EFFECTS OF WRIST GUARD AND ELBOW ARREST STRATEGY ON IMPACT FORCE IN FORWARD FALLS

2021 ◽  
pp. 2150046
Author(s):  
Yan-Ren Lin ◽  
Chiung-Ling Chen ◽  
Yu-Chi Chen ◽  
Min-Hsien Cho ◽  
Shu-Zon Lou
Keyword(s):  
Loading Rate ◽  
Impact Force ◽  
Reaction Force ◽  
Previous History ◽  
Force Plate ◽  
Wrist Guard ◽  
The Impact ◽  
Forward Falls ◽  
Fall Height ◽  
Peak Impact Force

Wrist guards are widely used for preventing distal radius fracture during in-line skating and snowboard-related activities. However, more than half of people wearing wrist guards nonetheless sustain a fracture of the wrist in forward falls. Accordingly, this study evaluates the effects of three factors, namely the wrist guard design, the fall height and the arrest strategy, on the impact force during a forward fall onto a single outstretched hand. Fifteen physically healthy male participants volunteered for the biomechanical investigation. None of the participants had a previous history of upper extremity injuries or disorders. A 1000[Formula: see text]Hz AMTI force plate was used to measure the ground reaction force (GRF) in forward falls performed using a self-built release system onto a single hand. The GRF and impact time were analyzed in terms of three factors, namely (1) the wrist guard design, including bare hand (BH), conventional wrist guard (WG), wrist guard pad on palm (WG+), and WG+ with no lower splint (WG[Formula: see text]; (2) the elbow arrest strategy, including elbow extended and elbow flexed; and (3) the fall height, including 4[Formula: see text]cm and 8[Formula: see text]cm. The impact force and loading rate significantly increased with an increasing fall height. However, the elbow flexed strategy attenuated the GRF peak force and delayed the point of peak impact force. The GRF in the WG, WG+ and WG− conditions was significantly lower than that in the BH condition. Overall, a lower fall height, a wrist guard with a compliant pad (WG+ or WG[Formula: see text], and an elbow flexed strategy reduced the impact force, delayed the peak impact force, and reduced the loading rate in forward falls.

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.

Effect of Running Speed and Aerobic Dance Jump Height on Vertical Ground Reaction Forces

1994 ◽  
Vol 10 (1) ◽  
pp. 14-27 ◽  
Author(s):  
Mark D. Ricard ◽  
Steve Veatch
Keyword(s):  
High Frequency ◽  
Loading Rate ◽  
Impact Force ◽  
Reaction Force ◽  
Running Speed ◽  
Dance Movement ◽  
Aerobic Dance ◽  
Impact Forces ◽  
Peak Impact Force ◽  
Frequency Impulse

Aerobic dance movement sequences are similar to running in repetitive frequency. The purpose of this study was to compare ground reaction force variables in aerobic dance and running. Five female subjects performed 10 trials of five running speeds (2.4–4.0 ± 0.4 m/s) and five heights (0–8 ± 0.2 cm) of front knee lift aerobic dance steps on an AMTI force plate (1000 Hz). First peak impact force, peak loading rate, high-frequency impulse, and 50-ms impulse increased with increased running speed and jumping height. Time to first peak impact force decreased as running speed and jumping height increased. Although first peak impact forces resulting from airborne aerobic dance movements (1.96–2.62 BW) were greater than first peak impact forces in running (1.30–2.01 BW), running compared to aerobic dance resulted in shorter time to first peak impact force and higher values for loading rate, high-frequency impulse, and 50-ms impulse. When compared to aerobic dance, running exhibits smaller peak vertical forces but higher loading rates and vertical impulses.

scholarly journals Effects of Two Fatigue Protocols on Impact Forces and Lower Extremity Kinematics during Drop Landings: Implications for Noncontact Anterior Cruciate Ligament Injury

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Rui Xia ◽  
Xini Zhang ◽  
Xi Wang ◽  
Xiaole Sun ◽  
Weijie Fu
Keyword(s):  
Loading Rate ◽  
Impact Force ◽  
Collegiate Athletes ◽  
Maximal Heart Rate ◽  
Fatigue Protocol ◽  
Impact Forces ◽  
Duration Time ◽  
Drop Landing ◽  
The Impact ◽  
Peak Impact Force

The purpose of the study was to determine the effects of fatigue on the impact forces and sagittal plane kinematics of the lower extremities in a drop landing task. 15 male collegiate athletes were recruited. Five successful trials of a drop landing task were obtained during prefatigue and postfatigue in two fatigue protocols (constant speed running fatigue protocol [R-FP] and shuttle running + vertical jumping fatigue protocol [SV-FP]). Duration time, maximal heart rate, and RPE of each protocol were measured separately. Kinematic measures of the hip, knee, and ankle joints at different times coupled with peak impact force and loading rate were acquired. Our results showed a more flexed landing posture due to an increase in hip and knee flexion angles in the postfatigue condition. However, no differences in peak impact force and loading rate were found between pre- and postfatigue conditions. The changes were similar between protocols, but the SV-FP showed a significantly shorter exercise duration time than the R-FP. Fatigued athletes in this study demonstrated altered motor control strategies during a drop landing task, which may be an intentional or unintentional protective strategy for preventing themselves from potential ACL injury.

Influence of heel design in an orthopedic shoe on ground reaction forces during walking

2016 ◽  
Vol 40 (5) ◽  
pp. 598-605 ◽  
Author(s):  
Aliyeh Daryabor ◽  
Hassan Saeedi ◽  
Mohammad Sadegh Ghasemi ◽  
Meria Yazdani ◽  
Mohammad Kamali ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Impact Force ◽  
Reaction Force ◽  
Force Plate ◽  
Impact Loads ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Quasi Experimental ◽  
Reaction Forces ◽  
The Impact

Background: One of the treatments prescribed for musculoskeletal patients is orthopedic shoe. The use of an orthopedic shoe is thought to produce a more typical ground reactive force pattern. Objectives: This study was designed to determine the influence of three heel designs of an orthopedic shoe on the ground reaction forces during walking in healthy subjects. Study design: Quasi-experimental. Method: In total, 30 healthy adults (12 males, 18 females) walked at a self-selected pace for six trials in each of the three shoe conditions having three different heels which included the following: standard heel, beveled heel, and positive posterior heel flare. For each trial, ground reaction force parameters were recorded using a force plate. Results: Repeated measures analysis of variance indicated that the impact force was significantly reduced for the positive posterior heel flare condition by 8% and 13% compared with standard and beveled heels, respectively ( p < 0.001). The first peak of vertical force showed a significant reduction in the beveled heel by 5% and 4% compared with the standard heel and the positive posterior heel flare, respectively ( p < 0.001). Loading rate was significantly reduced in the beveled heel and the positive posterior heel flare conditions ( p < 0.05). Conclusion: Positive posterior heel flare reduced impact force due to its geometry flexibility, while a beveled heel reduced first peak of vertical force. The findings of this study show that the shape of the heel therefore has the potential to modify impact loads during walking. Clinical relevance This study provides new evidence that by changing shape in the heel of orthopedic shoe impact loads are reduced during walking. Thus, these findings indicate that use of heel design may be beneficial for various musculoskeletal disorders, including key public health problems.

Dynamic Response and Shear Demand of Reinforced Concrete Beams Subjected to Impact Loading

2019 ◽  
Vol 19 (08) ◽  
pp. 1950091 ◽  
Author(s):  
Wuchao Zhao ◽  
Jiang Qian
Keyword(s):  
Dynamic Response ◽  
Impact Loading ◽  
Parametric Study ◽  
Shear Failure ◽  
Impact Force ◽  
Rc Beams ◽  
Local Response ◽  
Shear Demand ◽  
The Impact ◽  
Peak Impact Force

Reinforced concrete (RC) beams under the impact loading are typically prone to suffer shear failure in the local response phase. In order to enhance the understanding of the mechanical behavior of the RC beams, their dynamic response and shear demand are numerically investigated in this paper. A 3D finite-element model is developed and validated against the experimental data available in the literature. Taking advantage of the above calibrated numerical model, an intensive parametric study is performed to identify the effect of different factors including the impact velocity, impact mass and beam span-to-depth ratio on the impact response of the RC beams. It is found that, due to the inertial effect, a linear relationship exists between the maximum reverse support force and the peak impact force, while negative bending moments also appear in the shear span. In addition, the local response of the RC beams can be divided into a first impact stage and a separation stage. A shear plug is likely to be formed near the impact point at the first impact stage and a shear failure may be triggered near the support by large support forces. Based on the simulation results, simplified methods are proposed for predicting the shear demand for the two failure modes, whereas physical models are also established to illustrate the resistance mechanism of the RC beams at the peak impact force. By comparing with the results of the parametric study, it is concluded that the shear demand of the RC beams under the impact loading can be predicted by the proposed empirical formulas with reasonable accuracy.

scholarly journals Landing Control of Foot with Springs for Walking Robots on Rough Terrain

10.5772/7238 ◽  
2009 ◽  
Vol 6 (3) ◽  
pp. 25 ◽  
Author(s):  
Moyuru Yamada ◽  
Shigenori Sano ◽  
Naoki Uchiyama
Keyword(s):  
Controller Design ◽  
Impact Force ◽  
Reaction Force ◽  
Walking Robots ◽  
Flat Surfaces ◽  
Uneven Terrain ◽  
Biped Walking Robot ◽  
Foot Position ◽  
The Impact ◽  
Landing Control

Landing control is one of the important issues for biped walking robot, because robots are expected to walk on not only known flat surfaces but also unknown and uneven terrain for working at various fields. This paper presents a new controller design for a robotic foot to land on unknown terrain. The robotic foot considered in this study equips springs to reduce the impact force at the foot landing. There are two objectives in the landing control; achieving the desired ground reaction force and positioning the foot on unknown terrain. To achieve these two objectives simultaneously by adjusting the foot position, we propose a PI force controller with a desired foot position, which guarantees the robust stability of control system with respect to terrain variance, and exact positioning of the foot to unknown terrain. Simulation results using the Open Dynamics Engine demonstrate the effectiveness of the proposed controller.

scholarly journals Effect of Abrasive Concentration on Impact Performance of Abrasive Water Jet Crushing Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Xiaohui Liu ◽  
Ping Tang ◽  
Qi Geng ◽  
Xuebin Wang
Keyword(s):  
Internal Energy ◽  
Impact Force ◽  
Abrasive Particle ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Sph Method ◽  
Impact Performance ◽  
Water Jets ◽  
The Impact ◽  
Peak Impact Force

It has been found that the impact performance of water jets can be changed by its properties, which include pressure, additive, and mode of jet. Thus, an abrasive water jet (AWJ) has been developed as a new method. However, there is little research on the effect of abrasive concentration on the impact performance of abrasive jets. Thus, the SPH method is used to establish an abrasive water jet crushing concrete model to study the effect of abrasive concentration on the impact force, concrete internal energy, abrasive particle distribution, crushing depth, and damage and crushing efficiencies under different concrete compressive strengths and abrasive densities. The results indicate that there is little effect of the abrasive concentration on the peak impact force under different compressive strengths and abrasive densities, while the mean impact force tends to increase linearly with the abrasive concentration. The internal energy of the concrete increases stepwise with the abrasive concentration under different compressive strengths and abrasive densities. The concentration of 10%∼20% is the rapid increasing stage. The crushing depth and damage efficiencies are all maximum at a concentration of 20% under different compressive strengths and abrasive densities. After the concrete was impacted by the water from the water jet, it is divided into rebounding particles and intrusive particles. The more the intrusive particles, the easier the concrete to be crushed and damaged.

The Efficacy of Impact-Absorbing Materials during Collision with a Soccer Ball

2013 ◽  
Vol 440 ◽  
pp. 363-368
Author(s):  
Zahari Taha ◽  
Mohd Hasnun Arif Hassan ◽  
Mohd Azri Aris
Keyword(s):  
High Speed ◽  
Impact Force ◽  
Coefficient Of Restitution ◽  
Soccer Ball ◽  
Absorbing Materials ◽  
The Subject ◽  
The Impact ◽  
The Brain ◽  
Peak Impact Force ◽  
Impact Duration

The uniqueness of soccer is that the players are allowed to use their head to pass the ball to a teammate of even try to score goal. Studies have shown that heading in soccer might be dangerous to the brain and could lead to brain trauma. There are headgears available for soccer players to protect their head, but studies have proven that currently available headgears are ineffective in reducing the impact caused by a soccer ball. The objective of this study is to test the efficacy of six different types of impact-absorbing materials in reducing the linear impact force from a soccer ball. The soccer ball was dropped from the height of 2.3 m onto a force platform to measure the impact force. A high-speed camera is used to record the motion and the impact duration, and then the coefficient of restitution for each impact was determined. Polyurethane (PU) comb-gel was found to be the most effective material in reducing the peak impact force and impulse compared with other materials. The reduction in peak force was associated with longer impact duration between the soccer ball and the PU comb-gel. However, the coefficient of restitution was reduced by 21.7%, implying that using the gel alone will reduce the speed of the ball after heading, thus reducing the performance of a player wearing it. A combination of PU gel and another stiffer material is suggested and the effectiveness of the composite will be the subject of future investigation.

scholarly journals Do Strike Patterns or Shoe Conditions Have a Predominant Influence on Foot Loading?

2018 ◽  
Vol 64 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Xiaole Sun ◽  
Yang Yang ◽  
Lin Wang ◽  
Xini Zhang ◽  
Weijie Fu
Keyword(s):  
Plantar Pressure ◽  
Loading Rate ◽  
Peak Pressure ◽  
Impact Force ◽  
Pressure System ◽  
Risk Of Injury ◽  
Maximum Loading ◽  
Peak Plantar Pressure ◽  
Foot Loading ◽  
The Impact

Abstract This study aimed to explore the effects of strike patterns and shoe conditions on foot loading during running. Twelve male runners were required to run under shoe (SR) and barefoot conditions (BR) with forefoot (FFS) and rearfoot strike patterns (RFS). Kistler force plates and the Medilogic insole plantar pressure system were used to collect kinetic data. SR with RFS significantly reduced the maximum loading rate, whereas SR with FFS significantly increased the maximum push-off force compared to BR. Plantar pressure variables were more influenced by the strike patterns (15 out of 18 variables) than shoe conditions (7 out of 18 variables). The peak pressure of midfoot and heel regions was significantly increased in RFS, but appeared in a later time compared to FFS. The influence of strike patterns on running, particularly on plantar pressure characteristics, was more significant than that of shoe conditions. Heel-toe running caused a significant impact force on the heel, whereas wearing cushioned shoes significantly reduced the maximum loading rate. FFS running can prevent the impact caused by RFS. However, peak plantar pressure was centered at the forefoot for a long period, thereby inducing a potential risk of injury in the metatarsus/phalanx.

scholarly journals Accelerometer-based prediction of ground reaction force in head-out water exercise with different exercise intensity countermovement jump

2022 ◽  
Vol 14 (1) ◽  
Author(s):  
Kuei-Yu Chien ◽  
Wei-Gang Chang ◽  
Wan-Chin Chen ◽  
Rong-Jun Liou
Keyword(s):  
Ground Reaction Force ◽  
Reaction Force ◽  
Body Height ◽  
Force Plate ◽  
Prediction Equation ◽  
Regression Equations ◽  
Countermovement Jump ◽  
Predictive Regression ◽  
Seventh Cervical Vertebra ◽  
The Impact

Abstract Background Water jumping exercise is an alternative method to achieve maintenance of bone health and reduce exercise injuries. Clarifying the ground reaction force (GRF) of moderate and high cardiopulmonary exercise intensities for jumping movements can help quantify the impact force during different exercise intensities. Accelerometers have been explored for measuring skeletal mechanical loading by estimating the GRFs. Predictive regression equations for GRF using ACC on land have already been developed and performed outside laboratory settings, whereas a predictive regression equation for GRF in water exercises is not yet established. The purpose of this study was to determine the best accelerometer wear-position for three exercise intensities and develop and validate the ground reaction force (GRF) prediction equation. Methods Twelve healthy women (23.6 ± 1.83 years, 158.2 ± 5.33 cm, 53.1 ± 7.50 kg) were recruited as participants. Triaxial accelerometers were affixed 3 cm above the medial malleolus of the tibia, fifth lumbar vertebra, and seventh cervical vertebra (C7). The countermovement jump (CMJ) cadence started at 80 beats/min and increased by 5 beats per 20 s to reach 50%, 65%, and 80% heart rate reserves, and then participants jumped five more times. One-way repeated analysis of variance was used to determine acceleration differences among wear-positions and exercise intensities. Pearson’s correlation was used to determine the correlation between the acceleration and GRF per body weight on land (GRFVLBW). Backward regression analysis was used to generate GRFVLBW prediction equations from full models with C7 acceleration (C7 ACC), age, percentage of water deep divided by body height (PWDH), and bodyweight as predictors. Paired t-test was used to determine GRFVLBW differences between values from the prediction equation and force plate measurement during validation. Lin’s CCC and Bland–Altman plots were used to determine the agreement between the predicted and force plate-measured GRFVLBW. Results The raw full profile data for the resultant acceleration showed that the acceleration curve of C7 was similar to that of GRFv. The predicted formula was − 1.712 + 0.658 * C7ACC + 0.016 * PWDH + 0.008 * age + 0.003*weight. Lin’s CCC score was 0.7453, with bias of 0.369%. Conclusion The resultant acceleration measured at C7 was identified as the valid estimated GRFVLBW during CMJ in water.

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