scholarly journals Application of Wind Tunnel Device for Evaluation of Biokinetic Parameters of Running

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 505
Author(s):  
Brane Širok ◽  
Jurij Gostiša ◽  
Matej Sečnik ◽  
Krzysztof Mackala ◽  
Milan Čoh
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
High Tech ◽  
Ground Reaction Forces ◽  
Contact Phase ◽  
Kinetic Measurements ◽  
Foot Placement ◽  
Reaction Forces ◽  
Biokinetic Parameters ◽  
Tunnel System

The aim of the study was the application of high-tech wind tunnel device to identify the changes in the biokinetic parameters of running performed on the specially designed treadmill. The research was carried out in the “Planica Nordic Centre—PNC” in the wind tunnel system, where the AirRunner Assault treadmill, which was equipped with four sensors measuring the vertical and horizontal ground reaction forces, was installed. To obtain biokinetic data, the runners performed the treadmill’s run under conditions of airflow directed at each participant’s back (backwind speeds + 3 m/s and +5 m/s) and the chest (headwind speeds −5 m/s and −7 m/s). The runner’s speed was measured via image analysis using a DSLR camera and markers on the belt of the treadmill. Additionally, a high-speed camera synchronised to the force acquisition system was used to analyse the contact phase via comparison of foot placement and time series of the ground reaction forces. The contact phases of the running step were found to be longer than the flight phases, with their duration ranging from 0.15 to 0.20 s and the maximum forces at take-off were found to be greater than when running with the backwind. It should be noted that the application of high-tech devices wind tunnel and treadmill were found to be sufficiently accurate to perform kinetic measurements of running parameters in changing conditions, such as resistance and assistance (facilitating).

Twisting and Bending: The Functional Role of Salamander Lateral Hypaxial Musculature During Locomotion

2001 ◽  
Vol 204 (11) ◽  
pp. 1979-1989 ◽  
Author(s):  
Wallace O. Bennett ◽  
Rachel S. Simons ◽  
Elizabeth L. Brainerd
Keyword(s):  
High Intensity ◽  
High Speed ◽  
The Body ◽  
Transversus Abdominis ◽  
Fine Motor ◽  
Emg Activity ◽  
Ground Reaction Forces ◽  
Terrestrial Locomotion ◽  
Reaction Forces ◽  
Hypaxial Muscle

SUMMARY The function of the lateral hypaxial muscles during locomotion in tetrapods is controversial. Currently, there are two hypotheses of lateral hypaxial muscle function. The first, supported by electromyographic (EMG) data from a lizard (Iguana iguana) and a salamander (Dicamptodon ensatus), suggests that hypaxial muscles function to bend the body during swimming and to resist long-axis torsion during walking. The second, supported by EMG data from lizards during relatively high-speed locomotion, suggests that these muscles function primarily to bend the body during locomotion, not to resist torsional forces. To determine whether the results from D. ensatus hold for another salamander, we recorded lateral hypaxial muscle EMGs synchronized with body and limb kinematics in the tiger salamander Ambystoma tigrinum. In agreement with results from aquatic locomotion in D. ensatus, all four layers of lateral hypaxial musculature were found to show synchronous EMG activity during swimming in A. tigrinum. Our findings for terrestrial locomotion also agree with previous results from D. ensatus and support the torsion resistance hypothesis for terrestrial locomotion. We observed asynchronous EMG bursts of relatively high intensity in the lateral and medial pairs of hypaxial muscles during walking in tiger salamanders (we call these ‘α-bursts’). We infer from this pattern that the more lateral two layers of oblique hypaxial musculature, Mm. obliquus externus superficialis (OES) and obliquus externus profundus (OEP), are active on the side towards which the trunk is bending, while the more medial two layers, Mm. obliquus internus (OI) and transversus abdominis (TA), are active on the opposite side. This result is consistent with the hypothesis proposed for D. ensatus that the OES and OEP generate torsional moments to counteract ground reaction forces generated by forelimb support, while the OI and TA generate torsional moments to counteract ground reaction forces from hindlimb support. However, unlike the EMG pattern reported for D. ensatus, a second, lower-intensity burst of EMG activity (‘β-burst’) was sometimes recorded from the lateral hypaxial muscles in A. tigrinum. As seen in other muscle systems, these β-bursts of hypaxial muscle coactivation may function to provide fine motor control during locomotion. The presence of asynchronous, relatively high-intensity α-bursts indicates that the lateral hypaxial muscles generate torsional moments during terrestrial locomotion, but it is possible that the balance of forces from both α- and β-bursts may allow the lateral hypaxial muscles to contribute to lateral bending of the body as well.

Obesity: Effects on Gait in an Osteoarthritic Population

1996 ◽  
Vol 12 (2) ◽  
pp. 161-172 ◽  
Author(s):  
Stephen P. Messier ◽  
Walter H. Ettinger ◽  
Thomas E. Doyle ◽  
Timothy Morgan ◽  
Margaret K. James ◽  
...  
Keyword(s):  
Older Adults ◽  
High Speed ◽  
Ground Reaction Forces ◽  
Vertical Force ◽  
Kinematic Data ◽  
Knee Oa ◽  
Significant Relationships ◽  
Gait Mechanics ◽  
Reaction Forces ◽  
Walking Velocity

The purpose of our study was to examine the association between obesity and gait mechanics in older adults with knee osteoarthritis (OA). Subjects were 101 older adults (25 males and 76 females) with knee OA. High-speed video analysis and a force platform were used to record sagittal view lower extremity kinematic data and ground reaction forces. Increased body mass index (BMI) was significantly related to both decreases in walking velocity and knee maximum extension. There were no significant relationships between BMI and any of the hip or ankle kinematic variables. BMI was directly related to vertical force minimum and maximum values, vertical impulse, and loading rate. Increases in braking and propulsive forces were significantly correlated with increased BMI. Maximum medially and laterally directed ground reaction forces were positively correlated with BMI. Our results suggests that, in subjects with knee OA, obesity is associated with an alteration in gait.

scholarly journals Contribution of Cutaneous Inputs From the Hindpaw to the Control of Locomotion. I. Intact Cats

2003 ◽  
Vol 90 (6) ◽  
pp. 3625-3639 ◽  
Author(s):  
L.J.G. Bouyer ◽  
S. Rossignol
Keyword(s):  
Control Level ◽  
Companion Paper ◽  
Treadmill Walking ◽  
Emg Activity ◽  
Ground Reaction Forces ◽  
Phase Duration ◽  
Foot Placement ◽  
Cutaneous Feedback ◽  
Adaptive Mechanisms ◽  
Reaction Forces

The goal of this study was to evaluate the role of hindpaw cutaneous feedback in the control of locomotion, by cutting some (in one cat) or all (in 2 cats) cutaneous nerves bilaterally at ankle level. Kinematic and electromyographic (EMG) recordings were obtained before and for several weeks after denervation during level and incline (15° up and down) treadmill walking. Ladder walking and ground reaction forces were also documented sporadically. Early after the denervation (1–3 days), cats could not walk across a ladder, although deficits were small during level treadmill walking. Increased knee flexion velocity caused a 14% reduction in swing phase duration. EMG activity was consistently increased in knee, ankle, and toe flexors, and in at least one knee or ankle extensor. The adaptive changes during walking on the incline were much reduced after denervation. Ladder walking gradually recovered within 3–7 wk. By this time, level treadmill walking kinematics had completely returned to normal, but EMG activity in flexors remained above control. Incline walking improved but did not return to normal. Mediolateral ground reaction forces during overground walking were increased by 200%. It is concluded that in intact cats, cutaneous inputs contribute more to demanding situations such as walking on a ladder or on inclines than to level walking. Active adaptive mechanisms are likely involved given that the EMG locomotor pattern never returned to control level. The companion paper shows on the other hand that when the same cats are spinalized, these cutaneous inputs become critical for foot placement during locomotion.

scholarly journals Race Walking Ground Reaction Forces at Increasing Speeds: A Comparison with Walking and Running

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 873
Author(s):  
Gaspare Pavei ◽  
Dario Cazzola ◽  
Antonio La Torre ◽  
Alberto E. Minetti
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
The Body ◽  
Ground Reaction Forces ◽  
Centre Of Mass ◽  
Walking Gait ◽  
Wide Range ◽  
Reaction Forces ◽  
Race Walking ◽  
Walking Speeds

Race walking has been theoretically described as a walking gait in which no flight time is allowed and high travelling speed, comparable to running (3.6–4.2 m s−1), is achieved. The aim of this study was to mechanically understand such a “hybrid gait” by analysing the ground reaction forces (GRFs) generated in a wide range of race walking speeds, while comparing them to running and walking. Fifteen athletes race-walked on an instrumented walkway (4 m) and three-dimensional GRFs were recorded at 1000 Hz. Subjects were asked to performed three self-selected speeds corresponding to a low, medium and high speed. Peak forces increased with speeds and medio-lateral and braking peaks were higher than in walking and running, whereas the vertical peaks were higher than walking but lower than running. Vertical GRF traces showed two characteristic patterns: one resembling the “M-shape” of walking and the second characterised by a first peak and a subsequent plateau. These different patterns were not related to the athletes’ performance level. The analysis of the body centre of mass trajectory, which reaches its vertical minimum at mid-stance, showed that race walking should be considered a bouncing gait regardless of the presence or absence of a flight phase.

EFFECTIVENESS OF FLOOR MARKINGS FOR CONTROLLING CUT WIDTH DURING SIDE CUTTING TASKS IN LABORATORY EXPERIMENTS

2020 ◽  
Vol 20 (01) ◽  
pp. 1950076
Author(s):  
JING WEN PAN ◽  
THORSTEN STERZING ◽  
JUN WEI PANG ◽  
YAOHUI KELVIN CHUA ◽  
PUI WAH KONG
Keyword(s):  
Lower Extremity ◽  
Hip Joint ◽  
Laboratory Experiments ◽  
Ground Reaction Forces ◽  
Basketball Players ◽  
Foot Placement ◽  
Body Postures ◽  
Motion Data ◽  
Reaction Forces ◽  
The Difference

This study examined the effectiveness of floor markings for controlling cut width during the analysis of side cutting maneuvers. Eleven male basketball players performed two side cutting maneuvers of narrow (30[Formula: see text]cm) and wide (45[Formula: see text]cm) cut widths and were guided by floor markings. Ground reaction forces, together with ankle, knee, and hip joint ranges of motion (ROM), and respective joint moments were determined. Cut widths were verified by two approaches by calculating the actual foot-to-foot and foot-to-pelvis distances from motion data. Biomechanical lower extremity loading showed no significant differences in most kinetic and kinematic variables between narrow and wide cuts. The difference in foot-to-foot distance (15.1 [11.6, 18.7] cm, [Formula: see text] between conditions corresponded well with floor markings, however, the difference in foot-to-pelvis distance was much smaller (2.3 [0.3, 4.4] cm, [Formula: see text]. It is concluded that floor markings are not sufficient for controlling the actual anatomical cut width in laboratory experiments. Participants may adjust their body postures to maintain similar lower extremity loading when performing side cuts differing in foot placement width. Cut width should be represented by foot-to-pelvis distance and not foot-to-foot distance.

scholarly journals Design, Construction and Testing of a Desktop Supersonic Wind Tunnel

2005 ◽  
Vol 4 (2) ◽  
Author(s):  
Vi Rapp ◽  
Jennifer Jacobsen ◽  
Mark Lawson ◽  
Andrew Parker ◽  
Kuan Chen
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Compressible Flows ◽  
Supersonic Flows ◽  
Load Cell ◽  
Test Facility ◽  
Supersonic Wind Tunnel ◽  
Tunnel System ◽  
Design Construction ◽  
Good Agreement

A mobile and affordable, miniature wind tunnel to aid students in studying high-speed compressible flows was constructed and tested. Millimeter-sized nozzles of different contours were fabricated to produce supersonic flows at Mach 2. The complete system consists of a converging-diverging nozzle, a load cell, pressure and temperature sensors, a tank to store high-pressure gases, and a computer-aided data acquisition system. The wind tunnel system is mounted to a cart, making it convenient to move. This test facility allows students to study and test supersonic flows in a safer environment while eliminating the high costs for a full-sized facility. Gas pressure was measured at various locations in the nozzle. A load cell consisting of four cantilever beams was constructed and used to determine the thrust of the nozzle. Data collected from each nozzle was compared to numerical simulations. In all cases, the simulations were in good agreement with the experimental data.

scholarly journals The compliant effect of controlled spine on interaction with the ground in quadruped trotting

2019 ◽  
Vol 234 (1) ◽  
pp. 27-45 ◽  
Author(s):  
Zhang Li ◽  
Yuegang Tan ◽  
Ping Wu ◽  
Shun Zeng
Keyword(s):  
High Speed ◽  
Lumbar Vertebra ◽  
Quadruped Robot ◽  
Ground Reaction Forces ◽  
Gait Simulation ◽  
Compliant Control ◽  
Reaction Forces ◽  
Motion Performance ◽  
The Stability ◽  
Flat Ground

The spine plays important roles in the quadruped locomotion. These effects not only stand out in high-speed gait but also function in low-speed gait, especially the transition gait – trotting gait. In order to investigate the effects of the spine on the motion performance of the quadruped trotting, the spine with two joints is applied into the structure of the quadruped robot. This structure is inspired from the analyses for the canine, which imitates the configuration of thoracic vertebra, front lumbar vertebra and hind lumbar vertebra. Different from the quadruped robot with the passive spine or the active spine by inputting position, a compliant control is applied to the spinal joints. The feature of force control not only possesses the soft feature of the passive spine but also has the advantage of enlarging the motion ability. In the simulation process, a large amount of analyses are carried out including the influence of the control parameters of the controlled spine, the comparison with the quadruped robot with rigid torso and the gait simulation when the robot moves on the flat ground and across an obstacle. The results reveal that the controlled spine has an excellent compliant effect on the interaction with the ground. It contributes to reducing the ground reaction forces; meanwhile, the compliant effect is beneficial for improving the stability. By establishing the prototype robot and performing the motion experiment, the compliant effect of the spine is proven effective.

Sign in / Sign up

Export Citation Format

Share Document