Estimating 3D L5/S1 moments and ground reaction forces during trunk bending using a full-body ambulatory inertial motion capture system

In the past, technological issues limited research focused on ski jump landing. Today, thanks to the development of wearable sensors, it is possible to analyze the biomechanics of athletes without interfering with their movements. The aims of this study were twofold. Firstly, the quantification of the kinetic magnitude during landing is performed using wireless force insoles while 22 athletes jumped during summer training on the hill. In the second part, the insoles were combined with inertial motion units (IMUs) to determine the possible correlation between kinematics and kinetics during landing. The maximal normal ground reaction force (GRFmax) ranged between 1.1 and 5.3 body weight per foot independently when landing using the telemark or parallel leg technique. The GRFmax and impulse were correlated with flying time (p < 0.001). The hip flexions/extensions and the knee and hip rotations of the telemark front leg correlated with GRFmax (r = 0.689, p = 0.040; r = −0.670, p = 0.048; r = 0.820, p = 0.007; respectively). The force insoles and their combination with IMUs resulted in promising setups to analyze landing biomechanics and to provide in-field feedback to the athletes, being quick to place and light, without limiting movement.

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Performance evaluation of a wearable inertial motion capture system for capturing physical exposures during manual material handling tasks

Ergonomics ◽

10.1080/00140139.2012.742932 ◽

2013 ◽

Vol 56 (2) ◽

pp. 314-326 ◽

Cited By ~ 74

Author(s):

Sunwook Kim ◽

Maury A. Nussbaum

Keyword(s):

Performance Evaluation ◽

Motion Capture ◽

Material Handling ◽

Motion Capture System ◽

Inertial Motion ◽

Manual Material Handling ◽

Physical Exposures

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Footwear and Elevated Heel Influence On Barbell Back Squat: a Review

Journal of Biomechanical Engineering ◽

10.1115/1.4050820 ◽

2021 ◽

Author(s):

Aaron Michael Pangan ◽

Matthew J Leineweber

Keyword(s):

Ground Reaction Forces ◽

Specific Effects ◽

Back Squat ◽

Running Shoes ◽

Different Types ◽

Reaction Forces ◽

Joint Loads ◽

The Impact ◽

Kinematics And Kinetics ◽

Full Body

Abstract The back squat is one of the most effective exercises in strengthening the muscles of the lower extremity. Understanding the impact of footwear has on the biomechanics is imperative for maximizing the exercise training potential, preventing injury, and rehabilitating from injury. This review focuses on how different types of footwear affect the full-body kinematics, joint loads, muscle activity, and ground reaction forces in athletes of varying experience performing the weighted back squat. The literature search was conducted using three databases, and fourteen full-text articles were ultimately included in the review. The majority of these studies demonstrated that the choice of footwear directly impacts kinematics and kinetics. Weightlifting shoes were shown to decrease trunk lean and generate more plantarflexion relative to running shoes and barefoot lifting. Elevating the heel through the use of external squat wedges is popular clinical exercise during rehabilitation and was shown to provide similar effects to WLS. Additional research with a broader array of populations, particularly novice and female weightlifters, should be conducted to generalize the research results to non-athlete populations. Further work is also needed to characterize the specific effects of sole stiffness and heel elevation height on squatting mechanics.

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Predicting ground reaction and tibiotalar contact forces after total ankle arthroplasty during walking

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411920947208 ◽

2020 ◽

Vol 234 (12) ◽

pp. 1432-1444

Author(s):

Yanwei Zhang ◽

Zhenxian Chen ◽

Yinghu Peng ◽

Hongmou Zhao ◽

Xiaojun Liang ◽

...

Keyword(s):

Motion Capture ◽

Multibody Dynamics ◽

Contact Forces ◽

Total Ankle Arthroplasty ◽

Contact Model ◽

Patient Specific ◽

Ground Reaction Forces ◽

Ground Contact ◽

Ankle Arthroplasty ◽

Reaction Forces

The motion capture and force plates data are essential inputs for musculoskeletal multibody dynamics models to predict in vivo tibiotalar contact forces. However, it could be almost impossible to obtain valid force plates data in old patients undergoing total ankle arthroplasty under some circumstances, such as smaller gait strides and inconsistent walking speeds during gait analysis. To remove the dependence of force plates, this study has established a patient-specific musculoskeletal multibody dynamics model with total ankle arthroplasty by combining a foot-ground contact model based on elastic contact elements. And the established model could predict ground reaction forces, ground reaction moments and tibiotalar contact forces simultaneously. Three patients’ motion capture and force plates data during their normal walking were used to establish the patient-specific musculoskeletal models and evaluate the predicted ground reaction forces and ground reaction moments. Reasonable accuracies were achieved for the predicted and measured ground reaction forces and ground reaction moments. The predicted tibiotalar contact forces for all patients using the foot-ground contact model had good consistency with those using force plates data. These findings suggested that the foot-ground contact model could take the place of the force plates data for predicting the tibiotalar contact forces in other total ankle arthroplasty patients, thus providing a simplified and valid platform for further study of the patient-specific prosthetic designs and clinical problems of total ankle arthroplasty in the absence of force plates data.

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Application of Inertial Motion Unit-Based Kinematics to Assess the Effect of Boot Modifications on Ski Jump Landings—A Methodological Study

Sensors ◽

10.3390/s20133805 ◽

2020 ◽

Vol 20 (13) ◽

pp. 3805

Author(s):

Nicolas Kurpiers ◽

Nicola Petrone ◽

Matej Supej ◽

Anna Wisser ◽

Jakob Hansen ◽

...

Keyword(s):

Motion Capture ◽

Methodological Approach ◽

Inertial Motion ◽

Winter Sports ◽

Training Time ◽

Video Recordings ◽

Extended Training ◽

Motion Unit ◽

Full Body ◽

Jump Landings

Biomechanical studies of winter sports are challenging due to environmental conditions which cannot be mimicked in a laboratory. In this study, a methodological approach was developed merging 2D video recordings with sensor-based motion capture to investigate ski jump landings. A reference measurement was carried out in a laboratory, and subsequently, the method was exemplified in a field study by assessing the effect of a ski boot modification on landing kinematics. Landings of four expert skiers were filmed under field conditions in the jump plane, and full body kinematics were measured with an inertial motion unit (IMU) -based motion capture suit. This exemplary study revealed that the combination of video and IMU data is viable. However, only one skier was able to make use of the added boot flexibility, likely due to an extended training time with the modified boot. In this case, maximum knee flexion changed by 36° and maximum ankle flexion by 13°, whereas the other three skiers changed only marginally. The results confirm that 2D video merged with IMU data are suitable for jump analyses in winter sports, and that the modified boot will allow for alterations in landing technique provided that enough time for training is given.

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