Simulating the Effects of Anthropometry on the Contralateral Limb of Transtibial Amputees

Gait analysis is a clinically relevant method to assess walking patterns in rehabilitating patients, especially transtibial amputees. Prior work in biomechanics has detailed the impacts of below-the-knee amputation and anthropometric characteristics on patient gait, but little work has been done in the intersection of these fields, particularly with consideration towards the contralateral (intact) limb. This study utilizes OpenSim, a biomechanics simulation package, to investigate the impact of anthropometry on the stresses and response behavior of the hip, knee, and ankle joints in the contralateral limb of transtibial amputees. Musculoskeletal geometry, gait, and ground reaction force data for models were sourced from a healthy subject and appropriately adjusted based on amputation status and anthropometry. Inverse dynamics operations were performed on each model. Results indicate the need for special clinical focus on the ankle of heavier, taller amputees, along with the prescription of appropriate prosthetic componentry with a sufficient range of motion, to prevent long-term joint damage within the lower extremities. Initial data is preliminary, but serves as a foundation for additional simulations and related work in biomechanics simulations.

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Compromised Dynamic Postural Stability Under Increased Load Carriage Magnitudes

Journal of Applied Biomechanics ◽

10.1123/jab.2018-0473 ◽

2020 ◽

Vol 36 (1) ◽

pp. 27-32

Author(s):

Alice D. LaGoy ◽

Caleb Johnson ◽

Katelyn F. Allison ◽

Shawn D. Flanagan ◽

Mita T. Lovalekar ◽

...

Keyword(s):

Body Weight ◽

Postural Stability ◽

Reaction Force ◽

Stability Index ◽

Load Carriage ◽

Men And Women ◽

Similar Performance ◽

The Impact ◽

Dynamic Postural Stability ◽

Force Data

Warfighter performance may be compromised through the impact of load carriage on dynamic postural stability. Men and women may experience this impact to differing extents due to postural stability differences. Therefore, the authors investigated the effect of load magnitude on dynamic postural stability in men and women during a landing and stabilization task. Dynamic postural stability of 32 subjects (16 women) was assessed during the unilateral landing of submaximal jumps under 3 load conditions: +0%, +20%, and +30% body weight. Dynamic postural stability was measured using the dynamic postural stability index, which is calculated from ground reaction force data sampled at 1200 Hz. Two-way mixed-measures analysis of variance compared dynamic postural stability index scores between sexes and loads. Dynamic postural stability index scores were significantly affected by load (P = .001) but not by sex or by the sex by load interaction (P > .05). Dynamic postural stability index scores increased between the 0% (0.359 ± 0.041), 20% (0.396 ± 0.034), and 30% (0.420 ± 0.028) body weight conditions. Increased load negatively affects dynamic postural stability with similar performance decrements displayed by men and women. Men and women warfighters may experience similar performance decrements under load carriage conditions of similar relative magnitudes.

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The Effects of Cycling on Running Mechanics

Journal of Applied Biomechanics ◽

10.1123/jab.12.4.470 ◽

1996 ◽

Vol 12 (4) ◽

pp. 470-479 ◽

Cited By ~ 13

Author(s):

Edward J. Quigley ◽

James G. Richards

Keyword(s):

High Speed ◽

Reaction Force ◽

Vertical Displacement ◽

Ankle Joints ◽

Angular Velocities ◽

Reaction Forces ◽

Stance Time ◽

Left And Right ◽

Force Data ◽

Running Mechanics

This study investigated the mechanical effects that cycling has on running style which may explain the discomfort associated with the transition from cycling to running. The joint angles, angular velocities, reaction forces, and reaction moments of the left and right hip, knee, and ankle joints as well as stance time, flight time, stride length, and maximum vertical displacement of the center of gravity were measured using high-speed video and ground reaction force data. Data were collected from 11 competitive biathletes and triathletes. Each subject's running mechanics were determined from 10 trials for each of three conditions: (a) unfatigued, (b) immediately following 30 min of running, and (c) immediately following 30 min of bicycling. The results indicate that a person's running mechanics, as described by the variables above, are virtually unchanged between each of the three conditions. Therefore, awkwardness of the bicycle-to-run transition may not be related to a change in running mechanics.

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A Biomechanical Study of Side Steps at Different Distances

Journal of Applied Biomechanics ◽

10.1123/jab.29.3.336 ◽

2013 ◽

Vol 29 (3) ◽

pp. 336-345 ◽

Cited By ~ 19

Author(s):

Yuki Inaba ◽

Shinsuke Yoshioka ◽

Yoshiaki Iida ◽

Dean C. Hay ◽

Senshi Fukashiro

Keyword(s):

Inverse Dynamics ◽

Center Of Mass ◽

Reaction Force ◽

Biomechanical Study ◽

Joint Torque ◽

Large Power ◽

Lower Extremity Muscle ◽

Ankle Joints ◽

Hip Abduction ◽

Muscle Groups

Lateral quickness is a crucial component of many sports. However, biomechanical factors that contribute to quickness in lateral movements have not been understood well. Thus, the purpose of this study was to quantify 3-dimensional kinetics of hip, knee, and ankle joints in side steps to understand the function of lower extremity muscle groups. Side steps at nine different distances were performed by nine male subjects. Kinematic and ground reaction force data were recorded, and net joint torque and work were calculated by a standard inverse-dynamics method. Extension torques and work done at hip, knee, and ankle joints contributed substantially to the changes in side step distances. On the other hand, hip abduction work was not as sensitive to the changes in the side step distances. The main roles of hip abduction torque and work were to accelerate the center of mass laterally in the earlier phase of the movement and to keep the trunk upright, but not to generate large power for propulsion.

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The impact of injuries below the knee joint on the long-term functional outcome following polytrauma

Injury ◽

10.1016/j.injury.2004.06.004 ◽

2005 ◽

Vol 36 (1) ◽

pp. 169-177 ◽

Cited By ~ 53

Author(s):

B.A. Zelle ◽

S.R. Brown ◽

M. Panzica ◽

R. Lohse ◽

N.A. Sittaro ◽

...

Keyword(s):

Knee Joint ◽

Functional Outcome ◽

Below The Knee ◽

The Impact

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Experimental recommendations for estimating lower extremity loading based on joint and activity

10.1101/2021.05.14.444184 ◽

2021 ◽

Author(s):

Todd J Hullfish ◽

John F Drazan ◽

Josh R Baxter

Keyword(s):

Ground Reaction Force ◽

Lower Cost ◽

Inverse Dynamics ◽

Reaction Force ◽

Physical Measurements ◽

Musculoskeletal Models ◽

Shear Component ◽

Inverse Dynamics Problem ◽

Joint Loads ◽

The Impact

Researchers often estimate joint loading using musculoskeletal models to solve the inverse dynamics problem. This approach is powerful because it can be done non-invasively, however, it relies on assumptions and physical measurements that are prone to measurement error. The purpose of this study was to determine the impact of these errors - specifically, segment mass and shear ground reaction force - have on analyzing joint loads during activities of daily living. We preformed traditional marker-based motion capture analysis on 8 healthy adults while they completed a battery of exercises on 6 degree of freedom force plates. We then scaled the mass of each segment as well as the shear component of the ground reaction force in 5% increments between 0 and 200% and iteratively performed inverse dynamics calculations, resulting in 1,681 mass-shear combinations per activity. We compared the peak joint moments of the ankle, knee, and hip at each mass-shear combination to the 100% mass and 100% shear combination to determine the percent error. We found that the ankle was most resistant to changes in both mass and shear and the knee was resistant to changes in mass while the hip was sensitive to changes in both mass and shear. These results can help guide researchers who are pursuing lower-cost or more convenient data collection setups.

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Suppressed, but Not Forgotten

Swiss Journal of Psychology ◽

10.1024/1421-0185/a000033 ◽

2011 ◽

Vol 70 (1) ◽

pp. 5-11 ◽

Cited By ~ 8

Author(s):

Beat Meier ◽

Anja König ◽

Samuel Parak ◽

Katharina Henke

Keyword(s):

Memory Trace ◽

Thought Suppression ◽

Test Phase ◽

Indirect Test ◽

Final Test ◽

Test Experiment ◽

And Control ◽

Cue Words ◽

The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

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