Running Pattern Research Articles

Using motion capture technology to assess gait patterns in runners and investigate injury risks: A short review

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.

Intra- and interlimb effects of gait retraining in individuals with knee hyperextension

BackgroundGait retraining, which typically focuses on the most severely affected limb or joint, has shown promising results in treating faulty running and walking patterns. The closed-chain nature of gait during the stance phase may influence kinematic changes in the adjacent joints of the trained leg. In addition, the coupled nature of the lower extremity motion of gait suggests that changes in one leg may transfer to the other. This study aimed to assess the intra- and inter-limb transfer of kinematic changes following gait retraining to reduce knee extension in individuals with hyperextension walking patterns. MethodsSeventeen women with knee hyperextension gait patterns participated in six treadmill retraining sessions. All participants received verbal and real-time visual kinematic feedback in the form of knowledge of results. This intervention study took place at the Gait Analysis Laboratory at the University of Iowa. Mean peak sagittal-plane lower extremity joint kinematics during overground walking at pretraining, post-training, and 1- and 8-month follow-ups were calculated for analysis and comparisons. FindingsThe post-training changes in ankle range of motion returned to baseline values by the 8-month follow-up. There was a significant transfer effect of kinematic changes to the untrained knee following gait retraining. InterpretationTraining one knee did not result in long-term compensatory kinematic changes in the other joints. In addition, the improvements in knee extension range of motion were transferred to the untrained knee and retained at the 8-month follow-up. This study supports the use of gait retraining as an effective clinical intervention.

Lower limb joint loading patterns in runners with and without a heightened risk of knee osteoarthritis: Data from the TRAIL cohort

Lower limb joint loading patterns in runners with and without a heightened risk of knee osteoarthritis: Data from the TRAIL cohort

Using dynamic ultrasound to assess Achilles tendon mechanics during running: The effect on running pattern and muscle–tendon junction tracking

Achilles tendon strain can be quantified using dynamic ultrasound, but its use in running is limited. Minimal effects on running pattern and acceptable test–retest reliability of muscle–tendon junction (MTJ) tracking are prerequisites for ultrasound use during running. We aimed to assess (i) the effect of wearing an ultrasound transducer on running pattern and (ii) the test–retest reliability of MTJ tracking during running. Sixteen long-distance runners (nine injury-free, seven with Achilles tendinopathy) ran at different speeds on an instrumented treadmill with a 10-camera system tracking skin-mounted retroreflective markers, first without and then with an ultrasound transducer attached to the lower leg to track the MTJ of the gastrocnemius medialis. Spatiotemporal parameters, joint kinematics and kinetics were compared between conditions using mixed ANOVAs and paired t-tests. MTJ tracking was performed manually twice by three raters in ten participants. Variability and standard error of measurement (SEM) quantified the inter- and intra-tester test–retest reliability. The running pattern was not affected by wearing the ultrasound transducer, except for significantly less knee flexion during midstance (1.6°) and midswing (2.9°) found when wearing the transducer. Inter-rater and intra-rater SEMs for MTJ tracking to assess the tendon strain (0.43%, and 0.56%, respectively) were about four times as low as between-group differences presented in literature. The minimal effects found on the running pattern and acceptable test–retest reliability indicates that dynamic ultrasound during running can be appropriately used to study Achilles tendon mechanics and thereby help improve our understanding of Achilles tendon behavior during running, injury development and recovery.

Kinematical Effects of a Mandibular Advancement Occlusal Splint on Running until Exhaustion at Severe Intensity.

The effects of occlusal splints on sport performance have already been studied, although their biomechanical impacts are often overlooked. We investigated the kinematical changes during running until exhaustion at severe intensity while wearing a mandibular advancement occlusal splint. Twelve trained runners completed (i) an incremental protocol on a track to determine their velocity corresponding to maximal oxygen uptake and (ii) two trials of square wave transition exercises at their velocity corresponding to maximal oxygen until exhaustion, wearing two occlusal splints (without and with mandibular advancement). Running kinematics were compared within laps performed during the square wave transition exercises and between splint conditions. The mandibular advancement occlusal splint increased the running distance covered (~1663 ± 402 vs. 1540 ± 397 m, p = 0.03), along with a noticeable lap effect in decreasing stride frequency (p = 0.04) and increasing stride length (p = 0.03) and duty factor (p < 0.001). No spatiotemporal differences were observed between splints, except for improved balance foot contact times in the mandibular advancement condition. An increased knee flexion angle at initial contact (p = 0.017) was noted along laps in the non-advancement condition, despite the fact that no differences between splints were found. Running patterns mainly shifted within laps rather than between conditions, indicating that a mandibular advancement occlusal splint had a trivial kinematical effect.

Clustering Runners' Response to Different Midsole Stack Heights: A Field Study.

Advanced footwear technology featuring stack heights higher than 30 mm has been proven to improve running economy in elite and recreational runners. While it is understood that the physiological benefit is highly individual, the individual biomechanical response to different stack heights remains unclear. Thirty-one runners performed running trials with three different shoe conditions of 25 mm, 35 mm, and 45 mm stack height on an outdoor running course wearing a STRYD sensor. The STRYD running variables for each participant were normalized to the 25 mm shoe condition and used to cluster participants into three distinct groups. Each cluster showed unique running patterns, with leg spring stiffness and vertical oscillation contributing most to the variance. No significant differences were found between clusters in terms of body height, body weight, leg length, and running speed. This study indicates that runners change running patterns individually when running with footwear featuring different stack heights. Clustering these patterns can help understand subgroups of runners and potentially support running shoe recommendations.

Strategic insights into penalty kick execution: A comprehensive analysis of observable behaviors in the German Bundesliga

This study aimed to investigate which observable variables would be able to predict the penalty taker strategy; and to identify the prevalence of the penalty taker strategy in successful penalty kicks. Dataset consists of 220 penalty kicks from the German Bundesliga (2019-2021). Video-based performance analysis of in-match penalty kicks was performed. Chi-squared (χ2) test and logistic regression (enter method) analyses were performed to investigate the relationship between observable behaviors and the penalty-taker strategy. The following behavior: gaze behavior at the ball, no deception, number of steps more than 3, perceived ball speed as powerful shot, run up speed fast, penalty kick shot height at the center or down, kicking technique instep kick, and run up approach frontal was related to the goalkeeper independent strategy (χ2 (177) = 211.049, 96%, p &lt; .001). In successful penalty kicks the independent goalkeeper strategy was more adopted (59.87%). The differentiation between penalty kick patterns provides scientific and practical insights as it enables researchers to identify patterns in the German Bundesliga. Through analysis of the kicker's running pattern, deception actions, gaze behavior, and kicking technique, football practitioners may attempt to determine the kicker's favored approach, and ultimately the penalty kick strategy, so they can inform coaching staff and players.

Bilateral Asymmetry of Spatiotemporal Running Gait Parameters in U14 Athletes at Different Speeds.

The assessment of leg asymmetries is gaining scientific interest due to its potential impact on performance and injury development. Athletes around puberty exhibit increased gait variability due to a non-established running pattern. This study aims to describe the asymmetries in the spatiotemporal running parameters in developmentally aged athletes. Forty athletes under 14 (U14) (22 females and 18 males) were assessed running on a treadmill at constant speeds of 12 and 14 km·h-1 for 3 min. Step length, step frequency, along with contact (CT) and flight time, both in absolute values and as a percentage of step time, were recorded using a RunScribe sensor attached to the laces of each shoe. U14 runners exhibited high bilateral symmetry in the spatiotemporal parameters of running, with mean asymmetry values (1-5.7%) lower than the intra-limb coefficient of variation (1.7-9.6%). Furthermore, bilateral asymmetries did not vary between the two speeds. An individual-based interpretation of asymmetries identified subjects with consistent asymmetries at both speeds, particularly in terms of CT and contact ratio (%, CT/step time). This study confirms the high symmetry of pubertal runners and paves the way for the application of portable running assessment technology to detect asymmetries on an individual basis.

Social jet lag impairs exercise volume and attenuates physiological and metabolic adaptations to voluntary exercise training.

Social jet lag (SJL) is a misalignment between sleep and wake times on workdays and free days. SJL leads to chronic circadian rhythm disruption and may affect nearly 70% of the general population, leading to increased risk for cardiometabolic diseases. This study investigated the effects of SJL on metabolic health, exercise performance, and exercise-induced skeletal muscle adaptations in mice. Ten-week-old C57BL/6J mice (n = 40) were allocated to four groups: control sedentary (CON-SED), control exercise (CON-EX), social jet lag sedentary (SJL-SED), and social jet lag exercise (SJL-EX). CON mice were housed under a 12:12-h light-dark cycle. SJL was simulated by implementing a 4-h phase delay for 3 days to simulate "weekends," followed by a 4-h phase advance back to "weekdays," for 6 wk. EX mice had free access to a running wheel. Graded exercise tests (GXTs) and glucose tolerance tests (GTTs) were performed at baseline and after intervention to monitor the effects of exercise and social jet lag on cardiorespiratory and metabolic health, respectively. SJL led to alterations in activity and running patterns and clock gene expression in skeletal muscle and decreased average running distance (P < 0.05). SJL-SED mice gained significantly more weight compared with CON-SED and SJL-EX mice (P < 0.01). SJL impaired fasting blood glucose and glucose tolerance compared with CON mice (P < 0.05), which was partially restored by exercise in SJL-EX mice. SJL also blunted improvements in exercise performance and mitochondrial content in the quadriceps. These data suggest that SJL blunted some cardiometabolic adaptations to exercise and that proper circadian hygiene is necessary for maintaining health and performance.NEW & NOTEWORTHY In mice, disrupting circadian rhythms with social jet lag for 6 wk caused significant weight gain, higher fasting blood glucose, and impaired glucose tolerance compared with control. Voluntary exercise in mice experiencing social jet lag prevented weight gain, though the mice still experienced increased fasting blood glucose and impaired exercise performance compared with trained mice not experiencing social jet lag. Social jet lag seems to be a potent circadian rhythm disruptor that impacts exercise-induced training adaptations.

Brody Disease, an Early-Onset Myopathy With Delayed Relaxation and Abnormal Gait: A Case Series of 9 Children.

Brody disease is a rare autosomal recessive myopathy, caused by pathogenic variants in the ATP2A1 gene. It is characterized by an exercise-induced delay in muscle relaxation, often reported as muscle stiffness. Children may manifest with an abnormal gait and difficulty running. Delayed relaxation is commonly undetected, resulting in a long diagnostic delay. Almost all published cases so far were adults with childhood onset and adult diagnosis. With diagnostic next-generation sequencing, an increasing number of patients are diagnosed in childhood. We describe the clinical and genetic features of 9 children from 6 families with Brody disease. All presented with exercise-induced delayed relaxation, reported as difficulty running and performing sports. Muscle strength and mass was normal, and several children even had an athletic appearance. However, the walking and running patterns were abnormal. The diagnostic delay ranged between 2 and 7 years. Uniformly, a wide range of other disorders were considered before genetic testing was performed, revealing pathogenic genetic variants in ATP2A1. To conclude, this case series is expected to improve clinical recognition and timely diagnosis of Brody disease in children. We propose that ATP2A1 should be added to gene panels for congenital myopathies, developmental and movement disorders, and muscle channelopathies.

Development and implementation of a Dependable, Simple, and Cost-effective (DSC), open-source running wheel in High Drinking in the Dark and Heterogeneous Stock/Northport mice.

Maintaining healthy and consistent levels of physical activity (PA) is a clinically proven and low-cost means of reducing the onset of several chronic diseases and may provide an excellent strategy for managing mental health and related outcomes. Wheel-running (WR) is a well-characterized rodent model of voluntary PA; however, its use in biomedical research is limited by economical and methodical constraints. Here, we showcase the DSC (Dependable, Simple, Cost-effective), open-source running wheel by characterizing 24-h running patterns in two genetically unique mouse lines: inbred High Drinking in the Dark line 1 [iHDID-1; selectively bred to drink alcohol to intoxication (and then inbred to maintain phenotype)] and Heterogeneous Stock/Northport (HS/Npt; the genetically heterogeneous founders of iHDID mice). Running distance (km/day), duration (active minutes/day) and speed (km/hour) at 13-days (acute WR; Experiment 1) and 28-days (chronic WR; Experiment 2) were comparable to other mouse strains, suggesting the DSC-wheel reliably captures murine WR behavior. Analysis of 24-h running distance supports previous findings, wherein iHDID-1 mice tend to run less than HS/Npt mice in the early hours of the dark phase and more than HS/Npt in the late hours of dark phase/early light phase. Moreover, circadian actograms were generated to highlight the broad application of our wheel design across disciplines. Overall, the present findings demonstrate the ability of the DSC-wheel to function as a high-throughput and precise tool to comprehensively measure WR behaviors in mice.

Hamstring muscle injury is preceded by a short period of higher running demands in professional football players.

The aim of this study was to examine match running patterns before a hamstring muscle injury occurs during a match in male professional football players. A total of 281 male professional football players belonging to 7 teams from LaLiga were prospectively monitored over three seasons. Among these, 36 players suffered a non-contact hamstring muscle injury during an official match. The injuries were recorded by the medical staff, including the minute when the injury occurred. Running distances at different speed thresholds for 5 min and 15 min before the injury were compared to mean values of the previous 5 matches for the same time points. There were a total of 44 non-contact hamstring muscle injuries, which represents a hamstring muscle injury incidence of 3.34 injuries/1000 h of match exposure. The average time loss for these injuries was 33 ± 28 days (range 7 to 117 days). In the 15 min prior to the injury, players ran a similar distance as in control matches (p from 0.22 to 0.08). However, players ran a greater distance in the 5-min period before the injury than in control matches at 21.0-23.9 km/h (p < 0.001) and at ≥ 24 km/h (p < 0.001). The odds ratio for a hamstring muscle injury was 7.147 for those players who ran > 30.0 m at ≥ 21 km/h in a 5-min period (p < 0.001). Hamstring muscle injuries during competition were preceded by 5 min of higher running demands at > 21 km/h, compared with control matches. This suggests that a short period of unusual running increases the risk of hamstring muscle injury in professional football players.

The Impact of Excessive Body Weight and Foot Pronation on Running Kinetics: A Cross-Sectional Study

BackgroundRunning exercise is an effective means to enhance cardiorespiratory fitness and body composition. Besides these health benefits, running is also associated with musculoskeletal injuries that can be more prevalent in individuals with excessive body weight. Little is known regarding the specific effects of overweight and foot pronation on ground reaction force distribution during running. Therefore, this study aimed to investigate the effects of overweight/obesity and foot pronation on running kinetics.MethodsEighty-four young adults were allocated to four experimental groups: non-excessive body weight/non-pronated feet; non-excessive body weight/pronated feet; overweight or obesity/ non-pronated feet and overweight or obesity/pronated feet. Biomechanical testing included participants to run at ~ 3.2 m/s over an 18-m walkway with an embedded force plate at its midpoint. Three-dimensional ground reaction forces were recorded and normalized to body mass to evaluate running kinetics from 20 running trials. Test–re-test reliability for running speed data demonstrated ICC > 0.94 for each group and in total.ResultsThe results indicated significantly lower vertical impact peak forces (p = 0.001, effect size = 0.12), shorter time to reach the vertical impact peak (p = 0.006, effect size = 0.08) and reduced vertical loading rate (p = 0.0007, effect size = 0.13) in individuals with excessive body weight (overweight or obesity/non-pronated feet group and overweight or obesity/pronated feet) compared with individuals non-excessive body weight (non-excessive body weight/non-pronated feet and non-excessive body weight/pronated feet). Moreover, the excessive body weight groups presented lower peak braking (p = 0.01, effect size = 0.06) and propulsion forces (p = 0.003, effect size = 0.09), lower medio-lateral loading rate (p = 0.0009, effect size = 0.12), and greater free moments (p = 0.01, effect size = 0.07) when compared to the non-overweight groups. Moreover, a significant body mass by foot pronation interaction was found for peak medio-lateral loading rate. Non-excessive body weight/pronated feet, excessive body weight/non-pronated feet and excessive body weight/pronation groups presented lower medio-lateral loading rates compared to non-excessive body weight/non-pronated feet (p = 0.0001, effect size = 0.13).ConclusionsOur results suggest that excessive body weight has an impact on ground reaction forces during running. We particularly noted an increase in medio-lateral and torsional forces during the stance phase. Individuals with excessive body weight appear to adapt their running patterns in an effort to attenuate early vertical impact loading.

Effect of three different running gait cues on vertical tibial acceleration

BackgroundRepetitive impacts during running are associated with some running injuries. Tibial acceleration is a proxy for tibial loading, and interventions that can decrease it are likely to be of interest to the running community. Research questionWhat effect do running gait cues have on peak vertical tibial acceleration at a comfortable and moderate running pace, and how will these cues be executed? MethodsTwenty-seven participants ran on a treadmill according to the following cues in random order: run softly and lightly, run with shorter steps, and increase preferred step rate by 7.5 %. Participants maintained each condition for one minute before returning to their ‘preferred’ running pattern for two minutes. Two tibia-mounted inertial measurement unit sensors were used to collect tibial acceleration data at a ‘comfortable’ and ‘moderate’ run pace. A repeated measures analysis of variance test was used to compare the means between running conditions. ResultsCompared to preferred running, the decrease step length (−8 %, p = 0.002, Cohen’s d=0.33) and run softly and lightly (−9 %, p = 0.040, Cohen’s d=0.38) cues provided a significant reduction in peak vertical tibial acceleration during a comfortable run pace. No significant difference was observed with an increase in step rate. Compared to preferred running, there was no significant difference in peak vertical tibial acceleration with any of the running gait cues during a moderate run pace. SignificanceInstructing runners to decrease step length or run softly and lightly can result in small reductions in peak vertical tibial acceleration during a comfortable run pace, but running gait cues during a moderate run pace provide no effects. Differences in the execution of each cue are likely to influence overall tibial loading throughout the stride cycle. These findings provide novel biomechanical evidence for the potential effects of running retraining strategies for reducing tibial accelerations at different running paces.

KeepRunning: A MoCap-Based Rapid Test to Prevent Musculoskeletal Running Injuries

The worldwide popularisation of running as a sport and recreational practice has led to a high rate of musculoskeletal injuries, usually caused by a lack of knowledge about the most suitable running technique for each runner. This running technique is determined by a runner’s anthropometric body characteristics, dexterity and skill. Therefore, this study aims to develop a motion capture-based running analysis test on a treadmill called KeepRunning to obtain running patterns rapidly, which will aid coaches and clinicians in assessing changes in running technique considering changes in the study variables. Therefore, a review and proposal of the most representative events and variables of analysis in running was conducted to develop the KeepRunning test. Likewise, the minimal detectable change (MDC) in these variables was obtained using test–retest reliability to demonstrate the reproducibility and viability of the test, as well as the use of MDC as a threshold for future assessments. The test–retest consisted of 32 healthy volunteer athletes with a running training routine of at least 15 km per week repeating the test twice. In each test, clusters of markers were placed on the runners’ body segments using elastic bands and the volunteers’ movements were captured while running on a treadmill. In this study, reproducibility was defined by the intraclass correlation coefficient (ICC) and MDC, obtaining a mean value of ICC = 0.94 ± 0.05 for all variables and MDC = 2.73 ± 1.16° for the angular kinematic variables. The results obtained in the test–retest reveal that the reproducibility of the test was similar or better than that found in the literature. KeepRunning is a running analysis test that provides data from the involved body segments rapidly and easily interpretable. This data allows clinicians and coaches to objectively provide indications for runners to improve their running technique and avoid possible injury. The proposed test can be used in the future with inertial motion capture and other wearable technologies.

Neovascularization restructuring patterns in diabetic patients with coronary in stent restenosis an in-vivo optical coherence tomography study

Abstract Background Patients with diabetes mellitus (DM) have an increased risk of in stent restenosis (ISR). Neovascularization (NV) is considered as a unique phathophysiological factor of ISR in diabetic patients. However, the structures of in vivo human coronary NV and their relationship with ISR, especially in diabetic patients remain unclear. In this study, we aimed to investigate the NV structure differentiation between patients with and without DM after coronary stent implantation using optical coherence tomography (OCT). Methods We included 136 patients with ISR (70 patients in DM group and 66 patients in non-DM group) who underwent optical coherence tomography during coronary angiography follow-up. NVs were manually segmented and three-dimensional (3D) rendering of OCT images was performed. NVs &amp;gt;1 mm were classified into longitudinal running and coral tree types according to their 3D structures. Results The popularity of the coral tree pattern NV in the DM group was 2.14-fold higher than in the non-DM group(p=0.012). 47.14% of patients in the DM group and 51.51% of patients in the non-DM group presented longitudinal NV (p = 0.610). The number of coral tree NV was relatively higher in DM patients than in the non-DM patients (p=0.019). However, the number of longitudinal NV showed no difference between the two group (p=0.872). The normalized NV volume of the DM group was significantly larger than the non-DM group (p=0.008). Normalized NV volume and DM were risk factors for coral tree NV formation in ISR lesions after adjustment for other factors. Conclusions NV with particular restructuring patterns, including longitudinal running and coral tree patterns, could be found in ISR lesions. NV with a coral tree pattern, which is leakier and more immature, is more frequently found in patients with DM. Accurate and feasible imaging modalities for NV might offer promising opportunities to evaluate NV and prevent progression of ISR in diabetic patients.Longitudinal running NV by OCT in neointA coral tree pattern NV in the non-calci

An Orientational Harvesting Occipital Artery Technique via far Lateral Approach: A Cadaveric Study

To provide further information on the identification of the occipital artery (OA) and suggest an improved approach to its anterograde dissection technique for harvesting. Six cadaveric specimens were prepared for surgical simulation, and the anterograde approach was used to harvest the OA; a hockey stick incision was made from the C2 spinous process through the nuchal ligament to the mastoid tip. By retracting the scalp flap from the posterior arch of C2 to the transverse process, the suboccipital triangle was reflected by a single myocutaneous flap from the inferior nuchal line. In addition, 70 head computed tomography angiography scans were assessed bilaterally (n= 140) to study the running pattern of the OA. The mean total length of the mobilized OA was 11.8 ± 0.7cm, with a diameter of 1.5 ± 0.1-2.1 ± 0.2mm at the suboccipital segment and 1.3 ± 0.1mm at the upper edge of the surgical incision. The average distance of OA at the inferior nuchal line to the midline was 2.9 ± 0.3cm, the average distance of OA at the superior nuchal line to midline was 4.1 ± 0.2cm, the average distance of OA at incision edge to midline was 5.2 ± 0.3cm. Orientational anterograde technique for OA harvesting is a fast and easy approach. This approach avoids critical neurovascular structures. The most important step is to identify the OA near the lateral edge of the superior oblique muscle. Subsequently, in conjunction with preoperative computed tomography angiography, an imaginary line that crosses the inferior and superior nuchal lines may be established to assist in the separation of theOA.

Rare case of single left coronary artery in a Japanese cadaver.

A single left coronary artery with a single orifice in the left aortic sinus was observed during anatomical practice in an 81-year-old male Japanese cadaver. The single left coronary artery bifurcated into the anterior interventricular branch (IVa) and circumflex (CXa) branches. The IVa descended into the anterior interventricular sulcus to supply the apex of the heart, leaving a branch that traversed the upper part of the infundibulum to supply the anterior upper region of the right ventricle. The CXa curved leftward in the atrioventricular sulcus to reach the posterior surface, after which it continued to emerge into the anterior surface. The vascular running pattern showed that CXa directly supplied blood to the upper right ventricle (but not the conus branch), with three branches connected to the apex. The atrial arteries showed no anomalous distribution patterns. These findings are useful during surgical procedures, including cardiac catheterization.

Instructions Promoting an External Focus Are More Effective for Altering Impact Forces in Female Runners.

Previous studies have found that instructions promoting an external focus (EF) tend to be more effective for movement pattern retraining compared to instructions promoting an internal focus (IF), for a variety of movement tasks. However, few studies have examined how different types of instructions affect running mechanics associated with running-related injury risk. Therefore, the purpose of this study was to compare the effects of instructions promoting different attentional foci on impact forces during running. Cross-sectional study. Twenty uninjured female recreational runners ran at a self-selected speed with their typical pattern (no instructions condition) on an instrumented treadmill that measured ground reaction forces. Next, they were given 2 sets of instructions intended to alter their running pattern; one promoted an IF and the other promoted an EF. Repeated-measures analysis of variance was used to compare impact peaks and loading rates across the conditions (no instructions, IF, and EF), with post hoc tests conducted in the case of a significant omnibus test. There were differences among the conditions in the impact peaks (P < .001) and loading rates (P < .001). Impact peaks were lower for the IF (P = .002) and EF (P < .001) conditions compared to the no instructions condition. Loading rates were lower for the EF condition compared to the no instructions (P < .001) and IF (P < .001) conditions; there was no difference between the IF and no instructions conditions (P = .24). Our findings indicate that instructions promoting an EF may be more effective at reducing loading rates during running compared to instructions promoting an IF. Clinicians should consider these findings when attempting to retrain a runner's running pattern.

Duty factor and stride frequency as (potential) load magnitude determinants of slow, female runners’ habitual running pattern

Duty factor and stride frequency as (potential) load magnitude determinants of slow, female runners’ habitual running pattern