Using Musculoskeletal Modeling for Estimating the Most Important Muscular Output – Force

2009 ◽  
pp. 62-70 ◽  
Author(s):  
Mark de Zee ◽  
John Rasmussen
Keyword(s):  
Musculoskeletal Modeling ◽  
Output Force

Frequency Modulation of Motor Unit Discharge Has Task-Dependent Effects on Fluctuations in Motor Output

2005 ◽  
Vol 94 (4) ◽  
pp. 2878-2887 ◽  
Author(s):  
Carol J. Mottram ◽  
Evangelos A. Christou ◽  
François G. Meyer ◽  
Roger M. Enoka
Keyword(s):  
Motor Unit ◽  
Frequency Modulation ◽  
Discharge Rate ◽  
Motor Output ◽  
Unit Discharge ◽  
Rate Of Increase ◽  
Output Force ◽  
Position Task ◽  
Motor Unit Discharge ◽  
Target Force

The rate of change in the fluctuations in motor output differs during the performance of fatiguing contractions that involve different types of loads. The purpose of this study was to examine the contribution of frequency modulation of motor unit discharge to the fluctuations in the motor output during sustained contractions with the force and position tasks. In separate tests with the upper arm vertical and the elbow flexed to 1.57 rad, the seated subjects maintained either a constant upward force at the wrist (force task) or a constant elbow angle (position task). The force and position tasks were performed in random order at a target force equal to 3.6 ± 2.1% (mean ± SD) of the maximal voluntary contraction (MVC) force above the recruitment threshold of an isolated motor unit from the biceps brachii. Each subject maintained the two tasks for an identical duration (161 ± 93 s) at a mean target force of 22.4 ± 13.6% MVC. As expected, the rate of increase in the fluctuations in motor output (force task: SD for detrended force; position task: SD for vertical acceleration) was greater for the position task than the force task ( P < 0.001). The amplitude of the coefficient of variation (CV) and the power spectra for motor unit discharge were similar between tasks ( P > 0.1) and did not change with time ( P > 0.1), and could not explain the different rates of increase in motor output fluctuations for the two tasks. Nonetheless, frequency modulation of motor unit discharge differed during the two tasks and predicted ( P < 0.001) both the CV for discharge rate (force task: 1–3, 12–13, and 14–15 Hz; position task: 0–1, and 1–2 Hz) and the fluctuations in motor output (force task: 5–6, 9–10, 12–13, and 14–15 Hz; position task: 6–7, 14–15, 17–19, 20–21, and 23–24 Hz). Frequency modulation of motor unit discharge rate differed for the force and position tasks and influenced the ability to sustain steady contractions.

scholarly journals A soft, synergy-based robotic glove for grasping assistance

2021 ◽  
Vol 2 ◽  
Author(s):  
Ryan Alicea ◽  
Michele Xiloyannis ◽  
Domenico Chiaradia ◽  
Michele Barsotti ◽  
Antonio Frisoli ◽  
...  
Keyword(s):  
Daily Living ◽  
Power Transmission ◽  
Force Production ◽  
Output Force ◽  
Cord Injury ◽  
Closing Force ◽  
Block Test ◽  
Postural Synergies

Abstract This paper presents a soft, tendon-driven, robotic glove designed to augment grasp capability and provide rehabilitation assistance for postspinal cord injury patients. The basis of the design is an underactuation approach utilizing postural synergies of the hand to support a large variety of grasps with a single actuator. The glove is lightweight, easy to don, and generates sufficient hand closing force to assist with activities of daily living. Device efficiency was examined through a characterization of the power transmission elements, and output force production was observed to be linear in both cylindrical and pinch grasp configurations. We further show that, as a result of the synergy-inspired actuation strategy, the glove only slightly alters the distribution of forces across the fingers, compared to a natural, unassisted grasping pattern. Finally, a preliminary case study was conducted using a participant suffering from an incomplete spinal cord injury (C7). It was found that through the use of the glove, the participant was able to achieve a 50% performance improvement (from four to six blocks) in a standard Box and Block test.

scholarly journals Dependence of lumbar loads on spinopelvic sagittal alignment: An evaluation based on musculoskeletal modeling

PLoS ONE ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. e0207997 ◽  
Author(s):  
Tito Bassani ◽  
Gloria Casaroli ◽  
Fabio Galbusera
Keyword(s):  
Sagittal Alignment ◽  
Musculoskeletal Modeling

Design and fabrication of an electro-thermal linear motor with large output force and displacement

2016 ◽  
Author(s):  
Tengjiang Hu ◽  
Yulong Zhao ◽  
Xiuyuan Li ◽  
You Zhao ◽  
Yingwei Bai
Keyword(s):  
Linear Motor ◽  
Output Force ◽  
Large Output

Validation of hamstrings musculoskeletal modeling by calculating peak hamstrings length at different hip angles

2008 ◽  
Vol 41 (5) ◽  
pp. 1022-1028 ◽  
Author(s):  
Marjolein M. van der Krogt ◽  
Caroline A.M. Doorenbosch ◽  
Jaap Harlaar
Keyword(s):  
Musculoskeletal Modeling

Giant Magnetostrictive Actuator and Its Application in Active Vibration Control

2005 ◽  
Vol 475-479 ◽  
pp. 2089-2094
Author(s):  
Hui Bin Xu ◽  
Tian Li Zhang ◽  
Cheng Bao Jiang ◽  
Hu Zhang
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Fast Response ◽  
Coupling Factor ◽  
Output Displacement ◽  
Output Force ◽  
Magnetostrictive Actuators ◽  
Active Vibration ◽  
Magnetostrictive Actuator ◽  
Static Output

TbDyFe is a rare earth-iron magnetostrictive alloy with “giant” magnetostrain, good magnetomechanical coupling factor and fast response. Giant magnetostrictive actuators (GMAs) are designed and fabricated with home-made TbDyFe rods. Their magnetostrain properties under varied operation are tested. The static output displacement up to 100μm and output force up to 1500N were obtained. The dynamic displacement increases with amplitude under fixed frequency and decreases with frequency under fixed amplitude generally. The maximum dynamic output displacement of 146µm was obtained at natural frequency around 5Hz. Active vibration control employing GMA was implemented in the flexible structure. The excellent damping effect, 20-30 dB under the frequency range from 10Hz to 100Hz was obtained. The dynamic phase delay of GMA has been analyzed. A novel improved FSLMS algorithm is proposed to achieve a better control performance.

Design of a Compliant Mechanism to Modify an Actuator Characteristic to Deliver a Constant Output Force

2006 ◽  
Vol 128 (5) ◽  
pp. 1101 ◽  
Author(s):  
C. B. W. Pedersen ◽  
N. A. Fleck ◽  
G. K. Ananthasuresh
Keyword(s):  
Compliant Mechanism ◽  
Output Force ◽  
Constant Output

Power Output Force Generation by a MEMS Phase Change Actuator

2011 ◽  
Vol 20 (6) ◽  
pp. 1287-1297 ◽  
Author(s):  
Leland W. Weiss ◽  
Cill D. Richards ◽  
Robert F. Richards
Keyword(s):  
Phase Change ◽  
Power Output ◽  
Force Generation ◽  
Output Force

Linear Thermomechanical Microactuators

1999 ◽  
Author(s):  
Rebecca Cragun ◽  
Larry L. Howell
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Expansion ◽  
Cross Sections ◽  
Variable Cross ◽  
Element Analysis ◽  
Thermal Actuators ◽  
Output Force ◽  
Analysis Models ◽  
High Output

Abstract Thermomechanical in-plane microactuators (TIMs) have been designed, modeled, fabricated, and tested. TIMs offer an alternative to arrays of smaller thermal actuators to obtain high output forces. The design is easily modified to obtain the desired output force or deflection for specific applications. The operational principle is based on the symmetrical thermal expansion of variable cross sections of the surface micromachined microdevice. Sixteen configurations of TIMs were fabricated of polysilicon. Finite element analysis models were used to predict the deflection and output force for the actuators. Experimental results were also recorded for all sixteen configurations, including deflections and output forces up to 20 micron and 35 dyne.

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