scholarly journals Vertical ground reaction force analysis during gait with unstable shoes

2015 ◽  
Vol 28 (3) ◽  
pp. 459-466
Author(s):  
Giulia Pereira ◽  
Aluísio Otavio Vargas Avila ◽  
Rudnei Palhano

AbstractIntroduction Footwear is no longer just an accessory but also a protection for the musculoskeletal system, and its most important characteristic is comfort.Objectives This study aims to identify and to analyze the vertical ground reaction force in barefoot women and women with unstable shoes.Methodology Five women aged 25 ± 4 years old and mass of 50 ± 7 kg participated in this study. An AMTI force plate was used for data acquisition. The 10 trials for each situation were considered valid where the subject approached the platform with the right foot and at the speed of 4 km/h ± 5%. The instable shoe of this study is used in the practice of physical activity.Results The results showed that the first peak force was higher for the footwear situation, about 5% and significant differences between the barefoot and footwear situation. This significant difference was in the first and second peaks force and in the time of the second peak.Conclusion The values showed that the footwear absorbs approximately 45% of the impact during gait.

1992 ◽  
Vol 05 (02) ◽  
pp. 44-50 ◽  
Author(s):  
D. A. Hulse ◽  
H. A. Hogan ◽  
Margaret Slater ◽  
M. T. Longnecker ◽  
Susan Yanoff

SummaryThe purpose of this study was: to quantitate the peak vertical ground reaction force acting on the forelimbs of dogs as they landed after jumping an obstacle; to compare that force at three heights; and to evaluate factors that may affect vertical ground reaction force. Thirteen military working dogs were studied. A strain gauge force plate was used to measure force. Three measurements were recorded for each dog at each height. The means of the medians of the three forces for each dog at each height were compared using a repeated measures analysis of variance. Mean force at 63 cm was 986.9 ± 221.5 N, mean force at 79 cm was 1175.0 ±227.4 N, and mean force at 94 cm was 1366.1± 268.5 N. There was a significant difference in mean force at the three jump heights (p = 0.0002). The significance was unchanged when force was normalized for body weight. Statistical models were used to evaluate the effect of other independent variables. Factors that were found to effect force were body weight, breed, and sex of the dog. Further studies are needed to determine the clinical significance of these findings.Vertical ground reaction force was measured in thirteen dogs landing on a force plate after jumping an obstacle. Three readings were taken for each dog at each of three heights, and the mean vertical ground reaction force was compared. Force readings were significantly different at each height, increasing as height increased. Factors that were found to effect vertical ground reaction force were body weight, breed, and sex.


2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0020 ◽  
Author(s):  
Irene Davis ◽  
Todd Hayano ◽  
Adam Tenforde

Category: Other Introduction/Purpose: While the etiology of injuries is multifactorial, impact loading, as measured by the loadrate of the vertical ground reaction force has been implicated. These loadrates are typically measured with a force plate. However, this limits the measure of impacts to laboratory environments. Tibial acceleration, another measure of running impacts, is considered a surrogate for loadrate. It can be measured using new wearable technology that can be used in a runner’s natural environment. However, the correlation between tibial acceleration measured from mobile devices and vertical ground reaction force loadrates, measured from forceplates, is unknown. The purpose of this study was to determine the correlation between vertical and resultant loadrates to vertical and resultant tibial acceleration across different footstrike patterns (FSP) in runners. Methods: The study involved a sample of convenience made up of 169 runners (74 F, 95 M; age: 38.66±13.08 yrs) presenting at a running injury clinic. This included 25 habitual forefoot strike (FFS), 17 midfoot strike (MFS) and 127 rearfoot strike (RFS) runners. Participants ran on an instrumented treadmill (average speed 2.52±0.25 m/s), with a tri-axial accelerometer attached at the left distal medial tibia. Only subjects running with pain <3/10 on a VAS scale during the treadmill run were included to reduce the confounding effect of pain. Vertical average, vertical instantaneous and resultant instantaneous loadrates (VALR, VILR and RILR) and peak vertical and resultant tibial accelerations (VTA, RTA) were averaged for 8 consecutive left steps. Correlation coefficients (r) were calculated between tibial accelerations and loadrates. Results: All tibial accelerations were significantly correlated across all loadrates, with the exception of RTA with VILR for FFS (Table 1) which was nearly significant (p=0.068). Correlations ranged from 0.37-0.82. VTA was strongly correlated with all loadrates (r = 0.66). RTA was also strongly correlated with both loadrates for RFS and MFS, but only moderately correlated with loadrates for FFS (r = 0.47). Correlations were similar across the different loadrates (VALR, VILR, RILR). Conclusion: The stronger correlation between vertical tibial acceleration and all loadrates (VALR, VILR, RILR) suggests that it may be the best surrogate for loadrates when studying impact loading in runners.


2019 ◽  
Vol 47 (4) ◽  
pp. 968-973 ◽  
Author(s):  
J.J. Hannigan ◽  
Christine D. Pollard

Background: A recent study suggested that maximal running shoes may increase the impact force and loading rate of the vertical ground-reaction force during running. It is currently unknown whether runners will adapt to decrease the impact force and loading rate over time. Purpose: To compare the vertical ground-reaction force and ankle kinematics between maximal and traditional shoes before and after a 6-week acclimation period to the maximal shoe. Study Design: Controlled laboratory study. Methods: Participants ran in a traditional running shoe and a maximal running shoe during 2 testing sessions 6 weeks apart. During each session, 3-dimensional kinematics and kinetics were collected during overground running. Variables of interest included the loading rate, impact peak, and active peak of the vertical ground-reaction force, as well as eversion and dorsiflexion kinematics. Two-way repeated measures analyses of variance compared data within participants. Results: No significant differences were observed in any biomechanical variable between time points. The loading rate and impact peak were higher in the maximal shoe. Runners were still everted at toe-off and landed with less dorsiflexion, on average, in the maximal shoe. Conclusion: Greater loading rates and impact forces were previously found in maximal running shoes, which may indicate an increased risk of injury. The eversion mechanics observed in the maximal shoes may also increase the risk of injury. A 6-week transition to maximal shoes did not significantly change any of these measures. Clinical Relevance: Maximal running shoes are becoming very popular and may be considered a treatment option for some injuries. The biomechanical results of this study do not support the use of maximal running shoes. However, the effect of these shoes on pain and injury rates is unknown.


Author(s):  
Chi-Yin Tse ◽  
Hamid Nayeb-Hashemi ◽  
Ashkan Vaziri ◽  
Paul K. Canavan

A single-leg landing is a common type of high-risk maneuver performed by athletes. The majority of anterior cruciate ligament injury is accounted for by non-contact mechanisms, such as single-leg landings. The purpose of this study was to develop a subject specific single-leg drop landing to analyze the kinematics and kinetics of two different types of landings. Kinematic data was analyzed at five points during the landing phase: initial contact (IC), peak vertical ground reaction force (pVGRF), peak joint reaction force (pJRF), maximum knee flexion (MKF), and maximum valgus angle (MFP). A linear relationship was noted in comparing the average maximum peak vertical ground reaction force, average maximum knee flexion, and average maximum valgus angle to the platform heights in both landing styles. An increase in platform height was directly related to increased knee valgus angle in both landing styles. Significant difference (p < 0.05) was noted in the peak vertical ground reaction force between the 60% and 80% platform heights, as well as between 60% and 100% with arms above. Landing with arms across the body yielded more significant difference (p < 0.05) between platform heights in both frontal and sagittal planes. However, comparing both landing styles to each other only yielded significant difference (p < 0.05) at the 100% platform height. A valgus-varus-valgus movement was observed in all landings, and is a probable contributor to single-leg landing ACL ruptures.


2000 ◽  
Vol 16 (2) ◽  
pp. 210-218 ◽  
Author(s):  
Dorsey S. Williams ◽  
Irene S. McClay ◽  
Kurt T. Manal

Runners are sometimes advised to alter their strike pattern as a means of increasing performance or in response to injury. The purpose of this study was to compare lower extremity mechanics of rearfoot strikers (RFS), who were instructed to run with a forefoot strike pattern (CFFS) to those of a preferred forefoot striker (FFS). Three-dimensional mechanics of 9 FFS and 9 CFFS were evaluated. Peak values for most kinematic and kinetic variables and all patterns of movement were not found to be statistically different between CFFS and FFS. Only peak vertical ground reaction force and peak ankle plantarflexion moment were found to be significantly lower (p ≤ .05) in the CFFS group. This suggests that RFS are able to assume a FFS pattern with very little practice that is very similar to that of a preferred FFS. The impact of changing one's strike pattern on injury risk and running performance needs further study.


Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4345 ◽  
Author(s):  
Xianta Jiang ◽  
Christopher Napier ◽  
Brett Hannigan ◽  
Janice J. Eng ◽  
Carlo Menon

The vertical ground reaction force (vGRF) and its passive and active peaks are important gait parameters and of great relevance for musculoskeletal injury analysis and prevention, the detection of gait abnormities, and the evaluation of lower-extremity prostheses. Most currently available methods to estimate the vGRF require a force plate. However, in real-world scenarios, gait monitoring would not be limited to a laboratory setting. This paper reports a novel solution using machine learning algorithms to estimate the vGRF and the timing and magnitude of its peaks from data collected by a single inertial measurement unit (IMU) on one of the lower limb locations. Nine volunteers participated in this study, walking on a force plate-instrumented treadmill at various speeds. Four IMUs were worn on the foot, shank, distal thigh, and proximal thigh, respectively. A random forest model was employed to estimate the vGRF from data collected by each of the IMUs. We evaluated the performance of the models against the gold standard measurement of the vGRF generated by the treadmill. The developed model achieved a high accuracy with a correlation coefficient, root mean square error, and normalized root mean square error of 1.00, 0.02 body weight (BW), and 1.7% in intra-participant testing, and 0.97, 0.10 BW, and 7.15% in inter-participant testing, respectively, for the shank location. The difference between the reference and estimated passive force peak values was 0.02 BW and 0.14 BW with a delay of −0.14% and 0.57% of stance duration for the intra- and inter-participant testing, respectively; the difference between the reference and estimated active force peak values was 0.02 BW and 0.08 BW with a delay of 0.45% and 1.66% of stance duration for the intra- and inter-participant evaluation, respectively. We concluded that vertical ground reaction force can be estimated using only a single IMU via machine learning algorithms. This research sheds light on the development of a portable wearable gait monitoring system reporting the real-time vGRF in real-life scenarios.


2017 ◽  
Vol 6 (1) ◽  
pp. 1398
Author(s):  
R. Raja ◽  
H. Ravindranath Rai ◽  
J. N. Sridharamurthy ◽  
B. Madhouraj ◽  
R. Balaji ◽  
...  

<p><strong>Background</strong>: Proper prescription of prosthetic device and potential rehabilitation increases the quality of life for subjects with amputations.</p><p><strong>Objective</strong>: To compare the effect of vertical ground reaction force (Fz) on unilateral Transtibial amputees those who are using conventional and modular patellar tendon bearing (PTB) prosthesis with stump exercises.</p><p><strong>Material and Methodology</strong>: A sample of 120 persons with below knee amputees who were trained to wear prosthesis were studied with an comparative follow up study design with purposive sampling technique. The 120 adult amputee patients were divided in to two groups having 60 samples in each group, group A patients were given conventional patellar tendon bearing (PTB) prosthesis with intensive stump exercises and group B patients were given modular PTB prosthesis with intensive stump exercises respectively. Data analyzed statistically.</p><p><strong>Results</strong>: The unilateral transtibial amputees who trained with modular prosthesis along with stump exercises group patients Fz-force in newton were increased as compared to the unilateral transtibial amputees who were trained with conventional PTB prosthesis along with stump exercises. There was no significant difference seen in both the groups while giving stump exercises alone.</p><p><strong>Conclusion</strong>: The unilateral transtibial amputees who were trained with modular PTB prosthesis along with stump exercises group patient's Fz-force in newton (VGRF) has increased drastically compared with conventional PTB prosthesis.</p>


2019 ◽  
Vol 126 (5) ◽  
pp. 1315-1325 ◽  
Author(s):  
Andrew B. Udofa ◽  
Kenneth P. Clark ◽  
Laurence J. Ryan ◽  
Peter G. Weyand

Although running shoes alter foot-ground reaction forces, particularly during impact, how they do so is incompletely understood. Here, we hypothesized that footwear effects on running ground reaction force-time patterns can be accurately predicted from the motion of two components of the body’s mass (mb): the contacting lower-limb (m1 = 0.08mb) and the remainder (m2 = 0.92mb). Simultaneous motion and vertical ground reaction force-time data were acquired at 1,000 Hz from eight uninstructed subjects running on a force-instrumented treadmill at 4.0 and 7.0 m/s under four footwear conditions: barefoot, minimal sole, thin sole, and thick sole. Vertical ground reaction force-time patterns were generated from the two-mass model using body mass and footfall-specific measures of contact time, aerial time, and lower-limb impact deceleration. Model force-time patterns generated using the empirical inputs acquired for each footfall matched the measured patterns closely across the four footwear conditions at both protocol speeds ( r2 = 0.96 ± 0.004; root mean squared error  = 0.17 ± 0.01 body-weight units; n = 275 total footfalls). Foot landing angles (θF) were inversely related to footwear thickness; more positive or plantar-flexed landing angles coincided with longer-impact durations and force-time patterns lacking distinct rising-edge force peaks. Our results support three conclusions: 1) running ground reaction force-time patterns across footwear conditions can be accurately predicted using our two-mass, two-impulse model, 2) impact forces, regardless of foot strike mechanics, can be accurately quantified from lower-limb motion and a fixed anatomical mass (0.08mb), and 3) runners maintain similar loading rates (ΔFvertical/Δtime) across footwear conditions by altering foot strike angle to regulate the duration of impact. NEW & NOTEWORTHY Here, we validate a two-mass, two-impulse model of running vertical ground reaction forces across four footwear thickness conditions (barefoot, minimal, thin, thick). Our model allows the impact portion of the impulse to be extracted from measured total ground reaction force-time patterns using motion data from the ankle. The gait adjustments observed across footwear conditions revealed that runners maintained similar loading rates across footwear conditions by altering foot strike angles to regulate the duration of impact.


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