scholarly journals Effect of Novel Spring Damper and Posterior Leaf Spring Ankle Foot Orthosis on the Vertical Component of Ground Reaction Forces During Walking in Patients With Drop Foot

2021 ◽  
Vol 8 (1) ◽  
pp. 17-22
Author(s):  
Ensieh Pourhosaingholi ◽  
◽  
Hassan Saeedi ◽  
Mohammad Kamali ◽  
◽  
...  
Keyword(s):  
Ground Reaction Force ◽  
Impact Force ◽  
Reaction Force ◽  
Vertical Component ◽  
Leaf Spring ◽  
Vertical Force ◽  
The Novel ◽  
Drop Foot ◽  
Vertical Ground Reaction Force ◽  
The Impact

Background: Ankle Foot Orthoses (AFOs) are often prescribed in patients with drop foot. The purpose of this study was to investigate the effect of the novel designed storing-restoring hybrid passive AFO versus Posterior Leaf Spring (PLS) AFO on the peak and timing of vertical component of ground reaction force (vGRF) in patients with drop foot. Objectives: the effect of novel designed storing-restoring hybrid passive AFO versus posterior leaf spring AFO on the peak and timing of Vertical Ground Reaction Force (vGRF) in drop foot patients. Methods: Ten adults with drop foot (7 males and 3 females) were included in this study. Then, these patients walked at a self-selected speed with two AFOs. For each trial, the vGRF components were obtained using a Kistler force plate. Results: the Independent t-test results showed a significant increase in the impact force in spring damper AFO than PLS (p<0.001). Significant differences were also found in the first and third peaks of vertical force and time of occurrence as well as the first minimum force and time of occurrence in spring damper than PLS AFO (p<0.001). Conclusion: the novel AFO affects not only the impact force and peak of vGRF but also the timing of these forces. These changes indicate an improvement in the overall performance of the novel AFO.

A 6-Week Transition to Maximal Running Shoes Does Not Change Running Biomechanics

2019 ◽  
Vol 47 (4) ◽  
pp. 968-973 ◽  
Author(s):  
J.J. Hannigan ◽  
Christine D. Pollard
Keyword(s):  
Ground Reaction Force ◽  
Loading Rate ◽  
Impact Force ◽  
Reaction Force ◽  
Vertical Ground Reaction Force ◽  
Risk Of Injury ◽  
Impact Peak ◽  
Running Shoes ◽  
Vertical Ground ◽  
The Impact

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.

Computational Methods Used in the Determination of Loading Rate: Experimental and Clinical Implications

1999 ◽  
Vol 15 (4) ◽  
pp. 404-417 ◽  
Author(s):  
C. Mark Woodard ◽  
Margaret K. James ◽  
Stephen P. Messier
Keyword(s):  
Difference Method ◽  
Ground Reaction Force ◽  
Loading Rate ◽  
Reaction Force ◽  
Vertical Force ◽  
Vertical Ground Reaction Force ◽  
Central Difference ◽  
Symptomatic Knee Osteoarthritis ◽  
Central Difference Method ◽  
Vertical Ground

Our purpose was to compare methods of calculating loading rate to the first peak vertical ground reaction force during walking and provide a rationale for the selection of a loading rate algorithm in the analysis of gait in clinical and research environments. Using vertical ground reaction force data collected from 15 older adults with symptomatic knee osteoarthritis and 15 healthy controls, we: (a) calculated loading rate as the first peak vertical force divided by the time from touchdown until the first peak; (b) calculated loading rate as the slope of the least squares regression line using vertical force and time as the dependent and independent variables, respectively; (c) calculated loading rate over discrete intervals using the Central Difference method; and (d) calculated loading rate using vertical force and lime data representing 20% and 90% of the first peak vertical force. The largest loading rate, which may be of greatest clinical importance, occurred when loading rates were calculated using the fewest number of data points. The Central Difference method appeared to maximize our ability to detect differences between healthy and pathologic cohorts. Finally, there was a strong correlation between methods, suggesting that all four methods are acceptable. However, if maximizing the chances of detecting differences between groups is of primary importance, the Central Difference method appears superior.

scholarly journals Pirouette Vertical Ground Reaction Force of Ballet Dancers and Non-Dancers

2020 ◽  
Vol 14 (2) ◽  
pp. 53-61
Author(s):  
Cynthia Hiraga ◽  
Camila Siriani ◽  
Paulo Ricardo Higassiaraguti Rocha ◽  
Débora Alves Souza ◽  
José Angelo Barela
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Vertical Force ◽  
Ballet Dancer ◽  
Vertical Ground Reaction Force ◽  
Ballet Dancers ◽  
Dance Training ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Initial Impulse

BACKGROUND: Different amounts of force are needed to produce an effective turn for the pirouette, especially vertical force. AIM: To examine the vertical force produced by the supporting leg during the execution of a pirouette en dehors of ballet dancer and non-dancer participants. METHOD: The participants included five ballet dancers who composed the ballet dancer group and eight girls without previous experience of dance training who composed the non-dancer group. The participants were invited to execute the pirouette en dehors on a force platform with each leg as the supporting leg. Two-way analyses of variance were used to test vertical reaction forces between the two groups over the preferred and non-preferred leg. RESULTS: Among the three vertical forces measured in the present study, the maximum vertical peak for the initial impulse was significantly higher for the ballet dancers compared to the non-dancer girls. The minimum vertical force and maximum vertical peak for the final impulse were similar between both groups. CONCLUSION: The results suggest that the initial vertical force may be critical to the pirouette en dehors, determining proficient execution of this movement in ballet dancers.

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
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Force Plate ◽  
Vertical Ground Reaction Force ◽  
Significant Difference ◽  
Vertical Ground ◽  
The Subject ◽  
Unstable Shoes ◽  
The Right ◽  
The Impact

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.

scholarly journals Biomechanical Effects of Flamenco Footwork

2021 ◽  
Vol 80 (1) ◽  
pp. 19-27
Author(s):  
Alfonso Vargas-Macías ◽  
Irene Baena-Chicón ◽  
Joanna Gorwa ◽  
Robert A. Michnik ◽  
Katarzyna Nowakowska-Lipiec ◽  
...  
Keyword(s):  
Knee Joint ◽  
Ground Reaction Force ◽  
Angular Displacement ◽  
Reaction Force ◽  
Force Plate ◽  
Vertical Component ◽  
Camera Motion ◽  
Vertical Ground Reaction Force ◽  
Knee Joint Kinematics ◽  
Basic Features

Abstract Footwork is one of the basic features of flamenco dancing and is performed in traditional high-heeled shoes. The purpose of this study was to analyse the mechanical profile of flamenco dancing in terms of vertical ground reaction force, and knee joint kinematics of the supporting limb in footwork technique in order to understand causes which predispose injuries derived from the practice of flamenco dancing. The participant in our study was a professional female flamenco dancer (34 years, 58 kg, 1.65 m) who performed the ZAP 3 test, a sequence of single strikes of the feet performed continuously for 15 s. 3D lower extremity kinematic data were collected using a five-camera motion analysis system (Vicon; Oxford Metrics Ltd., Oxford, UK). Ground reaction forces were recorded using a Kistler force plate. Our analysis was based on 30 cycles of each lower limb consisting of 177 footwork steps. The vertical component of the ground reaction force did not reveal any significant differences between the left and the right limb. The most dynamic strike was provided by the heel (twice the participant's body weight). The mean angular displacement of the supporting limb’s knee was ~27°. Results reveal that these impacts could make the knee joint more prone to injuries.

Lower Extremity Mechanics in Runners with a Converted Forefoot Strike Pattern

2000 ◽  
Vol 16 (2) ◽  
pp. 210-218 ◽  
Author(s):  
Dorsey S. Williams ◽  
Irene S. McClay ◽  
Kurt T. Manal
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Injury Risk ◽  
Reaction Force ◽  
Three Dimensional ◽  
Vertical Ground Reaction Force ◽  
Running Performance ◽  
Vertical Ground ◽  
The Impact

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.

Sensor insole for measuring temporal variables and vertical force during sprinting

2018 ◽  
Vol 232 (4) ◽  
pp. 369-374 ◽  
Author(s):  
Ryu Nagahara ◽  
Jean-Benoit Morin
Keyword(s):  
Pressure Sensor ◽  
Ground Reaction Force ◽  
Reaction Force ◽  
Force Platform ◽  
Vertical Force ◽  
Step Frequency ◽  
Vertical Ground Reaction Force ◽  
Temporal Variables ◽  
Reference Device ◽  
Vertical Ground

Temporal variables and vertical ground reaction force have been used as measures characterizing sprinting. A recently developed wireless pressure sensor insole (sensor insole) could be useful for monitoring sprinting in terms of temporal variables and vertical ground reaction force during training sessions. The purpose of this study was to examine the concurrent validity of the sensor insole for measuring temporal and vertical force variables during sprinting. One athlete performed five 50-m sprints, and the step-to-step vertical ground reaction force and plantar pressure were simultaneously measured by a long-force platform system (reference device) and the sensor insole, respectively. The temporal and vertical ground reaction force variables were calculated using signals from both devices, and a comparison was made between values obtained with both devices for 125 steps analyzed. The percentage bias, 95% limits of agreement, and Bland–Altman plots showed low agreement with the reference device for all variables except for step frequency. For the vertical ground reaction force variables, the sensor insole underestimated the values (−18.9 to −48.3%) compared to the force platform. While support time and time to maximal vertical force from the foot strike were overestimated by the sensor insole (54.6 ± 8.0% and 94.2 ± 23.2%), flight time was underestimated (−48.2 ± 15.0%). Moreover, t-test revealed the significant difference in all variables between the sensor insole and force platform, except for step frequency. The bias for step frequency (0.4 ± 7.5%) was small. However, there was heteroscedasticity for all variables. The results from this study demonstrate that a wireless pressure sensor insole is generally not valid to measure the temporal and vertical force variables during sprinting. Thus, using the examined sensor insole for monitoring sprinting characteristics is not recommended at this time.

Within-Day Accommodation Effects on Vertical Reaction Forces for Treadmill Running

2002 ◽  
Vol 18 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Scott C. White ◽  
Louise A. Gilchrist ◽  
Kathryn A. Christina
Keyword(s):  
Impact Force ◽  
Statistical Significance ◽  
Reaction Force ◽  
Dependent Measure ◽  
Treadmill Running ◽  
Repeated Measure ◽  
Vertical Force ◽  
Adaptation Period ◽  
Reaction Forces ◽  
The Impact

Prescribing an appropriate adaptation period is an important consideration when using treadmills for locomotion studies. The present study investigated within-trial accommodation to running on a force measuring treadmill. Force measures were derived from vertical reaction force records of 16 runners; 8 were experienced in running on a treadmill. Three dependent measures, the peak impact force (F1), the loading rate of the impact force (LR), and the peak active force (F2) were tested for significant differences (p < 0.05) every 2 minutes of a continuous 20-min run using a two-factor ANOVA (group × time) with one repeated measure (time). Coefficients of variation (CV) for each dependent measure were tested for statistical significance in the same way. There were no significant differences in F1, LR, or F2 over any samples for the 20-min running trials. There were no significant changes in CV values for the duration of the run. The results from the present study suggest that after 30 seconds of treadmill running, there were no significant within-day accommodation effects on vertical force measures over a 20-min treadmill run. Variability between individuals in the consistency of force measures, however, could be a confounding factor. This lack of consistent response for individuals should be considered when exposing participants to experimental designs involving treadmill locomotion.

Enhancing the Accuracy of Vertical Ground Reaction Force Measurement During Walking Using Pressure-Measuring Insoles

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Jessica DeBerardinis ◽  
Mohamed B. Trabia ◽  
Janet S. Dufek ◽  
Yann Le Gall ◽  
Nicolas Da Silva Sacoto
Keyword(s):  
System Identification ◽  
Ground Reaction Force ◽  
Transfer Functions ◽  
Force Measurement ◽  
Reaction Force ◽  
Vertical Component ◽  
Force Platform ◽  
Transfer Model ◽  
Vertical Ground Reaction Force ◽  
Identification Techniques

Abstract Pressure-measuring insoles can be an attractive tool for measuring ground reaction force (GRF) since they are portable and can record multiple consecutive steps. Several researchers have, however, observed that these insoles are less accurate than instrumented force platforms. To address this issue, the authors identified transfer functions that best described each insole size to enhance the measurements of the vertical component of GRF during walking. GRF data were collected from 29 participants (6/23 male/female, 24.3 ± 6.7 yrs, 70.4 ± 23.9 kg, 1.66 ± 0.11 m) using Medilogic® pressure-measuring insoles and Kistler® force platforms for three walking trials. Participants provided the institutionally approved written consent (IRB #724468). The data from both instruments were preprocessed. A subset of the data was used to train the system identification toolbox (matlab) to identify the coefficients of several candidate transfer functions for each insole size. The resulting transfer functions were compared using all available data for each insole to assess which one modified the insole data to be closer to that of the force platform. All tested transfer functions moved the vertical component of GRF closer to the corresponding force platform data. Each insole size had a specific transfer model that that yielded the best results. Using system identification techniques produced transfer functions that, when using insole data of the vertical component of GRF as input, produced output that is comparable to the corresponding measurement using an instrumented force platform.

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