Download Force vs. Length

Introduction
Modeling the
Musculoskeletal Biomechanics
of the Human Arm
B.E.A.R.S Presentation
Brian A. Garner
Assistant Professor
Department of Engineering
Textbook pictures from:
Nigg, Benno M. and Herzog, W., Biomechanics
of the Musculoskeletal System 2nd edition,
Chichester and New York: Wiley, 1999
Anatomy pictures from:
Marieb, Elaine N., Human Anatomy & Physiology 4th
edition, Addison Wesley Longman, Inc. 1998
Musculoskeletal Modeling
Model represents:
• Bone and Joint Mechanics/Dynamics
• Muscle Lines-of-Action
• Muscle Physiological Properties
• Muscle Activation Dynamics
Model calculations:
Acceleration
Force
F=M*A
A=F/M
Force
Acceleration
Anatomical Database
Medical Images from Visible Human Project:
CT Images
Cryo-Section Images
Anatomical Database
3D Image Reconstruction:
Anatomical Database
Reconstructed Bones and Muscles
Skeletal Anatomy of Arm
Clavicle
Clavicle
Scapula
Humerus
Scapula
Ulna
Radius
Carpals
Metacarpals
Phalanges
Skeletal Anatomy of Arm
Clavicle
Scapula
Humerus
Ulna
Ball-and-Socket Joint Behavior
Radius
Carpals
Metacarpals
Phalanges
Shoulder Joint Model
Skeletal Anatomy of Arm
Clavicle
Scapula
Humerus
Ulna
Radius
Carpals
Metacarpals
Phalanges
Revolute (Hinge) Joint Behavior
Forearm Joints
Scapulothoracic Articulation
Clavicle
Scapula
Musculoskeletal Modeling
Model represents:
• Bone and Joint Mechanics/Dynamics
• Muscle Lines-of-Action
• Muscle Physiological Properties
• Muscle Activation Dynamics
Model calculations:
Acceleration
Force
F=M*A
A=F/M
Force
Acceleration
Muscular Anatomy of Arm
Muscular Anatomy of Arm
Muscular Anatomy of Arm
Muscle Force Action
Hypothetical Muscle:
Hypothetical Model:
Muscle Path Obstacle Models
Muscle Force Action
• Reconstructed Muscle
• Centroid Line-of-Action
• Modeled Muscle Path
Muscle Force Action
Other Modeled Muscle Paths:
Muscle Force Action
Shoulder Muscles:
Forearm Muscles:
Muscle Force Action
Supraspinatus
A
Moment Arm (mm)
40
Biceps Brachii
B
Moment Arm (mm)
60
50
Hughes
30
Lemay
(Short)
(Long)
40
Liu
20
30
Murray
An
10
20
0
10
-10
0
0
15
30
45
60
Abduction Angle (deg)
75
90
0
15
30
45
60
75
90
105
Flexion Angle (deg)
120
135
150
Musculoskeletal Modeling
Model represents:
• Bone and Joint Mechanics/Dynamics
• Muscle Lines-of-Action
• Muscle Physiological Properties
• Muscle Activation Dynamics
Model calculations:
Acceleration
Force
F=M*A
A=F/M
Force
Acceleration
Muscle Physiology
Muscle Physiology
Muscle Physiology
Muscle Physiology
Muscle Physiology
Muscle Physiology
Modeling Muscle Physiology
Physiological Parameters:
Force vs. Length
maximum
isometric
force
optimal muscle
fiber length
pennation
angle
rest length of tendon
Modeling Muscle Physiology
Optimization of Parameters:
Modeling Muscle Physiology
(A)
Shoulder Abduction Torque (Nm)
150
(B)
Elbow Flexion Torque (Nm)
100
Flexion
80
Abduction
100
60
40
50
Amis (1979)
Knapik (1983)
20
0
Hutchins (1993)
0
Otis (1994)
Reiser (1993)
-50
-20
-40
-60
-100
-80
Adduction
-150
Extension
-100
0
15
30
45
60
75
Glenohumeral Abduction Angle (deg)
90
0
30
60
90
120
Elbow Flexion Angle (deg)
150