1. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Shoulder active motion simulator. Photograph of simulator with a right shoulder mounted. Note the low friction pneumatic actuators (a), low friction cable guides (b), mass replacement system (c), optical trackers on the humerus and scapula (d), adjustable scapula pot (e), and DC servomotor and linkage system which drives scapular rotations (f).

2. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Control system flow diagram. Diagram illustrates the system's input and output variables and how data flows through it. Note that dashed black arrows denote kinematic inputs; gray arrows indicate ratio based data (i.e., input muscle loading ratios or muscle force distributions output from a PID) and gray boxes are operations (i.e., PID control loops) with ratio outputs; solid black arrows indicate force values and solid black boxes indicate operations which produce or modulate a force command.

3. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Example muscle loads produced by motion controller. Shown are a set of muscle loads produced during abduction in the scapular plane for an intact shoulder. Note that in this specimen, 55 deg glenohumeral abduction combined with scapular rotation corresponded to the arm parallel to the ground.

4. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Abduction and horizontal extension profiling accuracy and repeatability. (a) Accuracy of the simulator in following a predefined abduction profile in the scapular plane. The profile begins at the resting position (∼10 deg) and ends with the arm parallel to the ground. (b) Accuracy of the active motion simulator in following a predefined horizontal extension profile with the arm parallel to the ground and externally rotated. The profile begins with the humerus in the scapular plane and ends 35 deg posterior. The “difference” series on the secondary axis is the difference between the profile and resulting motion. The thin black standard deviation lines across the motion demonstrate the system’s high repeatability.

5. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Effect of variations in specimen’s size-to-mass ratio. Shown is the simulator’s response to a ±40% change in the specimen’s mass which is used to replicate subjects with varying size-to-mass ratios (i.e., BMI). The dashed lines represent the respective setpoint profiles for this abduction motion while the solid lines are the resulting motions.

6. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Effect of varying proportional and integral gains on controller characteristics. (a) Response of a proportional only controller and how response varies with increasing gain values during abduction in the scapular plane. Graphs (b) and (c) demonstrate the effects of increasing the integral time component of the “optimal” PID controller during abduction and horizontal extension, respectively. Similarly, (d) and (e) demonstrate the effects of decreasing integral time during abduction and horizontal extension, respectively.

7. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Simulator’s response to scapular disturbance. This graph demonstrates the simulator’s ability to minimize the effect of disturbances, and quickly reject any disturbance in glenohumeral orientation. Note that the Disturbance data series is plotted on the secondary axis.

8. Date of download: 10/27/2017
Copyright © ASME. All rights reserved.
From: Development and Performance Evaluation of a Multi-PID Muscle Loading Driven In Vitro Active-Motion Shoulder Simulator and Application to Assessing Reverse Total Shoulder Arthroplasty
J Biomech Eng. 2014;136(12): doi: /
Figure Legend:
Total deltoid muscle force for varying levels of glenosphere lateralization. Shown are the total deltoid loads for varying reverse total shoulder glenosphere lateralization levels. These data demonstrate that the simulator’s controller is sensitive to changes in joint geometry.