PTHA 1513FUNCTIONAL ANATOMY

Week 1: Lecture 2 Elaine Wilson, PT

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Today’s Theme Song 2

Welcome to the Spring Semester!!!

I LOVE THESE KIDS!!!3

Goals for Today4

Define commonly used anatomic and kinesiologic terminology

Describe common movements of the body

Analyze the planes of motion and axes of rotation for common motions

Differentiate between osteokinematic and arthrokinematic movement

Describe arthrokinematic principles of movement

Goals for Today - cont’d

Describe how force, torque, and levers affect biomechanical movement

Describe the three biomechanical lever systems, and explain their advantages and disadvantages

Analyze how muscular lines of pull produce specific biomechanical motions

Explain how muscular force vectors are used to describe movement

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Medical students at the dissection table in Anatomy lab.Medical College of Virginia, class of 1903

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CHAPTER 1Basic Principles of Kinesiology

Kinematics: Motion of a body without regard to forces8

Translation Rectilinear motion (straight line) Curvilinear motion (curved line)

Rotation (movement of body about an axis) Active movements

ex, flexing an arm over the head Passive movements

ex, limb moving without muscle contraction

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Kinesiology Terminology9

Anterior: toward the front of the body Posterior: toward the back of the body Midline: an imaginary line that courses

vertically through the center of the body Medial: toward the midline of the body Lateral: away from the midline of the

body Superior: above, or toward the head

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Kinesiology Terminology – cont’d

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Inferior: below, or toward the feet Proximal: closer to, or toward the

torso Distal: away from the torso Cephalad: toward the head Caudal: toward the feet, or “tail” Superficial: toward the surface (skin)

of the body

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Kinesiology Terminology – cont’d

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Deep: toward the inside (core) of the body

Origin: the proximal attachment of a muscle or ligament

Insertion: the distal attachment of a muscle or ligament

Prone: describes the position of an individual lying face down

Supine: describes the position of an individual lying face up

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Osteokinematics: Motion of bones relative to 3 cardinal planes12

Planes of motion Sagittal plane: left-right division Frontal plane: front-back division Horizontal (transverse) plane: top-

bottom division Anatomic position Degrees of freedom

Number of planes of motion joint allows

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Osteokinematics – cont’d13

Axes of rotation Anterior-posterior

e.g., hip abduction/adduction Medial-lateral

e.g., elbow flexion/extension Vertical (longitudinal)

Rotational movements, e.g., trunk rotation

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Osteokinematics: Body Motions

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Motion of one bone approaching the flexor surface of another

Extension An approximation of the extensor

surfaces of two bones Abduction

Frontal plane movement away from the midline

Adduction Frontal plane movement toward the

midline

Osteokinematics: Body Motions – cont’d

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Rotation: Bony segment spinning about its longitudinal axis of rotation Internal rotation

Anterior bone surface rotates toward the midline

External rotation Anterior bone surface rotates away from the midline 

Circumduction A circular motion through two planes

Osteokinematics: Body Motions – cont’d16

Protraction Translation of bone away from

midline in a plane parallel to the ground

Retraction Movement of a bony segment

toward the midline in a plane parallel to the ground

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Osteokinematics: Body Motions – cont’d

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Horizontal adduction and abduction Shoulder motions in the transverse plane Horizontal adduction: hands come together Horizontal abduction: extremities move away

from midline Pronation

Forearm movement that turns the palm posteriorly

Supination Forearm movement that turns the palm

anteriorly

Osteokinematics: Body Motions – cont’d

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Radial deviation Lateral hand movement toward the radius

Ulnar deviation Medial hand movement toward the ulna

Dorsiflexion Sagittal plane ankle motion bringing the

foot upward

Plantar flexion Sagittal plane ankle motion pushing the

foot downward

Osteokinematics: Body Motions – cont’d

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Inversion and eversion Frontal plane motions of the

ankle/foot complex Inversion results in a medial-

facing foot sole Eversion results in a lateral-facing

foot sole

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Osteokinematics: It’s All Relative

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Two perspectives of movement at a joint Open-chain motion

Movement of distal segment of bone about a relatively fixed proximal segment

Closed-chain motion Movement of proximal segment of

bone about a relatively fixed distal segment

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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Arthrokinematics: Arthrokinematics

Motion occurring between joint articular surfaces

Convex-concave joint relationship Improves fit (congruency) and stability Properly guides motion

Fundamental movements of arthrokinematics vary Depend on whether concave articular surface is

moving on a fixed convex surface or vice versa

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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Arthrokinematics: Fundamental Movements between Joint Surfaces Roll

Multiple points along one rotating articular surface contact multiple points on another articular surface Ex: a tire rotating across a stretch of

pavement Slide

Single point on one articular surface contacts multiple points on another articular surface Ex: a stationary tire skidding across a

stretch of icy pavementMosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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Arthrokinematics: Fundamental Movements between Joint Surfaces – cont’d

Spin Single point on one articular

surface rotates on a single point on another articular surfacee.g., rotating toy top spinning on one spot on the floor

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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Arthrokinematics: Mechanics and Functional Considerations Roll-and-slide mechanics Roll–and–opposite-direction slide maintains

articular stability To maintain firm surface contact, motion must

be accompanied by slide in same direction Spin mechanics

Spin always occurs about a central longitudinal axis of rotation

Functional considerations Motion may be hindered by issues like

impingement syndrome

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Kinetics

Branch of mechanics that describes the effect of forces on the body

Force “Push or pull” that can produce,

modify, or halt a movement Internal force is generated within the body

External force is generated outside the body

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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Kinetics: Torque

Torque is the rotational equivalent of force Amount generated across a joint depends

on: Amount of force exerted Distance between force and axis of

rotation (moment arm) Internal torques are generated internally

(ex: muscle) External torques are generated externally

(ex: gravity)Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

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Kinetics: Biomechanical Levers

First-class lever Similar to a see-saw; fulcrum located

between internal and external force Second-class levers

Axis of rotation located at one end of the bony lever; internal moment arm always longer than the external moment arm

Third-class levers Axis of rotation located at one end of the bony lever;

internal moment arm always smaller than the external moment arm

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Kinetics: Line of Pull Line of pull describes the direction of muscular force

Medial-lateral axis of rotation Bony motion anterior of the sagittal plane

Anterior-posterior axis of rotation Lateral motion pulls bone laterallyMedial motion pulls bone medially

Vertical axis of rotation Anterior or medial pull produces inward rotationPosterior or lateral pull produces rotation away

from the midline

Mosby items and derived items © 2009 by Mosby, Inc., an affiliate of Elsevier Inc.

Homework

Read Chapter 2: Essentials of Kinesiology for the PTA prior to Tuesday 01/24/12 lecture at 9am.

Prepare for Quiz – 9am 01/24/12 (covering Chapters 1 and 2 of Essentials of Kinesiology for the PTA)

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