to focus on individual risk factors in isolation. This study aims to investigate the multifactorial contribution of risk factors to prospective RRIs. Methods Recreational runners (n = 258) participated in the study, where injury history and training practices, impact acceleration, and running kinematics were assessed at a baseline testing session. Prospective injuries were tracked for one year. Univariate and multivariate Cox regression was performed in the analysis. Results A total of 51% of runners sustained a prospective injury, with the calf most commonly affected. Univariate analysis found previous history of injury < 1 year ago, training for a marathon, frequent changing of shoes (every 0–3 months), and running technique (non-rearfoot strike pattern, less knee valgus, greater knee rotation) to be significantly associated with injury. The multivariate analysis revealed previous injury, training for a marathon, less knee valgus, and greater thorax drop to the contralateral side to be risk factors for injury. Conclusion This study found several factors to be potentially causative of injury. With the omission of previous injury history, the risk factors (footwear, marathon training and running kinematics) identified in this study may be easily modifiable, and therefore could inform injury prevention strategies. This is the first study to find foot strike pattern and trunk kinematics to relate to prospective injury.
... vertical instantaneous loading rate (VILR). Briefly, peak braking and vertical force were the maximum forces in the posterior and upward directions, respectively; VIP was the local maximum within the first 50 ms following initial contact; and loading rates were calculated between 20% and 80% of the time period from initial contact to VIP where VALR was the slope for the entire region and VILR was the steepest slope from successive data points within the region (Adams et al., 2018; I. S. Davis et al., 2016;Napier et al., 2018). We removed outliers for continuous variables if the value was more than 2.2 times the interquartile range above or below the first or third quartiles, respectively (Hoaglin & Iglewicz, 1987) and performed mixed model multiple linear regressions in RStudio (v.1.2, ...
... Additionally, the lack of neuromuscular maturation, sport-specific instruction, and experience may also contribute poorer motor coordination demonstrated by pre-and mid-pubertal athletes (Freitas et al., 2016). While higher loading rates did not increase the risk of sustaining an injury for adult runners (Kliethermes et al., 2021;Schmida et al., 2022), adults runners who developed an RRI experienced higher loading rates than those who remained injury-free (Bredeweg et al., 2013; I. S. Davis et al., 2016). It is unknown if loading rates influence injury risk for adolescent runners and there is no consistent evidence that age influences injury risk for adolescent runners (Krabak et al., 2021). ...
... ation and having a lower preferred cadence or longer preferred step length does not guarantee a runner will experience large braking and/or vertical forces. Second, we are unable to make conclusions about injury risk due to the cross-sectional design of our study. Although higher GRFs have been associated with RRIs in adults (Bredeweg et al., 2013;I. S. Davis et al., 2016;Malisoux et al., 2022;Napier et al., 2018), it is unknown if GRFs are associated with RRIs in adolescent runners. Prospective research in adolescent runners is needed to better understand the interaction between GRFs and injury rates, as well as the efficacy of cadence manipulation and/or neuromuscular training on reducing RRIs. ...
Article
For adults, increasing cadence reduces ground reaction forces, but a lower preferred cadence does not predispose adults to experience higher ground reaction forces. Pubertal growth and motor control changes influence running mechanics, but it is unknown if preferred cadence or step length are associated with ground reaction forces for pre-adolescent and adolescent runners. Pre-adolescent and adolescent runners underwent an overground running analysis at a self-selected speed. Mixed model multiple linear regressions investigated the associations of preferred cadence, step length, physical maturation, and sex on ground reaction forces, while accounting for running speed and leg length. Running with a lower preferred cadence or longer preferred step length was associated with larger peak braking and vertical forces (p ≤ .01), being less physically mature was associated with larger vertical impact peak force and vertical loading rate (p ≤ .01), and being a male was associated with larger loading rates (p ≤ .01). A lower preferred cadence or longer preferred step length were associated with higher braking and vertical forces and being less physically mature or a male were associated with higher loading rates. An intervention to increase cadence/decrease step length could be considered if ground reaction forces are a concern for an adolescent runner.
... We calculated discrete temporal-spatial parameters including running speed (m/s), cadence (steps/min), step length (m), step width (cm), and stance duration (s) from the IC and TO events using the Automatic Gait Detection pipeline in Visual3D. We normalised kinetic data to the participant's body mass and calculated discrete GRF variables including peak braking force (N·kg −1 ), peaking vertical force (N·kg −1 ), vertical impact peak (VIP; local maximum within the first 50 ms after IC (Davis et al., 2016), vertical average loading rate (VALR, N·kg −1 ·s −1 ), vertical instantaneous loading rate (VILR, N·kg −1 ·s −1 ), and braking impulse (N·kg −1 ·s −1 ). We calculated vertical loading rates between 20% and 80% from initial contact to the VIP, where the VALR is the slope for the entire region and the VILR is the steepest slope from successive data points within the region (Davis et al., 2016;Heiderscheit et al., 2011). ...
... We normalised kinetic data to the participant's body mass and calculated discrete GRF variables including peak braking force (N·kg −1 ), peaking vertical force (N·kg −1 ), vertical impact peak (VIP; local maximum within the first 50 ms after IC (Davis et al., 2016), vertical average loading rate (VALR, N·kg −1 ·s −1 ), vertical instantaneous loading rate (VILR, N·kg −1 ·s −1 ), and braking impulse (N·kg −1 ·s −1 ). We calculated vertical loading rates between 20% and 80% from initial contact to the VIP, where the VALR is the slope for the entire region and the VILR is the steepest slope from successive data points within the region (Davis et al., 2016;Heiderscheit et al., 2011). ...
Article
Increasing cadence is an intervention to reduce injury risk for adolescent long-distance runners. It is unknown how adolescents respond biomechanically when running with a higher than preferred cadence. We examined the influence of increasing cadence on peak joint angles, moments and powers, and ground reaction forces in long-distance runners. We collected three-dimensional kinematics and kinetics for 31 high school cross-country runners during overground running at their preferred cadence (baseline), +5%, and +10% baseline cadence. We performed repeated-measures ANOVAs to compare peak joint angles, moments and powers, and ground reactions forces among cadence conditions. Increasing cadence reduced peak pelvis, hip, knee, and ankle joint angles (p ≤ .01), peak knee moment and powers (p < .001), peak ankle power (p ≤ .01), and peak ground reaction forces (p ≤ .01) but increased peak hip moment and powers (p < .001). Increasing cadence by 10% elicited greater magnitude changes compared to increasing cadence by 5%. Increasing cadence may be a beneficial intervention to reduce lower extremity peak joint angles and knee kinetics for adolescent long-distance runners. The increase in hip kinetics when running at a higher than preferred cadence indicates this intervention increases the loads applied to the hip for adolescent long-distance runners.
... Higher vertical GRF may be considered an inevitable result of needing a higher percentage of available strength to propel the body towards toeoff (Cavanagh and Kram, 1989). Female runners exhibited a greater peak vertical impact force at faster running speeds, which may induce potential shock increases in the musculoskeletal system and thus lead to running-related injuries (Davis et al., 2016;Vannatta et al., 2020). This may provide a potential explanation for the higher patellofemoral pain and tibial stress fracture rates among female runners (Wright et al., 2015;Almonroeder and Benson, 2017). ...
... Additionally, male runners exhibited increased braking force at higher speeds, suggesting greater impact during the braking phase of high-speed running, aligning with previous findings (Hollis et al., 2019). The runner-ground interaction during the braking phase is crucial, playing a significant role in lower extremity injury risk (Davis et al., 2016;Williams et al., 2020;Jiang et al., 2021). At initial ground contact, the lower extremity experiences rapid loading with forces exceeding 1.5 times the runner's body weight (Grabowski and Kram, 2008;Logan et al., 2010). ...
Article
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Introduction: The biomechanics associated with human running are affected by gender and speed. Knowledge regarding ground reaction force (GRF) at various running speeds is pivotal for the prevention of injuries related to running. This study aimed to investigate the gait pattern differences between males and females while running at different speeds, and to verify the relationship between GRFs and running speed among both males and females. Methods: GRF data were collected from forty-eight participants (thirty male runners and eighteen female runners) while running on an overground runway at seven discrete speeds: 10, 11, 12, 13, 14, 15 and 16 km/h. Results: The ANOVA results showed that running speed had a significant effect (p < 0.05) on GRFs, propulsive and vertical forces increased with increasing speed. An independent t-test also showed significant differences (p < 0.05) in vertical and anterior-posterior GRFs at all running speeds, specifically, female runners demonstrated higher propulsive and vertical forces than males during the late stance phase of running. Pearson correlation and stepwise multiple linear regression showed significant correlations between running speed and the GRF variables. Discussion: These findings suggest that female runners require more effort to keep the same speed as male runners. This study may provide valuable insights into the underlying biomechanical factors of the movement patterns at GRFs during running.
... Footstrike pattern can be evaluated kinematically by measurement of footstrike angle (FSA) (Altman & Davis, 2012), which is the angle between the foot and the running surface in the sagittal plane at initial contact. Impact loading is usually quantified by vertical average loading rate (VALR) and vertical instantaneous loading rate (VILR), which are the average and maximum slopes of the line through the 20% to the 80% point of the vertical impact peak, respectively (Davis et al., 2016). Previous studies have suggested an interaction effect of running surface (i.e., level, uphill and downhill running) on both footstrike pattern and vertical loading rates (de Almeida et al., 2015;Johnson & Davis, 2022). ...
... Additionally, our findings indicate that trail runners may experience greater impact loading. It has been reported that the viscoelastic structures of the musculoskeletal system do not respond well to these impulsive loads (Davis et al., 2016). A previous large scale randomised control trial has reported a causal relationship between high impact loading and running-related injuries (Chan et al., 2018). ...
... Although rate of impact, a surrogate for loading rate, was not associated with injury risk, accelerometry data from an on-shoe sensor may not be sufficient to accurately estimate loading rate, 46 suggesting that our results should be interpreted with caution. Kinetic variables, such as a greater vertical impact peak, 9 AVLR,9,27,53 and peak braking force, 44 may have a role in RRI development. However, in a recent prospective study following .800 ...
Article
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Background Running biomechanics have been linked to the development of running-related injuries in recreational and military runners. Purpose/Hypothesis The purpose of this study was to determine if personal characteristics or running biomechanical variables are associated with running-related injury incidence or time to injury in military cadets undergoing training. It was hypothesized that a rearfoot strike pattern, greater rate of impact, or a lower step rate would be related to a greater running-related injury incidence and a decreased time to injury. Study Design Cohort study; Level of evidence, 2. Methods Military cadets wore an on-shoe wearable sensor that analyzed biomechanical variables of foot strike pattern, rate of impact, running pace, step rate, step length, and contact time during cadet basic training (60 days). Running-related injuries during cadet basic training were determined by medical record review. Personal and running variables between the injured and uninjured cadets were compared using independent t tests and chi-square analyses. Time to injury and hazard ratios (HRs) were estimated using Kaplan-Meier survival curves and Cox proportional hazard regression models, respectively. Results Of the 674 cadets who completed the study, 11% sustained a running-related injury. A significantly greater proportion of the injured participants were female (χ ² = 7.95; P = .005) and had a prior history of injury (χ ² = 7.36; P = .007). Univariate Cox proportional hazard regression models revealed greater injury risk in females (HR, 1.96; 95% CI, 1.22-3.16; P = .005) and cadets with a prior injury history (HR, 1.86; 95% CI, 1.18-2.93; P = .008). After adjusting Cox models for prior injury, females were found to be at a 1.89 times (95% CI, 1.17-3.04; P = .009) greater risk of injury. Running biomechanical variables were not associated with injury risk. Conclusion Study results indicated that non-modifiable risk factors such as female sex and prior injury history increased the risk of running-related injury in cadets undergoing military training. Running biomechanical variables measured by the wearable sensor were not associated with injury in this study.
... Moreover, insights into biomechanical adaptations post-injury facilitate evidence-based decision-making and promote safe return-to-sport protocols. 21 ...
Article
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Motion capture technology has become integral in studying gait patterns among runners to understand their implications for injury risks. This review synthesizes current literature to examine methodologies and findings related to using motion capture technology for gait analysis in runners. A systematic search was conducted across major academic databases to identify relevant studies published in peer-reviewed journals and conference proceedings. Inclusion criteria focused on studies utilizing motion capture technology to assess biomechanical factors associated with running-related injuries.The review highlights key biomechanical parameters analyzed through motion capture, including joint angles, forces, and muscle activations during running. Studies consistently report on the relationship between gait abnormalities and various injuries such as stress fractures, patellofemoral pain syndrome, and Achilles tendonitis. Practical implications for injury prevention strategies are discussed including personalized gait assessments, targeted interventions such as gait retraining, and advancements in footwear design aimed at optimizing running mechanics and reducing injury risks. Motion capture technology offers a robust platform for advancing our understanding of gait mechanics in runners and their impact on injury prevention. Future research directions should focus on standardizing methodologies, integrating multi-modal data, and applying findings to enhance clinical practice and athletic performance.
... Higher active peaks have been associated with an increased risk of RRIs, for example, a stress fracture (Popp et al., 2017;Grimston et al., 1991;Kliethermes et al., 2021), patellofemoral pain (Messier et al., 1991), and ankle instability (Bigouette et al., 2016). While some studies (Messier et al., 2018;Bredeweg et al., 2013;Davis et al., 2016) observed no differences in the impact peak between injured and non-injured runners, undergoing a gait-retraining program targeting the reduction of the impact peak (Chan et al., 2018) has shown to reduce a runner's chance of sustaining an injury. The differences in ground contact time among injured and noninjured male novice runners (Bredeweg et al., 2013) and the association between vGRF impulse and bone stress injuries (Kliethermes et al., 2021), further indicate the importance of vGRF characteristics in assessing the risk of RRIs. ...
Article
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Running poses a high risk of developing running-related injuries (RRIs). The majority of RRIs are the result of an imbalance between cumulative musculoskeletal load and load capacity. A general estimate of whole-body biomechanical load can be inferred from ground reaction forces (GRFs). Unfortunately, GRFs typically can only be measured in a controlled environment, which hinders its wider applicability. The advent of portable sensors has enabled training machine-learned models that are able to monitor GRF characteristics associated with RRIs in a broader range of contexts. Our study presents and evaluates a machine-learning method to predict the contact time, active peak, impact peak, and impulse of the vertical GRF during running from three-dimensional sacral acceleration. The developed models for predicting active peak, impact peak, impulse, and contact time demonstrated a root-mean-squared error of 0.080 body weight (BW), 0.198 BW, 0.0073 BW ⋅ seconds, and 0.0101 seconds, respectively. Our proposed method outperformed a mean-prediction baseline and two established methods from the literature. The results indicate the potential utility of this approach as a valuable tool for monitoring selected factors related to running-related injuries.
... Different solutions of shoe cushioning have been developed to attenuate impact peak forces and loading rate, as these biomechanical characteristics are associated with the development of specific running injuries. 18 The shock absorption properties of footwear mainly result from the materials used in the sole (ie, their type, density, structure and combinations thereof), as well as from the geometry of the shoe (ie, the midsole thickness and the design of inserts). Only a few prospective studies have investigated the impact of shoe cushioning on injury risk in running. ...
Article
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Previous work has demonstrated the protective effect of shoe cushioning on injury risk in leisure-time runners, but most models currently available on the market have greater cushioning than those investigated so far. Also, the optimal level of cushioning and the role of cushioning on the forepart of the shoe for injury prevention are still unknown. The main aim of this study is to determine whether (1) current ‘extra soft’ cushioning material at the rear part of the shoe reduces injury risk compared with stiffer material and (2) cushioning under the forepart of the shoe also contributes to injury risk reduction. This randomised trial with a 6-month intervention will involve 1000+ healthy leisure-time runners who will randomly receive one of the three running shoe versions. Study shoe versions will differ in their cushioning properties (ie, stiffness) at the rear or the forepart. Participants will self-report any lower limb or lower back problems on a dedicated electronic system every week, while the system will collect training data from the participant’s sports watch. Time-to-event analyses will be used to compare injury risk between the three study groups and to investigate the association between the runner’s characteristics, cushioning level and position, training and injury risk. The study was approved by the National Ethics Committee for Research (Ref: 202405/02 v2.0), and the protocol has been registered on https://clinicaltrials.gov/ (NCT06384872, 02/08/2024). Outcomes will be disseminated through presentations at international conferences and publications in peer-reviewed journals, popular magazines and specialised websites.
... Impact loading during landing has been associated with acute joint injuries such as anterior cruciate ligament (ACL) tears 3 and chronic overuse injuries such as patellofemoral pain. 4,5 Female athletes are more likely to sustain such injuries compared with their male counterparts, with 41.7% of traumatic injuries occurring to the knee and ankle. 6 Both ankle and knee joint injuries, which result in chronic instability, drastically increase the risk for early development of osteoarthritis (OA). ...
Article
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Purpose To evaluate whether cumulative impact load and serum biomarkers are related to lower-extremity injury and to determine any impact load and cartilage biomarker relationships in collegiate female basketball athletes. Methods This was a prospective longitudinal study evaluating lower-extremity impact load, serum cartilage biomarkers, and injury incidence over the course of a single collegiate women’s basketball season. Data were collected from August 2022 to April 2023; no other follow-up after the cessation of the season was conducted in this cohort. Inclusion criteria for the study included collegiate women’s basketball athletes, ages 18 to 25 years, who were noninjured at the start of the study time frame (August 2024). Cartilage synthesis (procollagen II carboxy propeptide and aggrecan chondroitin sulfate 846 epitope) and degradation (collagen type II cleavage) biomarkers were evaluated at 6 season timepoints. Impact load metrics (cumulative bone stimulus, impact intensity) were collected during practices using inertial measurement units secured to the distal medial tibiae. Injury was defined as restriction of participation for 1 or more days beyond day of initial injury. Cumulative impact load metrics were calculated over the week before any documented injury and blood draws for analysis. Point biserial and Pearson product moment correlations were used to determine the relationship between impact load metrics, serum biomarkers, and injury. Results Eleven collegiate women’s basketball athletes (height: 1.86 meters, mass: 82.0 kg, age: 20.54 years) participated. Greater medium-range (6-20 g) cumulative impact intensities during week 5 and 6 for both limbs (r = 0.674, P = .023) and high-range (20-200 g) during week 8 for both limbs (0.672, P = .024) were associated with injury. Greater cumulative bone stimulus was associated with increased procollagen II carboxy propeptide levels before conference playoffs for right (r = 0.694, P = .026) and left (r = 0.747, P = .013) limbs. Greater chondroitin sulfate 846 epitope levels at off-season-1 (r = 0.729, P = .017), and at the beginning of the competitive season (r = 0.645, P = .044) were associated with season-long injury incidence. Conclusions In this study, we found that moderate-to-high intensity impacts (6-200 g) early in the season were associated with subsequent injury among female collegiate basketball players. Increased cartilage synthesis at various time points was correlated with increased cumulative bone stimulus metrics and season-long injury incidence in this population. Level of Evidence Level IV, prognostic case series.
... Additionally, two side-view cameras were used, with their positions illustrated in Figure 1; they recorded whether the part of the foot that contacted the ground was both the midfoot and forefoot or the rearfoot alone (type of strike). We classified midfoot and forefoot in the same category based on previous studies that included runners with midfoot strike patterns in the forefoot group since the biomechanical aspects of the forefoot strike and midfoot strike closely resemble one another [19]. ...
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(1) Background and objectives: Running-related injuries (RRIs) are commonly attributed to improper running posture and overuse. This study aims to analyze the running motions of individuals with and without RRIs using a sensor-free method, which offers a user-friendly and straightforward approach. (2) Materials and Methods: A total of 155 runners were divided into two groups: the normal runner group (runners who had never been injured, n = 50) and the RRI group (runners who had experience at least one injury while running, n = 105). The forward head posture (FHP), trunk lean, hip rotation, horizontal movement of the center of gravity (COG), vertical movement of the COG, pelvic rotation, hip hike, and type of strike were measured for posture analysis. (3) Results: We found that the left–right balance of the pelvis and the spinal posture during running were associated with RRIs. The difference in hip hike and FHP emerged as key predictors of running-related musculoskeletal injury occurrence from our logistic regression analysis. (4) Conclusions: Identifying pathological movements in runners through running motion analysis without the use of sensors can be instrumental in the prevention and treatment of RRIs.
... When a runner exhibits a non-rearfoot contact position, the vertical momentum is converted into rotational momentum, thus the total mass being decelerated is reduced, leading to a reduction in the magnitude of impact loading experienced by the body [49,50]. Reductions in the loading rate in the footstrike group may have clinical relevance as although tibial stress fracture risk was not significantly reduced and the vertical rate of loading has been shown to be unrepresentative of tibial loading [21], it has been linked to the aetiology of plantar fasciitis [71] and to prospectively differentiate between injured runners from those who had never been injured [72]. As such, although further investigation is certainly required, subsequent intervention trials could consider the efficacy of footstrike modification on other musculoskeletal injuries in runners, beyond those investigated in the current study. ...
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Introduction: The aim of this study was to undertake a randomized control trial examining the effects of a 10-week footstrike transition program on tibial stress fracture risk compared to control. Material and methods: Twenty habitual rearfoot strike runners were randomly assigned to either footstrike or control groups. The footstrike group undertook a graduated 10-week program which allowed them to convert their habitual rearfoot strike pattern, whereas the control group maintained normal training regime without any alterations to their strike pattern. Running biomechanics were collected using an eight-camera motion capture system and ground reaction forces using a force plate. Tibial strains were quantified using finite element modelling and stress fracture probability calculated via probabilistic modelling over 100 days of running. The primary outcome tibial stress fracture probability, and secondary outcomes running biomechanics, muscle forces, joint contact forces, and tibial strain indices; were measured at baseline and 10-weeks. Results: Intention-to-treat analyses revealed no significant alterations in the primary outcome (Footstrike: baseline = 12.82% & 10-weeks = 10.82%, Control: baseline = 15.43% & 10-weeks = 13.39%) between arms. However, alterations in the strike index (Footstrike: baseline = 21.79% & 10-weeks = 65.74%, Control: baseline = 13.61% & 10-weeks = 12.41%) and the loading rate (Footstrike: baseline = 165.85BW/s & 10-weeks = 100.01 BW/s, Control: baseline = 170.13 BW/s & 10-weeks = 197.87 BW/s) were significantly greater in the footstike group compared to control. Conclusion: This trial concludes that the footstrike intervention adopted in this study was not effective in mediating improvements tibial stress fracture risk, although future intervention trials could examine the efficacy of footstrike modification on other musculoskeletal injuries in runners.
... Cohort 2. The inclusion criteria for Cohort 2 were designed to construct a more homogenous and specialized population of runners to assess the generalizability of in-lab data to a new population of athletes. One such specialized population often studied in prospective research on running injuries is young adult female runners, who may be at greater risk of overuse injury (e.g., Davis et al., Rauh et al. [15,16]). In service of this goal of testing the generalizability of findings from the in-lab data, Cohort 2 included women aged 18-32 were recruited who fulfilled the same inclusion criteria as Cohort 1 (running at least three times per week with one run lasting at least 40 min, and no current injuries or contraindications for exercise). ...
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Biomechanical assessments of running typically take place inside motion capture laboratories. However, it is unclear whether data from these in-lab gait assessments are representative of gait during real-world running. This study sought to test how well real-world gait patterns are represented by in-lab gait data in two cohorts of runners equipped with consumer-grade wearable sensors measuring speed, step length, vertical oscillation, stance time, and leg stiffness. Cohort 1 (N = 49) completed an in-lab treadmill run plus five real-world runs of self-selected distances on self-selected courses. Cohort 2 (N = 19) completed a 2.4 km outdoor run on a known course plus five real-world runs of self-selected distances on self-selected courses. The degree to which in-lab gait reflected real-world gait was quantified using univariate overlap and multivariate depth overlap statistics, both for all real-world running and for real-world running on flat, straight segments only. When comparing in-lab and real-world data from the same subject, univariate overlap ranged from 65.7% (leg stiffness) to 95.2% (speed). When considering all gait metrics together, only 32.5% of real-world data were well-represented by in-lab data from the same subject. Pooling in-lab gait data across multiple subjects led to greater distributional overlap between in-lab and real-world data (depth overlap 89.3–90.3%) due to the broader variability in gait seen across (as opposed to within) subjects. Stratifying real-world running to only include flat, straight segments did not meaningfully increase the overlap between in-lab and real-world running (changes of <1%). Individual gait patterns during real-world running, as characterized by consumer-grade wearable sensors, are not well-represented by the same runner’s in-lab data. Researchers and clinicians should consider “borrowing” information from a pool of many runners to predict individual gait behavior when using biomechanical data to make clinical or sports performance decisions.
... The calculation of the Vertical Average Loading Rate (VALR) is based on the gradient of the initial impact transient, specifically over its linear section, typically spanning from 20% to 80% of the vertical impact peak. In contrast, the Vertical Instantaneous Loading Rate (VILR) is determined by identifying the maximum slope between any two consecutive data points within the same region of interest (Davis et al., 2015). ...
Article
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This study presents a comprehensive review of the correlation between tibial acceleration (TA), ground reaction forces (GRF), and tibial bone loading, emphasizing the critical role of wearable sensor technology in accurately measuring these biomechanical forces in the context of running. This systematic review and meta-analysis searched various electronic databases (PubMed, SPORTDiscus, Scopus, IEEE Xplore, and ScienceDirect) to identify relevant studies. It critically evaluates existing research on GRF and tibial acceleration (TA) as indicators of running-related injuries, revealing mixed findings. Intriguingly, recent empirical data indicate only a marginal link between GRF, TA, and tibial bone stress, thus challenging the conventional understanding in this field. The study also highlights the limitations of current biomechanical models and methodologies, proposing a paradigm shift towards more holistic and integrated approaches. The study underscores wearable sensors’ potential, enhanced by machine learning, in transforming the monitoring, prevention, and rehabilitation of running-related injuries.
... Many studies suggest that reduced shoe support may promote an increase in intrinsic foot muscle strength [62,63]. In the study by Rao and Joseph [64], the subjects are children and have shown that individuals who habitually go barefoot have a significantly lower incidence of pes planus compared to those who wear shoes. ...
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Compared with other sports, running is popular sport for children throughout the world. Over the last few decades, marathon running has become increasingly popular even in the age group below 18 years. While the majority of youth athletes fall within the 16–18 age range, it is noteworthy that there are also participants younger than 12 years engaging in marathon races. Advice on the safety of youth athletes participating in these events is frequently sought by parents, coaches, sport scientists, and medical professionals, particularly concerning potential short- and long-term health consequences. The act of marathon running has the potential to impact key organ systems during the crucial phases of growth and development. To ensure the safety of marathon running in youth runners, it is essential to address multiple physiological and psychological aspects of health. These recommendations are directed towards ensuring the safe participation of youth athletes in marathon races through proper and individualized assessments.
... Vertical ground reaction force (GRF) loading rates (LRs) have been associated with running-related musculoskeletal injuries, including in a prospective study on female runners [1,2]. As such, LR reduction is often a goal of gait retraining, an intervention utilized for the prevention and treatment of running-related injuries [3,4]. ...
... Sportspeople, particularly athletes, who engage in physical activity are more likely to sustain ankle sprains, which account for at least 14% of all emergency hospital visits (Alghadir et al., 2020). The possibility that this figure is higher has also been raised due to the fact that half of those who sustain ankle injuries do not reveal them or seek medical assistance (Davis et al., 2016). During the acute phase, patients additionally experience discomfort, edema, muscle weakness, and impairment in postural control in addition to a loss of range of motion (ROM) (Mattacola & Dwyer, 2002). ...
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Purpose: the purpose of this study was to evaluate the effect of diclofenac sodium gel phonophoresis in grade -l ankle sprain. Materials & Methods: 54 patients were randomly included in this study and allocated equally into two groups. Group-1 was managed with therapeutic ultrasound (digital ultrasound machine, a product of HMS marketed in India with frequency of 1 MHz and 3MHz) with diclofenac sodium gel and group-2 was managed with therapeutic ultrasound with aquasonic gel. Therapeutic ultrasound with diclofenac sodium gel, marketed under the name of Voltaren, was administered at a frequency of 1MHz, an intensity of 0.8 W/cm2 with continuous mode (1:1) for five times a week for 2 weeks. The patients were examined by using Numeric Pain Rating Scale (NPRS) and Foot and Ankle Disability Index (FADI). They were assessed on the baseline, after 1st week, and after 2nd week of treatment. Results: one way ANOVA test was used to determine the significant difference at the 0.05 level of significance. There was reduction in NPRS and FADI p-value 0.000 after 2nd week of treatment in group-1 and group-2. But on the basis of mean difference score of NPRS and FADI, group-1 was better effective in terms of reduction of pain and improvement of function periodical manner (Table 3). Conclusion: significant dose-dependently relief was observed in NPRS and FADI for pain in disability for each group treated with diclofenac sodium gel compared with aquasonic gel using ultrasound. Acoustic streaming increased these benefits significantly when used after topical application of diclofenac sodium gel, and the dose-dependent effects of diclofenac sodium gel using therapeutic ultrasound.
... Specific biomechanical variables such as instantaneous vertical loading rate (IVLR) and vertical impact peak (Milner et al., 2006) have been retrospectively linked with the development of tibial stress fractures, and greater peak patellofemoral joint (PFJ) stress has been observed in runners with patellofemoral pain compared with pain-free individuals (Liao et al., 2018). Additionally, elevated vertical loading rates have been prospectively identified as a risk factor for lower extremity injury in female runners (Davis et al., 2010(Davis et al., , 2016 There is a need for biomechanical risk factor identification, monitoring and feedback. However, there are challenges in measuring biomechanical variables outside laboratory settings. ...
Article
This study investigated the relationships between inertial measurement unit (IMU) acceleration at multiple body locations and 3D motion capture impact landing measures in runners. Thirty healthy runners ran on an instrumented treadmill at five running speeds (9–17 km/h) during 3D motion capture. Axial and resultant acceleration were collected from IMUs at the distal and proximal tibia, distal femur and sacrum. Relationships between peak acceleration from each IMU location and patellofemoral joint (PFJ) peak force and loading rate, impact peak and instantaneous vertical loading rate (IVLR) were investigated using linear mixed models. Acceleration was positively related to IVLR at all lower limb locations (p < 0.01). Models predicted a 1.9–3.2 g peak acceleration change at the tibia and distal femur, corresponding with a 10% IVLR change. Impact peak was positively related to acceleration at the distal femur only (p < 0.01). PFJ peak force was positively related to acceleration at the distal (p = 0.03) and proximal tibia (p = 0.03). PFJ loading rate was positively related to the tibia and femur acceleration in males only (p < 0.01). These findings suggest multiple IMU lower limb locations are viable for measuring peak acceleration during running as a meaningful indicator of IVLR.
... Running biomechanical studies have added value in determining key kinetic and kinematic variables for a running-related injury (RRI) including PFP. Ground reaction force (GRF) variables associated with the impact phase of running, such as vertical loading rates have been associated with RRIs in general [14,15] and specific to PFP [15]. However, other studies have found the opposite [16][17][18], suggesting the value of further study of these variables. ...
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Background Patellofemoral pain (PFP) is among the most common injuries in runners. While multiple risk factors for patellofemoral pain have been investigated, the interactions of variables contributing to this condition have not been explored. This study aimed to classify runners with patellofemoral pain using a combination of factors including biomechanical, anthropometric, and demographic factors through a Classification and Regression Tree analysis. Results Thirty-eight runners with PFP and 38 healthy controls (CON) were selected with mean (standard deviation) age 33 (16) years old and body mass index 22.3 (2.6) kg/m². Each ran at self-selected speed, but no between-group difference was identified (PFP = 2.54 (0.2) m/s x CON = 2.55 (0.1) m/s, P = .660). Runners with patellofemoral pain had different patterns of interactions involving braking ground reaction force impulse, contact time, vertical average loading rate, and age. The classification and regression tree model classified 84.2% of runners with patellofemoral pain, and 78.9% of healthy controls. The prevalence ratios ranged from 0.06 (95% confidence interval: 0.02–0.23) to 9.86 (95% confidence interval: 1.16–83.34). The strongest model identified runners with patellofemoral pain as having higher braking ground reaction force impulse, lower contact times, higher vertical average loading rate, and older age. The receiver operating characteristic curve demonstrated high accuracy at 0.83 (95% confidence interval: 0.74–0.93; standard error: 0.04; P < .001). Conclusions The classification and regression tree model identified an influence of multiple factors associated with patellofemoral pain in runners. Future studies may clarify whether addressing modifiable biomechanical factors may address this form of injury.
... 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. ...
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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.
... Raw marker coordinates were filtered using a fourth-order, zero-lag, low pass Butterworth filter with a cut-off frequency of 10 Hz (Kristianslund et al., 2012). The GRFs were filtered using a third-order, zero-lag, Butterworth low pass filter with a cut-off frequency of 45 Hz (Davis et al., 2016). Knee and ankle joint moments were calculated by the standard inverse dynamics approach and normalised by the body mass. ...
... Over the last 30 years, numerous studies have examined the relationship between common running injuries and specific biomechanics, such as excessive foot pronation and excessive vertical ground reaction force loading rates. [13][14][15][16][17][18][19][20][21] It has been suggested that: excessive peak hip adduction angle may result in abnormal loading in the tibia, [22][23][24] excessive knee internal rotation may increase the torsional strain in the iliotibial band, [25][26][27] and altered kinematics of the rearfoot may change the load distribution within the lower extremity, predisposing individuals to develop a running injury. 24,28 However, it is challenging to find consistent evidence to support which biomechanical variables are related to specific running-related injuries. ...
Article
Background: No systematic review has investigated the main biomechanical variables as predictors of running-related injuries. Objective: To investigate the main biomechanical variables associated with running-related injuries. Methods: Medline via PubMed, EMBASE, SPORTDiscus, Web of Science, and CINAHL were searched from inception until 1 November 2021. Each study included must have investigated the association of at least one biomechanical variable (kinetics, kinematics, electromyography, or pressure distribution) with running injuries. The meta-analysis was conducted, and a modified version of the Downs and Black Quality Index was used for methodological quality evaluation. Results: Across the 82 studies included, 5465 runners were investigated. The meta-analysis was conducted with 11 biomechanical variables from 51 articles (n=2395). The peak hip adduction angle was the sole biomechanical variable associated with running injury and was found to be higher in injured runners (0.57, 95% CI 0.21, 0.94) compared to uninjured runners. However, this result was highly influenced by two studies (out of five studies) conducted by the same group of authors. Conclusion: Clinicians, coaches, and runners should be aware that minimal evidence supports that alterations of running biomechanics are associated with running-related injuries. Heterogeneity in evaluation conditions and inconsistency in the naming and definitions of biomechanical variables make definitive conclusions challenging. Systematic review registration number: PROSPERO, CRD42017068839.
... The most common method of indirectly quantifying loading during running has been by assessing ground reaction forces (GRFs) via force plates. However, there are mixed findings on their association with injury [2,6] A limitation of GRF assessment is that it captures whole-body loading and therefore, does not assess segment-specific loading. Segmental measurement would be more appropriate because injuries are site-specific and because loading distribution throughout the body and across runners are not homogenous. ...
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Background Given the high incidence and heavy burden of running related injuries, large-scale, prospective multifactorial investigations examining potential risk factors are warranted. This study aimed to identify factors associated with running related injuries and to evaluate their potential in injury screening. Study design Prospective cohort study. Materials and methods Two hundred and seventy-four recreational runners were recruited. Clinical measures (strength, range of motion, foot position), injury and training history (via questionnaire), impact loading (via accelerometery) and running technique measures were collected at baseline. Runners were tracked for injury for one year via fortnightly check-ins. A binary logistic regression, (injury versus no injury), was performed for each variable univariably, and then adjusting for age, sex and mileage. A multivariable regression was also performed to evaluate the model’s discriminative ability. Results Of the 225 runners included in the final analysis 52% experienced a running related injury. Injury history in the past year, less navicular drop, and measures of running technique (knee, hip, and pelvis kinematics) were associated with increased odds of injury (p < .05). The multivariable logistic regression model was statistically significant, χ²(11) = 56.45, p < .001, correctly classifying 74% of cases with a sensitivity and specificity of 72% and 76%, respectively. The area under the receiver operating characteristic curve was 0.79 (CI95% = 0.73–0.85), demonstrating acceptable discriminative ability. Conclusions This study found a number of clinical and running technique factors to be associated with prospective running related injuries among recreational runners. With the exception of injury history, the factors identified as being significantly associated with injury may be modifiable and therefore, could form the basis of interventions. Range of motion, spatiotemporal parameters and strength measures were not associated with injury and thus their utilisation in injury prevention practices should be reconsidered.
... Research involving humans, however, has been less conclusive. High average vertical loading rates (74-108 BW/s) and VILRs (88-100 BW/s) have been commonly reported in cross-sectional studies of adults with a history of running-related injury, but prospective studies have generally reported mixed findings (Bredeweg et al., 2013;Davis et al., 2016;Johnson & Davis, 2021;Malisoux et al., , 2022Pohl et al., 2008Pohl et al., , 2009Popp et al., 2023;Ribeiro et al., 2015;Schmida et al., 2022;Tenforde et al., 2019). It is noteworthy that in the current study peak loading rates in adolescents running barefoot and in partial minimal shoes (≈75 BW/s) typically exceeded the VILR diagnostic cut-off values reported for specific running-related injuries (≈55-60 BW/s), including patellofemoral and plantar heel pain in adult populations (Johnson et al., 2020). ...
Article
Footwear may moderate the transiently heightened asymmetry in lower limb loading associated with peak growth in adolescence during running. This repeated-measures study compared the magnitude and symmetry of peak vertical ground reaction force and instantaneous loading rates (VILRs) in adolescents during barefoot and shod running. Ten adolescents (age, 10.6 ± 1.7 years) ran at self-selected speed (1.7 ± 0.3 m/s) on an instrumented treadmill under three counter-balanced conditions; barefoot and shod with partial-minimal and conventional running shoes. All participants were within one year of their estimated peak height velocity based on sex-specific regression equations. Foot-strike patterns, peak vertical ground reaction force and VILRs were recorded during 20 seconds of steady-state running. Symmetry of ground reaction forces was assessed using the symmetry index. Repeated-measures ANOVAs were used to compare conditions (α=.05). Adolescents used a rearfoot foot-strike pattern during barefoot and shod running. Use of conventional shoes resulted in a lower VILR (P < .05, dz = 0.9), but higher VILR asymmetry (P < .05) than running barefoot (dz = 1.5) or in partial-minimal shoes (dz = 1.6). Conventional running shoes result in a lower VILR than running unshod or in partial-minimal shoes but may have the unintended consequence of increasing VILR asymmetry. The findings may have implications for performance, musculoskeletal development and injury in adolescents.
... La rodilla es una de las articulaciones más propensas a sufrir una lesión y las lesiones más típicas en los corredores son el dolor anterior de rodilla, el síndrome de fricción de la banda iliotibial (ITBS), el síndrome de estrés tibial, la fascitis plantar, la tendinitis aquilea y los problemas meniscales (8). Aunque el riesgo de lesiones es un problema multifactorial, la técnica de carrera podría ser un factor clave para entender cómo prevenirlas (9). Esto demuestra la importancia de evaluar adecuadamente la técnica individual de carrera. ...
... Running is a well-liked sport worldwide but as a result, there is also a substantial number of running-related injuries, amounting to 2.5 to 38 injuries per 1000 running hours [1]. Higher mean vertical loading rates have been associated with running related injury risks among runners [2]. To counter these injury risks, better cushioned footwear could help reduce loading rates by reducing maximum vertical ground reaction force (VGRF), increasing time to the first peak of the VGRF and by allowing more deformation in the cushioned material instead [3]. ...
... Dynamic PT variables were taken at initial contact and toe off. Initial contact was chosen since increased load placed on the joints at initial contact is related to running-related musculoskeletal injuries 50,51 ; additionally, hamstring injuries associated with greater anterior PT typically occur right before initial contact in terminal swing. [30][31][32][33] We chose toe off as our second time point because we know that increased anterior PT may be seen as a compensation for decreased terminal hip extension. ...
Article
Standing pelvic tilt (PT) is related to biomechanics linked with increased risk of injury such as dynamic knee valgus. However, there is limited evidence on how standing PT relates to dynamic PT and whether the palpation meter (PALM), a tool to measure standing PT, is valid against 3-dimensional (3D) motion analysis. The purposes of this study were to (1) determine the criterion validity of the PALM for measuring standing PT and (2) identify the relationship between standing PT and dynamic PT during running. Participants (n = 25; 10 males and 15 females) had their standing PT measured by the PALM and 3D motion analysis. Dynamic PT variables were defined at initial contact and toe off. No relationship between the 2 tools was found. Significant large positive relationships between standing PT and PT at initial contact ( r = .751, N = 25, P < .001) and PT at toe off ( r = .761, N = 25, P < .001) were found. Since no relationship was found between standing PT measured by the PALM and 3D motion analysis, the PALM is not a valid alternative to 3D motion analysis. Clinicians may be able to measure standing PT and gain valuable information on dynamic PT, allowing clinicians to quickly assess whether further biomechanical testing is needed.
... Many efforts utilized to address these injuries have focused on investigating various biomechanical factors, such examples include: ground reaction forces, joint kinematics, and spatiotemporal variables. 4,16,18,21,31 Unfortunately, the evidence linking running gait kinematics and kinetics with RRI remains limited and may be influenced by the sample studied. 2,34 Running is a dynamic task that foundationally consists of a series of alternating single leg tasks, requiring adequate neuromuscular control to ensure joint stability and coordination. ...
Article
Background: Biomechanical factors have been associated with running-related injury, but associations are unclear. Dynamic postural stability may be a factor related to injury that has not been studied extensively. Research question: Does dynamic postural control differ in those with a history of running-related injury or those who go on to sustain a running-related injury? Methods: Sixty-five (45 injured; 20 uninjured) and fifty-eight (13 injured; 45 uninjured) collegiate cross-country runners were available for our retrospective and prospective analyses. Time to stabilization and dynamic postural stability index were collected during two separate jump landing tasks (forward and lateral direction) for each leg. Retrospective injury was tabulated by a running history survey. Prospective injuries were recorded by a licensed athletic trainer during the competitive season. Differences in postural stability were compared between injured and uninjured groups and between limbs using two-way ANOVA's. An overall group by leg comparison was completed for each task. Results: The non-dominant limb demonstrated better postural stability indices regardless of injury history. An interaction was observed between limbs and history of injury for the anterior-posterior time to stabilization for the lateral task. The non-dominant limb demonstrated better medio-lateral postural stability indices and time to stabilization during the lateral task, regardless of prospective injury. Significance: Dynamic postural stability was reduced in the dominant limb, but no clear differences were seen between injured and uninjured runners. This suggests dynamic postural stability may be altered in individuals with a history of a running-related injury, but no relationship to subsequent injury was substantiated. Further work is needed to understand how dynamic postural stability may be related to running-related injury.
... (21) Although causal relationships have not been established, research has identified various biomechanical variables which may be associated with injury in competitive and recreational runners. These variables include a greater rate of loading of the vertical ground reaction force (3,9,10,16,19,34,35) and changes in joint motion of the lower extremity. (4-7, 17, 18, 23, 24, 33) However, the relationship between these variables and compensation (i.e., changes in gait) due to injury has not been investigated adequately using prospective and longitudinal research designs. ...
Article
While research on running injuries is common, there is a lack of definitive causal relationships between running injuries and gait mechanics. Additionally, there is a paucity of longitudinal research to understand the development of running injuries. The purpose of this study was to assess the incidence of running injuries and investigate movement characteristics as they relate to injury development in Division-I cross-country athletes over a two-year period. Athletes were evaluated at pre- and post-season with three-dimensional kinematic and kinetic gait analyses. A total of 17 female athletes were evaluated, though sample size varied at each time point. Self-reported injury occurrence data was collected via questionnaires and injury reports were obtained from athletic training staff. Sixteen of the athletes reported at least one injury during the study. The percentage of participants self-reporting injury was greater than the percentage of participants who were evaluated and diagnosed by medical staff each year (year one: 67% vs. 33%; year two: 70% vs. 50%). The most common self-reported and medically confirmed injury location was the left foot, with 7 total reports out of 17 participants. Inferential statistics were not feasible due to an inherently limited sample size, thus effect size (Cohen's d s ) was used to assess differences in mechanics between athletes with and without left foot injury. Several variables, including peak ankle plantarflexion, dorsiflexion, and inversion, peak knee abduction, and hip abduction and adduction were associated with moderate-to-large effect sizes (d s > 0.50). This study demonstrates that injury rates in the literature may be influenced by reporting method. Additionally, this study provides promising information regarding movement characteristics in injured runners and demonstrates the necessity of longitudinal studies of homogenous groups.
Article
OBJECTIVE: to compare step rate and tibial acceleration during an 8-km run performed outdoors versus on a treadmill. DESIGN: Repeated measures observational study. METHODS: Healthy adult runners (females: 9, males: 19) ran 8 km at a self-selected speed outdoors and on a treadmill. A chest mounted inertial measurement unit (IMU) was used to measure step rate while a tibial mounted IMU collected tibial acceleration. Linear mixed-effects models adjusted for speed were used to assess step rate, as well as peak vertical (PV) and peak resultant (PRES) tibial accelerations between conditions and across the 8 km, as well as their interaction. RESULTS: There was a significant interaction between distance and location (est [95% CI] = 0.71 [0.38 to 1.05], p < 0.001) for step rate, with an increase in step rate observed over distance outdoors. There was also a significant interaction between distance and location for PV (-0.13 [-0.25 to -0.00], p = 0.047) and PRES (-0.16 [-0.31 to -0.00], p = 0.047), with both increasing over distance during treadmill running. Overall, PV (3.34 [2.85 to 3.83], p < 0.001) and PRES (5.05 [4.45 to 5.65], p < 0.001) were significantly greater when running outdoors compared to treadmill running. CONCLUSION: Treadmill and overground assessment of step rate were relatively comparable. Tibial acceleration may not be interchangeable with gait analysis in the field.
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Running cadence is crucial in running biomechanics and physiology, impacting performance and injury risk. The relationship between running cadence, height, weight, and gender is explored using data from 29 participants (14 males, 15 females) with varying attributes. Taller individuals tend to have a lower cadence due to longer stride length, while fewer steps are required by heavier individuals at the same pace. A higher cadence is observed in males, possibly due to differences in leg length and muscle fiber composition, although considerable variability exists among individuals of both genders. Linear regression analysis revealed robust models for both genders, with negative correlations between cadence and height, indicating that increased cadence correlates with decreased height for males and females. Females typically have higher BMI than males, with BMI variability in the population. Weight influences running cadence by affecting ground force. Heavier individuals may take fewer steps, but risk increased strain on joints and muscles, raising injury risk. Furthermore, the connection between running cadence and injury risk is investigated. It is found that adjusting cadence significantly reduces stress on weight-bearing joints and prevents common overuse running injuries. It is demonstrated by several reputable studies in the field that even minor cadence increases greatly reduce stress on knee and hip joints during running, making it a commendable method for injury prevention. In conclusion, while height and weight impact running cadence, each person's cadence is unique and influenced by various factors beyond gender alone. Understanding the relationship between running cadence and its impact on injury prevention is crucial for runners seeking to improve performance and avoid injuries.
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Objective To compare clinical measures between patients with chronic exertional compartment syndrome (CECS) and healthy controls and evaluate running biomechanics, physical measurements, and exertional intracompartmental (ICP) changes in adolescent athletes with lower leg CECS. Design Cross-sectional case–control study. Setting Large tertiary care hospital and affiliated injury prevention center. Participants Forty-nine adolescents with CECS (39 F, 10 M; age: 16.9 ± 0.8 years; body mass index (BMI): 23.1 ± 2.9 kg/m ² ; symptom duration: 8 ± 12 months) were compared with 49 healthy controls (39 F, 10 M; age: 6.9 ± 0.8 years; BMI: 20.4 ± 3.7 kg/m ² ). Interventions All participants underwent gait analyses on a force plate treadmill and clinical lower extremity strength and range of motion testing. Patients with chronic exertional compartment syndrome underwent Stryker monitor ICP testing. Main Outcome Measures Symptoms, menstrual history, and ICP pressures of the patients with CECS using descriptive statistics. Mann–Whitney U and χ ² analyses were used to compare CECS with healthy patients for demographics, clinical measures, and gait biomechanics continuous and categorical outcomes, respectively. For patients with CECS, multiple linear regressions analyses were used to assess associations between gait biomechanics, lower extremity strength and range of motion, and with ICP measures. Results The CECS group demonstrated higher mass-normalized peak ground reaction force measures (xBW) compared with controls (0.21 ± 0.05 xBW ( P < 0.001) and were more likely to have impact peak at initial contact ( P = 0.04). Menstrual dysfunction was independently associated with higher postexertion ICP (ß = 14.6; P = 0.02). Conclusions The CECS group demonstrated increased total force magnitude and vertical impact transient peaks. In women with CECS, menstrual dysfunction was independently associated with increased postexertion ICP. These biomechanical and physiological attributes may play a role in the development of CECS.
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Background: To prevent running related injuries and return to sport activities, monitoring the running dynamic parameters (cadence, stride length, ground contact time and vertical oscillation) especially outdoor running is crucial. Previous studies investigated the reliability of these parameters in laboratory settings. However, the nature of outdoor runs is different (curve, uphill, other runners, etc.) and challenging in terms of equipment (simple) and environments (grass, asphalt, rubber, etc.). Therefore, the reliability of these parameters using a fitness watch synced with accelerometer needed to be investigated. Objective: To investigate the reliability of running parameters measured using fitness watches and accelerometers during outdoor runs. Materials and methods: 30 healthy volunteers (age 25.8±9.6 years, height 167.2±9.3 cm, weight 62.4±14.2 kg, and body mass index 22.2±3.8 kg/m2) participated in the study. They wore a fitness watch and attached a synced accelerometer at their pants. They completed 2 running laps (800 meters each) at their comfortable speeds. Resting periods were provided between laps. To control the speed for the second lap, the watch was set the maximum and minimum speed and set vibration and sound alarm mode. Running parameters include cadence, stride length, vertical oscillation, and ground contact time. Results: The reliability of the four running parameters (cadence, stride length, ground contact time, and vertical oscillation), indicated by the intraclass correlation coefficients (ICC (3,k)) was 0.94, 0.97, 0.98 and 0.99, respectively. Very high reliability values were confirmed. Conclusion: Using a fitness watch synced with an accelerometer during outdoor runs, running dynamic parameters (cadence, stride length, ground contact time, and vertical oscillation) illustrated very high levels of reliability.
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Increased midsole deformation can limit exposure to high impact and vibration magnitudes while running. The aim of this study was to evaluate the effect of shoes eliciting different midsole deformation on ground reaction forces, heel impact, soft tissue vibrations and bone vibrations. Forty-eight runners performed a 5-minutes running task on an instrumented treadmill at a self-selected pace with four different shoes. Midsole horizontal and vertical deformations were quantified with relative displacement of seven reflective markers placed on the midsole of the shoe and tracked by eight optoelectronic cameras. Heel impacts, soft tissue and bone vibrations of lower leg muscle groups, sacrum and head were quantified with tri-axial accelerometers. Continuous wavelet transform was used to assess magnitude and frequency of the acceleration data. Linear mixed models and non-parametric one-dimensional regressions between the accelerometer data and shoe deformation were performed. Greater horizontal and vertical deformations decreased the magnitude (up to 4.6% per mm) and frequency (up to 0.6 Hz per mm) of soft tissue vibrations and bone accelerations. Accelerations of the heel, tibia, gastrocnemius medialis and vastus lateralis were more influenced than the sacrum and head. Increasing midsole deformation could therefore mitigate the risk of injury, while increasing running comfort and smoothness.
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With the increase of female sports participants, the attention to female sports protection is getting higher and higher. However, most past sports science and sports medicine research has emphasized men, so the possible different effects of gender factors are less discussed. To explore whether women are more prone to sports injuries, we should start with the differences between men and women, which include biological sex (sex) and social sex (gender). This article reviewed epidemiological data on the incidence of sports injuries in male and female athletes and found that overall, there was no difference in the incidence of sports injuries between male and female athletes. However, when looking at specific sports, such as swimming, and water polo, there were sex differences in the incidence of sports injuries. For common sports injuries, such as anterior cruciate ligament injuries, stress fractures, and concussions, female athletes had a higher incidence of injury. The current challenges in sports injury prevention work or related research include the lack of research in women's sports science and sports medicine and the disregard of social gender factors. Finally, a classification of sports injury risk factors based on the risk modification and sports injury prevention models incorporating sex and gender considerations are recommended for future practice.
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Some of the earliest biomechanics research focused on running and the ground reaction forces generated with each step. Research in running gait accelerated in the 1970's as the growing popularity in running increased attention to the musculoskeletal injuries sustained by runners. Despite decades of high-quality research, running remains the most common cause of exercise-related musculoskeletal injuries and rates of overuse running-related injuries (RRI) have not appreciably declined since the research began. One leading area of running gait research focuses on discrete variables derived from the vertical ground reaction force, such as the vertical loading rate. Across sub-disciplines of running gait research, vertical loading rate is often discussed as the primary and undisputed variable associated with RRI despite only low to moderate evidence that retrospectively or prospectively injured runners generate greater vertical loading rates than uninjured counterparts. The central thesis of this review is that relying on vertical loading rate is insufficient to establish causal mechanisms for RRI etiology. To present this argument, this review examines the history of the 'impacts cause injury' hypothesis, including a historical look at ground reaction forces in human running and the research from which this hypothesis was generated. Additionally, a synthesis of studies that have tested the hypothesis is provided and recommendations for future research are discussed. Although it is premature to reject or support the 'impacts cause injury' hypothesis, new knowledge of biomechanical risk factors for RRI will remain concealed until research departs from the current path or adopts new approaches to previous paradigms.
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Asymptomatic bone marrow edema (aBME) is a non-specific radiographic finding often found in athletes. Although aBME may represent the body's physiological response to training load, the etiology, MRI characteristics, and natural history of aBME remain unknown. To better characterize aBME in the lower extremities of military trainees and athletes. A systematic literature review in accordance with PRISMA guidelines was performed to identify primary research articles reporting on aBME in the lower extremities of athletes and military trainees. We identified 347 unique articles and after applying inclusion and exclusion criteria, 10 articles were included for qualitative synthesis. There were a total of 444 patients with an average age of 28.4±9.6 included. The most commonly used MRI sequences were proton-density with fat-saturation and T1-weighted imaging. The pattern of BME was inconsistently described, with various classification schemas used. The changes in aBME during longitudinal follow-up were dynamic and demonstrated both radiographic progression and regression. aBME is a highly prevalent and radiographically dynamic entity observed in high-level athletes and military trainees. Although follow-up was limited in the included studies, aBME may represent a natural, non-pathologic, reaction in response to specific biomechanical stressors.
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Background: Providing clinicians with an accurate method to predict kinetic measurements using 2D kinematic motion analysis is crucial to the management of distance runners. Evidence is needed to compare the accuracy of 2D and 3D kinematic measurements as well as measured and estimated kinetic variables. Purposes: The objectives of this study were to (1) compare 2D video analysis of running kinematics with gold standard 3D motion capture and, (2) to evaluate published equations which estimate running kinetics using 2D kinematic and spatiotemporal values and modify these equations based on study findings. Design: Controlled laboratory study, cross-sectional design. Methods: Runners who averaged at least 20 miles per week were invited to participate. Athletes ran on an instrumented treadmill at their preferred training pace for a 6-minute warm-up. Markers were placed over designated anatomical landmarks on both sides of the pelvis as well as the left lower extremity. Subjects then ran at their preferred speed and kinematic data were recorded using both the 2D and 3D camera systems at 240 frames/second. Additionally, ground reaction forces were recorded at 1200Hz. 2D and 3D kinematic values were compared and published kinetic prediction formulas were tested. Linear regression was used to develop new prediction equations for average loading rate (AVG_LR), peak vertical ground reaction force (VERT_GRF), and peak braking force (PK_BRK). Paired t-tests were used to assess differences between the 2D and 3D kinematic variables and the measured (MEAS) and calculated (CALC) kinetic variables. Results: Thirty runners (13 men and 17 women) voluntarily consented to participate in this study and the mean age of the participants was 31.8 years (range 20 to 48 years). Although significant differences existed, all 2D kinematic measures were within 2°-5° of 3D kinematic measures. Published prediction equations for AVG_LR and VERT_GRF were supported, but new prediction equations showed higher R2 for AVG_LR (0.52) and VERT_GRF (0.75) compared to previous work. A new prediction equation for PK_BRK was developed. No significant differences were found between the MEAS and CALC kinetic variables using the new equations. Conclusion: Accurate predictions of kinetic variables can be made using spatiotemporal and 2D kinematic variables. Level of evidence: Level 2.
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Despite several studies that have been conducted on running injuries, the risk factors for running-related injuries are still not clear in the literature. The aim of this study was to systematically review prospective cohort studies that investigated the risk factors for running injuries in general. We conducted electronic searches without restriction of language on EMBASE (1980 to Dec 2012), PUBMED (1946 to Dec 2012), CINAHL (1988 to Dec 2012) SPORTDiscus (1977 to Dec 2012), Latin American and Caribbean Centre on Health Sciences Information (1985 to Dec 2012) and Scientific Electronic Library Online (1998 to Dec 2012) databases, using subject headings, synonyms, relevant terms and variant spellings for each database. Only prospective cohort studies investigating the risk factors for running-related musculoskeletal injuries were included in this review. Two independent reviewers screened each article and, if they did not reach a consensus, a third reviewer decided whether or not the article should be included. Year of publication, type of runners, sample size, definition of running-related musculoskeletal injury, baseline characteristics, reported risk factors and the statistical measurement of risk or protection association were extracted from the articles. A scale adapted by the authors evaluated the risk of bias of the articles. A total of 11 articles were considered eligible in this systematic review. A total of 4,671 pooled participants were analysed and 60 different predictive factors were investigated. The main risk factor reported was previous injury (last 12 months), reported in 5 of the 8 studies that investigated previous injuries as a risk factor. Only one article met the criteria for random selection of the sample and only six articles included a follow-up of 6 months or more. There was no association between gender and running injuries in most of the studies. It is possible that eligible articles for this review were published in journals that were not indexed in any of the searched databases. We found a great heterogeneity of statistical methods between studies, which prevented us from performing a meta-analysis. The main risk factor identified in this review was previous injury in the last 12 months, although many risk factors had been investigated in the literature. Relatively few prospective studies were identified in this review, reducing the overall ability to detect risk factors. This highlights the need for more, well designed prospective studies in order to fully appreciate the risk factors associated with running.
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Background Previous studies of foot strike patterns of distance runners in road races have typically found that the overwhelming majority of shod runners initially contact the ground on the rearfoot. However, none of these studies has attempted to quantify foot strike patterns of barefoot or minimally shod runners. This study classifies foot strike patterns of barefoot and minimally shod runners in a recreational road race. Methods High-speed video footage was obtained of 169 barefoot and 42 minimally shod distance runners at the 2011 New York City Barefoot Run. Foot strike patterns were classified for each runner, and frequencies of forefoot, midfoot, and rearfoot striking were compared between the barefoot and minimally shod groups. Results A total of 59.2% of barefoot runners were forefoot strikers, 20.1% were midfoot strikers, and 20.7% were rearfoot strikers. For minimally shod runners, 33.3% were forefoot strikers, 19.1% were midfoot strikers, and 47.6% were rearfoot strikers. Foot strike distributions for barefoot and minimally shod runners were significantly different both from one another and from previously reported foot strike distributions of shod road racers. Conclusion Foot strike patterns differ between barefoot and minimally shod runners, with forefoot striking being more common, and rearfoot striking less common in the barefoot group.
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Anterior compartment pressures of the leg as well as kinematic and kinetic measures are significantly influenced by running technique. It is unknown whether adopting a forefoot strike technique will decrease the pain and disability associated with chronic exertional compartment syndrome (CECS) in hindfoot strike runners. For people who have CECS, adopting a forefoot strike running technique will lead to decreased pain and disability associated with this condition. Case series; Level of evidence, 4. Ten patients with CECS indicated for surgical release were prospectively enrolled. Resting and postrunning compartment pressures, kinematic and kinetic measurements, and self-report questionnaires were taken for all patients at baseline and after 6 weeks of a forefoot strike running intervention. Run distance and reported pain levels were recorded. A 15-point global rating of change (GROC) scale was used to measure perceived change after the intervention. After 6 weeks of forefoot run training, mean postrun anterior compartment pressures significantly decreased from 78.4 ± 32.0 mm Hg to 38.4 ± 11.5 mm Hg. Vertical ground-reaction force and impulse values were significantly reduced. Running distance significantly increased from 1.4 ± 0.6 km before intervention to 4.8 ± 0.5 km 6 weeks after intervention, while reported pain while running significantly decreased. The Single Assessment Numeric Evaluation (SANE) significantly increased from 49.9 ± 21.4 to 90.4 ± 10.3, and the Lower Leg Outcome Survey (LLOS) significantly increased from 67.3 ± 13.7 to 91.5 ± 8.5. The GROC scores at 6 weeks after intervention were between 5 and 7 for all patients. One year after the intervention, the SANE and LLOS scores were greater than reported during the 6-week follow-up. Two-mile run times were also significantly faster than preintervention values. No patient required surgery. In 10 consecutive patients with CECS, a 6-week forefoot strike running intervention led to decreased postrunning lower leg intracompartmental pressures. Pain and disability typically associated with CECS were greatly reduced for up to 1 year after intervention. Surgical intervention was avoided for all patients.
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Case series. Patellofemoral pain is a common overuse injury in runners. Recent findings suggest that patellofemoral pain is related to high-impact loading associated with a rearfoot strike pattern. This case series describes the potential training effects of a landing pattern modification program to manage patellofemoral pain in runners. Three female runners with unilateral patellofemoral pain who initially presented with a rearfoot strike pattern underwent 8 sessions of landing pattern modification program using real-time audio feedback from a force sensor placed within the shoe. Ground reaction forces during running were assessed with an instrumented treadmill. Patellofemoral pain symptoms were assessed using 2 validated questionnaires. Finally, running performance was measured by self-reported best time to complete a 10-km run in the previous month. The runners were assessed before, immediately after, and 3 months following training. The landing pattern of runners was successfully changed from a rearfoot to a nonrearfoot strike pattern after training. This new pattern was maintained 3 months after the program. The vertical impact peak and rates of loading were shown to be reduced. Likewise, the symptoms related to patellofemoral pain and associated functional limitations were improved. However, only 1 of the participants reported improved running performance after the training. This case series provided preliminary data to support further investigation of interventions leading to landing pattern modification in runners with patellofemoral pain. Therapy, level 4.
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Cross-sectional experimental laboratory study. To examine differences in running mechanics between runners who had previously sustained iliotibial band syndrome (ITBS) and runners with no knee-related running injuries. ITBS is the second leading cause of knee pain in runners and the most common cause of lateral knee pain. Despite its prevalence, few biomechanical studies have been conducted to better understand its aetiology. Because the iliotibial band has both femoral and tibial attachments, it is possible that atypical hip and foot mechanics could result in the development of ITBS. The running mechanics of 35 females who had previously sustained ITBS were compared to 35 healthy age-matched and running distance-matched healthy females. Comparisons of hip, knee, and ankle 3-dimensional kinematics and internal moments during the stance phase of running gait were measured. The ITBS group exhibited significantly greater peak rearfoot invertor moment, peak knee internal rotation angle, and peak hip adduction angle compared to controls. No significant differences in peak rearfoot eversion angle, peak knee flexion angle, peak knee external rotator moment, or peak hip abductor moments were observed between groups. Females with a previous history of ITBS demonstrate a kinematic profile that is suggestive of increased stress on the iliotibial band. These results were generally similar to those reported for a prospective study conducted within the same laboratory environment.
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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.
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We investigated the relationship between functional and static foot posture and medial tibial stress syndrome in distance runners. Twenty-eight runners with a clinical diagnosis of medial tibial stress syndrome and 12 asymptomatic runners were assessed with the Foot Posture Index to measure static overpronation. Range of motion was measured at the talocrural joint, with the knee extended and flexed as was range of motion at the first metatarsophalangeal joint and the angular difference between the neutral and relaxed calcaneal stance positions. Each participant was then videotaped while running on a treadmill shod and unshod. This videotape was analyzed using freeze frame to identify abnormal or mistimed pronation at each phase of gait. The results were analyzed using logistic regression to give the probability that a runner is likely to experience medial tibial stress syndrome, predicted from the static measurements and dynamic observations. Variables identified as being significant predictors of medial tibial stress syndrome were the difference between the neutral and relaxed calcaneal stance positions, range of motion of the talocrural joint with the knee extended, early heel lift and abductory twist during gait, and apropulsive gait. Runners with suspected symptoms of medial tibial stress syndrome should be assessed dynamically and statically for abnormal or mistimed pronation.
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To provide an extensive and up to date database for specific running related injuries, across the sexes, as seen at a primary care sports medicine facility, and to assess the relative risk for individual injuries based on investigation of selected risk factors. Patient data were recorded by doctors at the Allan McGavin Sports Medicine Centre over a two year period. They included assessment of anthropometric, training, and biomechanical information. A model was constructed (with odds ratios and their 95% confidence intervals) of possible contributing factors using a dependent variable of runners with a specific injury and comparing them with a control group of runners who experienced a different injury. Variables included in the model were: height, weight, body mass index, age, activity history, weekly activity, history of injury, and calibre of runner. Most of the study group were women (54%). Some injuries occurred with a significantly higher frequency in one sex. Being less than 34 years old was reported as a risk factor across the sexes for patellofemoral pain syndrome, and in men for iliotibial band friction syndrome, patellar tendinopathy, and tibial stress syndrome. Being active for less than 8.5 years was positively associated with injury in both sexes for tibial stress syndrome; and women with a body mass index less than 21 kg/m(2) were at a significantly higher risk for tibial stress fractures and spinal injuries. Patellofemoral pain syndrome was the most common injury, followed by iliotibial band friction syndrome, plantar fasciitis, meniscal injuries of the knee, and tibial stress syndrome. Although various risk factors were shown to be positively associated with a risk for, or protection from, specific injuries, future research should include a non-injured control group and a more precise measure of weekly running distance and running experience to validate these results.
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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.
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We have shown that stress fractures can be induced in the tibial diaphysis of an animal model by the repeated application of non-traumatic impulsive loads. The right hind limbs of 31 rabbits were loaded for three to nine weeks and changes in the bone were monitored by radiography and bone scintigraphy. The presence of stress fractures was confirmed histologically in some cases. Most animals sustained a stress fracture within six weeks and there was a positive correspondence between scintigraphic change and radiological evidence. Microscopic damage was evident at the sites of positive bone scans. The progression, location, and time of onset of stress fractures in this animal model were similar to those in clinical reports, making the model a useful one for the study of the aetiology of stress fractures.
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The aim of our study was to assess the interday test-retest reliability (focussing on the separate contribution of systematic and random error) of selected 10-trial mean ground reaction force (GRF) parameters and GRF symmetry indices measured during running. Ten competitive male heel-strike runners (aged, 26.2 ± 5.7 years) performed 10 successful running trials across the force platform at a constant velocity of 4.0 m · s -1 ± 10% wearing their customary running footwear. The testing procedure was repeated under similar conditions 1 week later. The results showed no statistically significant differences between the means of Test 1 and Test 2 for most GRF parameters and symmetry indices, indicating non-significant systematic error. Correlation coefficients ranged from 0.73 to 0.99 for GRF parameters. Random error was small, with SE(meas) less than 10% of the Test 1 mean value for almost all GRF parameters. Symmetry indices displayed correlation coefficients ranging from -0.44 to 0.91. Based on these and the size of the SE(meas), the symmetry indices displayed variable reliability, with the most reliable being those associated with peak vertical active force and peak horizontal propulsive force.
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• This prospective study of 583 habitual runners used baseline information to examine the relationship of several suspected risk factors to the occurrence of running-related injuries of the lower extremities that were severe enough to affect running habits, cause a visit to a health professional, or require use of medication. During the 12-month follow-up period, 252 men (52%) and 48 women (49%) reported at least one such injury. The multiple logistic regression results identified that running 64.0 km (40 miles) or more per week was the most important predictor of injury for men during the follow-up period (odds ratio=2.9). Risk also was associated with having had a previous injury in the past year (odds ratio = 2.7) and with having been a runner for less than 3 years (odds ratio=2.2). These results suggest that the incidence of lower-extremity injuries is high for habitual runners, and that for those new to running or those who have been previously injured, reducing weekly distance is a reasonable preventive behavior.(Arch Intern Med. 1989;149:2565-2568)
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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.
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Atypical running gait biomechanics are considered a primary factor in the aetiology of iliotibial band syndrome (ITBS). However, a general consensus on the underpinning kinematic differences between runners with and without ITBS is yet to be reached. This lack of consensus may be due in part to three issues: gender differences in gait mechanics, the pre-selection of discrete biomechanical variables, and/or relatively small sample sizes. Therefore, this study was designed to address two purposes: (1) examining differences in gait kinematics for male and female runners experiencing ITBS at the time of testing and (2) assessing differences in gait kinematics between healthy gender- and age-matched runners as compared with their ITBS counterparts using waveform analysis. Ninety-six runners participated in this study: 48 ITBS and 48 healthy runners. The results show that female ITBS runners exhibited significantly greater hip external rotation compared to male ITBS and female healthy runners. On the contrary, male ITBS runners exhibited significantly greater ankle internal rotation compared to healthy males. These results suggest that care should be taken to account for gender when investigating the biomechanical aetiology of ITBS.
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There are currently no generally accepted, consistent results that clearly characterize factors causing Achilles tendon pain (AT) in runners. Therefore, we carried out a prospective study to evaluate the multifactorial influence of clinical, biomechanical (isometric strength measurements and three-dimensional kinematics) and trainingrelated risk factors on the development of AT. Two hundred sixty-nine uninjured runners were recruited and underwent an initial examination. One hundred fortytwo subjects completed their participation by submitting training information on a weekly basis over a maximal period of 1 year. Forty-five subjects developed an overuse injury, with 10 runners suffering from AT. In an uninjured state, AT runners already demonstrated decreased knee flexor strength and abnormal lower leg kinematics (sagittal knee and ankle joint) compared with a matched control group. A relationship between years of running experience or previous overuse injuries and the development of new symptoms could not be established. The interrelationship of biomechanical and training-specific variables on the generation of AT is evident. A combination of alterations in lower leg kinematics and higher impacts caused by fast training sessions might lead to excessive stress on the Achilles tendon during weight bearing and thus to AT in recreational runners.
Article
Iliotibial band syndrome (ITBS) is a common knee overuse injury among female runners. Atypical discrete trunk and lower extremity biomechanics during running may be associated with the etiology of ITBS. Examining discrete data points limits the interpretation of a waveform to a single value. Characterizing entire kinematic and kinetic waveforms may provide additional insight into biomechanical factors associated with ITBS. Therefore, the purpose of this cross-sectional investigation was to determine whether female runners with previous ITBS exhibited differences in kinematics and kinetics compared to controls using a principal components analysis (PCA) approach. Forty participants comprised two groups: previous ITBS and controls. Principal component scores were retained for the first three principal components and were analyzed using independent t-tests. The retained principal components accounted for 93-99% of the total variance within each waveform. Runners with previous ITBS exhibited low principal component one scores for frontal plane hip angle. Principal component one accounted for the overall magnitude in hip adduction which indicated that runners with previous ITBS assumed less hip adduction throughout stance. No differences in the remaining retained principal component scores for the waveforms were detected among groups. A smaller hip adduction angle throughout the stance phase of running may be a compensatory strategy to limit iliotibial band strain. This running strategy may have persisted after ITBS symptoms subsided.
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The knee joints of adult rabbits were subjected to daily one hour intervals of impulsive loading equivalent to their body weight at 60 cpm. They developed changes in their knee joints consistent with those of degenerative joint disease. The cartilage destruction was preceded by stiffening of the underlying subchondral bone. Numerous healing trabecular microfractures were associated with this increased stiffening. Similar microfractures have been observed in human specimens. The implications of these findings to bone remodelling and osteoarthritis are discussed.
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"Excessive" pronation is often implicated as a risk factor for anterior knee pain (AKP). The amount deemed excessive is typically calculated using the means and standard deviations reported in the literature. However, when using this method, few studies find an association between pronation and AKP. An alternative method of defining excessive pronation is to use the joints' available range of motion (ROM). The purposes of this study were to (1) evaluate pronation in the context of the joints' ROM and (2) compare this method to traditional pronation variables in healthy and injured runners. Thirty-six runners (19 healthy, 17 AKP) had their passive pronation ROM measured using a custom-built device and a motion capture system. Dynamic pronation angles during running were captured and compared with the available ROM. In addition, traditional pronation variables were evaluated. No significant differences in traditional pronation variables were noted between healthy and injured runners. In contrast, injured runners used significantly more of their available ROM, maintaining a 4.21° eversion buffer, whereas healthy runners maintained a 7.25° buffer (P = .03, ES = 0.77). Defining excessive pronation in the context of the joints' available ROM may be a better method of defining excessive pronation and distinguishing those at risk for injury.
Article
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.
Article
Although the biomechanical properties of the various types of running foot strike (rearfoot, midfoot, and forefoot) have been studied extensively in the laboratory, only a few studies have attempted to quantify the frequency of running foot strike variants among runners in competitive road races. We classified the left and right foot strike patterns of 936 distance runners, most of whom would be considered of recreational or sub-elite ability, at the 10 km point of a half-marathon/marathon road race. We classified 88.9% of runners at the 10 km point as rearfoot strikers, 3.4% as midfoot strikers, 1.8% as forefoot strikers, and 5.9% of runners exhibited discrete foot strike asymmetry. Rearfoot striking was more common among our sample of mostly recreational distance runners than has been previously reported for samples of faster runners. We also compared foot strike patterns of 286 individual marathon runners between the 10 km and 32 km race locations and observed increased frequency of rearfoot striking at 32 km. A large percentage of runners switched from midfoot and forefoot foot strikes at 10 km to rearfoot strikes at 32 km. The frequency of discrete foot strike asymmetry declined from the 10 km to the 32 km location. Among marathon runners, we found no significant relationship between foot strike patterns and race times.
Article
lower-limb stress fracture is one of the most common types of running injuries. There have been several studies focusing on the association between stress fractures and biomechanical factors. In the current study, the ground reaction force and loading rate are examined. There is disagreement in the literature about whether the history of stress fractures is associated with ground reaction forces (either higher or lower than control), or with loading rates. a systematic review of the literature was conducted on the relationship between the history of tibial and/or metatarsal stress fracture and the magnitude of the ground reaction force and loading rate. Fixed-effect meta-analysis techniques were applied to determine whether or not the ground reaction force and/or loading rate are different between the stress fracture and control groups. thirteen articles were identified through a systematic search of the literature. About 54% of these articles reported significantly different vertical ground reaction force and/or loading rate between the stress fracture and control groups. Other studies (~46%) did not observe any significant difference between the two groups. Meta-analysis results showed no significant differences between the ground reaction force of the lower-limb stress fracture and control groups (P>0.05). However, significant differences were observed for the average and instantaneous vertical loading rates (P<0.05). the currently available data does not support the hypothesis that there is a significant difference between the ground reaction force of subjects experiencing lower-limb stress fracture and control groups. Instead, the vertical loading rate was found to be significantly different between the two groups.
Article
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.
Article
Bovine joints were oscillated under the maximum possible static load in a device which measured their coefficients of fraction while the joints were running. Joint wear was evaluated by gross and histologic inspection. Joints oscillating under loads, just below the structural capability of the joints, did not show significant wear even after long periods of time. When periodic impact loading was added to this regimen, cartilage wear became rapid and was easily discernible. The implications of these findings to the wearing away of articular cartilage are discussed.
Article
Ground reaction forces and center of pressure (C of P) patterns were studied in 17 subjects running at 4.5 ms−1. The subjects were classified as rearfoot or midfoot strikers according to the location of the C of P at the time of first contact between foot and ground. The C of P path in the rearfoot group showed a continuous anterior movement during support while the C of P in most of the midfoot group migrated posteriorly during the first 20 ms of the support phase. Variability in both groups was most marked during early support. The mean peak to peak force components were 3 BW, 1 BW and 0.3 BW in the vertical, anteroposterior and mediolateral directions respectively. Consistent differences between groups were noted in all three components, but individual differences within a given group were also considerable. The C of P patterns are presented in conjunction with ground reaction force data, and the implications of the results in the areas of running mechanics, shoe design and sports injury are discussed.
Article
Tibial stress fractures (TSF) are among the most serious running injuries, typically requiring 6-8 wk for recovery. This cross-sectional study was conducted to determine whether differences in structure and running mechanics exist between trained distance runners with a history of prior TSF and those who have never sustained a fracture. Female runners with a rearfoot strike pattern, aged between 18 and 45 yr and running at least 32 km.wk(-1), were recruited for this study. Participants in the study were 20 subjects with a history of TSF and 20 age- and mileage-matched control subjects with no previous lower extremity bony injuries. Kinematic and kinetic data were collected during overground running at 3.7 m.s(-1) using a six-camera motion capture system, force platform, and accelerometer. Variables of interest were vertical impact peak, instantaneous and average vertical loading rates, instantaneous and average loading rates during braking, knee flexion excursion, ankle and knee stiffness, and peak tibial shock. Tibial varum was measured in standing. Tibial area moment of inertia was calculated from tibial x-ray studies for a subset of runners. The TSF group had significantly greater instantaneous and average vertical loading rates and tibial shock than the control group. The magnitude of tibial shock predicted group membership successfully in 70% of cases. These data indicate that a history of TSF in runners is associated with increases in dynamic loading-related variables.
Article
Identification of mechanical factors associated with patellofemoral pain, the most prevalent running injury, is necessary to help in injury prevention, but unfortunately they remain elusive. Runners who develop patellofemoral pain have increased knee joint angular impulse in the frontal plane. Case control study; Level of evidence, 3. A retrospective study compared knee abduction impulses of 20 patellofemoral pain patients with those of 20 asymptomatic patients. A second prospective study quantified knee angular impulses during the stance phase of running of 80 runners at the beginning of the summer running season. Epidemiologic data were then collected, recording the type and severity of injury of these runners during a 6-month running period. The patellofemoral pain patients in the retrospective study had significantly higher (P = .026) knee abduction impulses (17.0 +/- 8.5 Nms) than did the asymptomatic patients (12.5 +/- 5.5 Nms). Six patients developed patellofemoral pain during the prospective study. The prospective data showed that patients who developed patellofemoral pain had significantly higher (P = .042) knee abduction impulses (9.2 +/- 3.7 Nms) than did matched patients who remained uninjured (4.7 +/- 3.5 Nms). The data indicate that increased knee abduction impulses should be deemed risk factors that play a role in the development of patellofemoral pain in runners. Footwear and running style can influence knee angular impulse, and the appropriate manipulation of these variables may play a preventive role for patients who are predisposed to patellofemoral pain.
Article
There are various recommendations by many coaches regarding foot landing techniques in distance running that are meant to improve running performance and prevent injuries. Several studies have investigated the kinematic and kinetic differences between rearfoot strike (RFS), midfoot strike (MFS), and forefoot strike (FFS) patterns at foot landing and their effects on running efficiency on a treadmill and over ground conditions. However, little is known about the actual condition of the foot strike pattern during an actual road race at the elite level of competition. The purpose of the present study was to document actual foot strike patterns during a half marathon in which elite international level runners, including Olympians, compete. Four hundred fifteen runners were filmed by 2 120-Hz video cameras in the height of 0.15 m placed at the 15.0-km point and obtained sagittal foot landing and taking off images for 283 runners. Rearfoot strike was observed in 74.9% of all analyzed runners, MFS in 23.7%, and FFS in 1.4%. The percentage of MFS was higher in the faster runners group, when all runners were ranked and divided into 50 runner groups at the 15.0-km point of the competition. In the top 50, which included up to the 69th place runner in actual order who passed the 15-km point at 45 minutes, 53 second (this speed represents 5.45 m x s(-1), or 15 minutes, 17 seconds per 5 km), RFS, MFS, and FFS were 62.0, 36.0, and 2.0%, respectively. Contact time (CT) clearly increased for the slower runners, or the placement order increased (r = 0.71, p < or = 0.05). The CT for RFS + FFS for every 50 runners group significantly increased with increase of the placement order. The CT for RFS was significantly longer than MFS + FFS (200.0 +/- 21.3 vs. 183.0 +/- 16 millisecond). Apparent inversion (INV) of the foot at the foot strike was observed in 42% of all runners. The percentage of INV for MFS was higher than for RFS and FFS (62.5, 32.0, and 50%, respectively). The CT with INV for MFS + FFS was significantly shorter than the CT with and without INV for RFS. Furthermore, the CT with INV was significantly shorter than push-off time without INV for RFS. The findings of this study indicate that foot strike patterns are related to running speed. The percentage of RFS increases with the decreasing of the running speed; conversely, the percentage of MFS increases as the running speed increases. A shorter contact time and a higher frequency of inversion at the foot contact might contribute to higher running economy.
Article
Iliotibial band syndrome is the leading cause of lateral knee pain in runners. Despite its high prevalence, little is known about the biomechanics that lead to this syndrome. The purpose of this study was to prospectively compare lower extremity kinematics and kinetics between a group of female runners who develop iliotibial band syndrome compared to healthy controls. It was hypothesized that runners who develop iliotibial band syndrome will exhibit greater peak hip adduction, knee internal rotation, rearfoot eversion and no difference in knee flexion at heel strike. Additionally, the iliotibial band syndrome group were expected to have greater hip abduction, knee external rotation, and rearfoot inversion moments. A group of healthy female recreational runners underwent an instrumented gait analysis and were then followed for two years. Eighteen runners developed iliotibial band syndrome. Their initial running mechanics were compared to a group of age and mileage matched controls with no history of knee or hip pain. Comparisons of peak hip, knee, rearfoot angles and moments were made during the stance phase of running. Variables of interest were averaged over the five running trials, and then averaged across groups. The iliotibial band syndrome group exhibited significantly greater hip adduction and knee internal rotation. However, rearfoot eversion and knee flexion were similar between groups. There were no differences in moments between groups. The development of iliotibial band syndrome appears to be related to increased peak hip adduction and knee internal rotation. These combined motions may increase iliotibial band strain causing it to compress against the lateral femoral condyle. These data suggest that treatment interventions should focus on controlling these secondary plane movements through strengthening, stretching and neuromuscular re-education.
Calculation of vertical load rates in the absence of vertical impact peaks. Presented at the American Society of Biomechanics Meeting
  • R Willy
  • M B Pohl
  • I S Davis