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Background While previous research has assessed running kinematics for age-related differences that could increase the risk of a running-related injury, none of these studies have included high school aged runners or assessed running kinematics using 2-dimensional video analysis. Purpose The purpose of this study was to compare sagittal plane kinematics during treadmill running in high school cross-country and young adult recreational runners using 2-dimensional motion analysis techniques. Methods Twenty-five high school cross-country runners (13 women, 12 men) and 25 young adult recreational runners (12 women, 13 men) consented to participate in this study. Reflective markers were placed on each lower extremity over multiple anatomical landmarks. After a five-minute acclimation period in which the participants ran on a treadmill at their preferred running speed, video data were recorded at 240 frames per second for all participants while they continued to run on the treadmill. Results There were no significant differences between left and right extremities. The young adult recreational runners exhibited significantly greater vertical excursion of the center of mass (t = 4.64, p = .0001) compared to the high school runners. There was no significant difference between the two age groups regarding the six other sagittal plane variables. Conclusions The young adult recreational runners demonstrated an increased center-of-mass vertical excursion in comparison to high school cross-country runners. In addition, the results obtained in this study for kinematic variables using 2-dimensional motion analysis were similar to previously reported studies using 3-dimensional motion analysis, demonstrating that 2-dimensional motion analysis could be used for analyzing sagittal plane running kinematics in clinical settings. Level of Evidence 4, Controlled laboratory study [ABSTRACT FROM AUTHOR]

Background: Variations in vertical loading rates have been associated with overuse injuries of the lower extremity; however, they are typically collected using 3-dimensional motion capture systems and in-ground force plates not available to most clinicians because of cost and space constraints. Purpose: The purpose of this study was to determine if kinetic measures commonly used to describe lower extremity loading characteristics could be estimated from step rate and specific sagittal plane kinematic variables captured using 2-dimensional motion analysis during treadmill running. Study Design: Observational Study Methods: Ten high school cross-country runners (4 men and 6 women) voluntarily consented to participate in this study. Reflective markers were placed on each lower extremity over multiple anatomical landmarks. Participants were then asked to run on the instrumented treadmill at their preferred running speed. When the participants indicated they were in their typical running pattern, they continued to run at their preferred speed for a minimum of five minutes. After three minutes of running at their preferred running speed, the participant's step rate was counted and after running for four minutes, video and ground reaction force data were recorded for 60 sec. All running motion data were recorded using a single high-speed camera at 240 frames per second and ground reaction force data were sampled at 1000 Hz. Results: Mean kinematic values between the left and right extremities for all 10 participants were not significantly different. Consequently, data for the left and right extremities were grouped for all further analyses. The stepwise forward regression to predict vertical ground reaction force resulted in a five-variable model (step rate and four kinematic variables) with R² = 0.56. The stepwise forward regression to predict average loading rate also resulted in a five kinematic variable model with R² = 0.51. Conclusions: Step rate and sagittal plane kinematic variables measured using a simplified 2-dimensional motion analysis approach with a single high-speed camera can provide the clinician with a reasonable estimate of ground reaction force kinetics during treadmill running. Level of Evidence: 4, Controlled laboratory study [ABSTRACT FROM AUTHOR]

Background: For those runners who utilize footwear and have a rearfoot strike pattern, the durability of the midsole heel region has been shown to deteriorate as shoe mileage increases. Purpose: The purpose of this study was threefold: 1) to determine if the runner can self-report changes in heel cushioning properties of the midsole after an extended period of distance running, 2) to determine if force and plantar pressures measured in the heel region of the midsole using a capacitance sensor insole change after running 640 km, and 3) to determine if a durometer could be used clinically to objectively measure changes in the hardness of the material in the heel region of the midsole. Study Design: Cross-sectional Study Methods: Fifteen recreational runners voluntarily consented to participate and were provided with a new pair of running shoes. Each participant's running style was observed and classified as having a rearfoot strike pattern. Inclusion criteria included running at least 24 km per week, experience running on a treadmill, no history of lower extremity congenital or traumatic deformity, or acute injury six months prior to the start of the study. The ability of each participant to self-perceive changes in shoe cushioning, comfort and fit was assessed using the Footwear Comfort Assessment Tool (FCAT). In-shoe plantar pressures and vertical forces were assessed using a capacitance sensor insole while runners ran over a 42-meter indoor runway. A Shore A durometer was used to measure the hardness of the midsole in the heel region. All measures were completed at baseline (zero km) and after running 160, 320, 480, and 640 km. In addition to descriptive statistics, a repeated measures analysis of variance was used to determine if the FCAT, pressures, forces, or midsole hardness changed because of increased running mileage. Result: While plantar pressures and vertical forces were significantly reduced in the midsole heel region, none of the runners self-reported a significant reduction in heel cushioning based on FCAT scores after running 640 km. The use of a durometer provided an objective measure of the changes in the heel region of the midsole that closely matched the reductions observed in pressure and force values. Conclusion: The results indicated that runners who have a rearfoot strike pattern will have a 16% to 33% reduction in the amount of cushioning in the heel region of the midsole after running 480 km. Although there were significant reductions in heel cushioning, the experienced recreational runners in this study were not able to self-perceive these changes after running 640 km. In addition, the use of a durometer provides a quick and accurate way to assess changes in the hardness of the heel region of the midsole as running mileage increases. Level of Evidence: 3, Controlled laboratory study [ABSTRACT FROM AUTHOR]

Background: Clinicians are interested in the foot strike pattern (FSP) in runners because of the suggested relationship between the strike pattern and lower extremity injury. Purpose: The purpose of this study was to assess the ability of collegiate cross-country runners and recreational runners to self-report their foot strike pattern during running. Study Design: Cross-sectional Study Methods: Twenty-three collegiate cross-country and 23 recreational runners voluntarily consented to participate. Inclusion criteria included running at least 18 miles per week, experience running on a treadmill, no history of lower extremity congenital or traumatic deformity, or acute injury three months prior to the start of the study. All participants completed a pre-test survey to indicate their typical foot strike pattern during a training run (FSPSurvey). Prior to running, reflective markers were placed on the posterior midsole and the vamp of the running shoe. A high-speed camera was used to film each runner in standing and while running at his or her preferred speed on a treadmill. The angle between the vector formed by the two reflective markers and the superior surface of the treadmill was used to calculate the foot strike angle (FSA). To determine the foot strike pattern from the video data (FSPVideo), the static standing angle was subtracted from the FSA at initial contact of the shoe on the treadmill. In addition to descriptive statistics, percent agreement and Chi square analysis was used to determine distribution differences between the video analysis results and the survey. Results: The results of the chi-square analysis on the distribution of the FSPSurvey in comparison to the FSPVideo were significantly different for both the XCRunners (p < .01; Chi-square = 8.77) and the REC Runners (p < .0002; Chi-square = 16.70). The cross-country and recreational runners could correctly self-identified their foot strike pattern 56.5% and 43.5% of the time, respectively. Conclusion: The findings of this study suggest that the clinician cannot depend on an experienced runner to correctly self-identify their FSP. Clinicians interested in knowing the FSP of a runner should consider performing the two-dimensional video analysis described in this paper. Level of Evidence: 3 [ABSTRACT FROM AUTHOR]

Background: The posture of the foot has been implicated as a factor in the development of running-related injuries. A static measure of foot posture, such as the longitudinal arch angle (LAA), that can be easily performed and is predictive of the posture of the foot at midsupport while running could provide valuable information to enhance the clinician's overall evaluation of the runner. Purpose: The purpose of this study was to determine if the LAA, assessed in relaxed standing, could predict the posture of the foot at midsupport while running on a treadmill. Study Design: Cross-sectional Study Methods: Forty experienced runners (mean age 26.6 years) voluntarily consented to participate. Inclusion criteria included running at least 18 miles per week, previous experience running on a treadmill, no history of lower extremity congenital or traumatic deformity, or acute injury three months prior to the start of the study. Each runner had markers placed on the medial malleolus, navicular tuberosity, and medial aspect 1st metatarsal head of both feet. A high speed camera (240 Hz) was used to film both feet of each runner in standing and while running on a treadmill at their preferred speed. The LAA in standing and at mid-support while running was determined by angle formed by two lines drawn between the three markers with the navicular tuberosity serving as the apex. The LAA in midsupport was determined using the mean of the middle five running trials. Results: The levels of intra-rater and inter-rater reliability for the dynamic LAA were excellent. The results of the t-tests indicated that mean values between the left and right foot were not significantly different for the standing or running LAA. The results of the t-tests between male and female runners were also not significantly different for standing or running LAA. The Pearson correlation between standing and running LAA for all 80 feet was r = 0.95 (r² = 0.90). Conclusions: The standing LAA was found to be highly predictive of the running LAA at midsupport while running. Approximately 90% of the variance associated with foot posture at midsupport in running could be explained by the standing LAA. [ABSTRACT FROM AUTHOR]

Purpose/Background: No evidence exits regarding the magnitude of the change in foot posture following the “modified reverse-6” (MR6) taping procedure, either alone or in combination with the “low-dye” (LD) taping technique. The purpose of this study was to investigate the change in the height and width of the midfoot after application of the MR6 and the MR6 plus the LD (MR6+LD) taping technique and determine how long those changes last. Methods: Eleven individuals (2 female and 9 male) were recruited for this study and were tested under each of two experimental conditions, the MR6 and the MR6+LD taping technique. The order of testing for the two conditions was randomly determined. For each condition, the height and width of the midfoot at 50% of each subject's foot length was initially measured and then again immediately following the application of the tape. These measurements were repeated four hours later immediately prior to running two miles on a treadmill, again immediately after running, and finally after another four hours. Results: The dorsal arch height increased significantly with both the MR6 and MR6+LD taping, but only the MR6+LD remained statistically greater after four hours, a bout of exercise and again at the end of the day. The mean width of the midfoot significantly decreased with both taping procedures. The change in the width of the midfoot remained significantly decreased in both taping conditions after exercise and throughout the day. Conclusions: Both taping procedures are able to significantly change the height and width of the medial longitudinal arch of the foot, but the change lasted longer when the two taping procedures were combined. Levels of Evidence: Level 3, Prospective Cohort Study [ABSTRACT FROM AUTHOR]

Purpose/Background: Anti-pronation-taping utilizing both inelastic and elastic tape has been advocated to reduce pain and symptoms associated with excessive foot pronation. An important question regarding the use of taping is whether it can be applied consistently from one therapist to the next, from one session to the next or from one day to the next. Thus, the purpose of this study was to determine whether the “modified” Reverse-6 taping procedure using elastic tape could be applied to produce a consistent within-day and between-day change in the height and width of the medial longitudinal arch for a single clinician as well as between clinicians. A second purpose was to determine if the amount of general clinical experience influenced this consistency. Methods: Fifteen asymptomatic individuals (10 female and 5 male) with a mean age of 28.7 years were recruited to participate in this study. The height and width of the midfoot at 50% of each subject's foot length was measured in standing using a digital gauge and caliper. These measurements were done twice on the same day, on two different days and again by two clinicians with different levels of experience before and after having their feet taped using the “modified” Reverse-6 taping technique using elastic tape. Both clinicians received a one-hour training session on how to apply the taping technique and were also given a DVD showing the technique that they could review. In addition to descriptive statistics, intra-class correlation coefficients (ICC) were used to assess each clinician's within-day and between-day reliability. Between-clinician reliability was also determined. Results: The mean dorsal arch height and midfoot width before the application of tape was 62.7 and 78.9 mm. The mean dorsal arch height and width after the application of tape was 66.6 and 78.8 mm. The within-day reliability ICC(2,1) values for the two clinicians ranged from .865 to .991. The between-day reliability ICC(2,1) values for the two clinicians ranged from .874 to .985. The between-clinician reliability ICC(2,1) values ranged from .918 to .993. Conclusions: The results of this study indicate that the “modified” Reverse-6 foot taping technique using elastic tape can be used by more than one therapist for the same patient as well as from one session to the next with excellent reliability. Level of Evidence: Level 2, Prospective Cohort Study [ABSTRACT FROM AUTHOR]