CHAPTER 2:PART 1
MUSCULOSKELETAL SYSTEM:
FRAMEWORK AND MOVEMENTS
KINESIOLOGY
Scientific Basis of Human Motion, 12th edition
Hamilton, Weimar & Luttgens
Presentation Created by
TK Koesterer, Ph.D., ATC
Humboldt State University
Revised by Hamilton & Weimar
McGraw-Hill/Irwin
Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.
OBJECTIVES
1. Classify joints according to structure, and explain the relationship
between a joint structure and its capacity for movement.
2. Explain how the schedule of ossification of epiphyseal cartilage is
related to the nature of activities suitable for different age
groups.
3. Name the factors that contribute to joint range of motion and
stability, and explain the relationship that exists between range
of motion and stability.
4. Assess a joint’s range of motion, evaluate the range, and describe
desirable procedures for changing it when indicated.
5. Name and define the orientation positions and planes of the body
and the axes of motion.
6. Demonstrate and name fundamental movement patterns using
correct movement terminology.
7. Isolate and name single joint actions that are part of complex
movements.
8. Perform an anatomical analysis of the joint actions and planes of
motion for a selected motor skill.
2-2
MUSCULOSKELETAL FRAMEWORK





An arrangement of bones, joints, and muscles.
Acts as a lever system allowing for a great
number of coordinated movements.
An anatomical lever is a bone that engages in
movement when force is applied to it.
The force is from a muscle attached to the
bone or an external force (gravity or weight).
Muscles can produce motion only by
shortening.
2-3
THE BONES



Skeleton: provides
support, muscle
attachment, &
protection
Axial: skull, spinal
column, sternum, and
ribs
Appendicular: upper
and lower extremities
Fig 2.1
2-4
THE BONES:
SKELETAL CHANGES

Growth





Osteogenesis
Initial matrix
Osteoblasts form bone on matrix.
Bone forms in response to loading stress.
Degeneration


Osteoclasts reabsorb bone in the absence of stress.
Bones become more porous and brittle; osteoporosis.
2-5
THE BONES:
Bone types
Two types allow bone to be
strong, yet light.

 Compact:
dense outer
bone
 Cancellous: open, spongy
looking inner bone
Fig. 2.2
2-6
TYPES OF BONES

Long: shaft or body with a medullary canal,
and relatively broad, knobby ends


Short: relatively small, chunky, solid


Carpals and tarsals
Flat: flat & plate like


Femur, tibia, humerus, ulna, radius, etc.
Sternum, scapulae, ribs, pelvis
Irregular: bones of spinal column

Vertebrae, sacrum, & coccyx
2-7
MECHANICAL AXIS OF A BONE
A straight line that
connects the midpoint of
the joint at one end of a
bone with the midpoint of
the joint at the other end.
 The axis may lie outside
the shaft.

Fig 2.3
2-8
SKELETAL CHANGES





Epiphysis is a part of a bone separated from the main
bone by a layer of cartilage.
Epiphyseal cartilage is where growth occurs.
When this cartilage ossifies and closure is complete,
no more growth can occur.
Tables 2.1 & 2.2: ages of ossification
Need to be aware of epiphyseal injuries in children &
adolescents.
2-9
ARTICULATIONS
Structure and function of joints are so
interrelated that it is difficult to discuss them
separately.
 The configuration of the bones that form an
articulation, together with the reinforcing
ligaments, determine and limit the
movements of the joint.

2-10
STRUCTURAL CLASSIFICATION

Based on presence or absence of a joint cavity:
 Diarthrosis

or Synarthrosis
Further classified either by shape or nature of
the tissues that connect the bones.
2-11
DIARTHROSIS: CHARACTERISTICS
Articular cavity
 Ligamentous capsule
 Synovial membrane
 Surfaces are smooth
 Surfaces covered
with cartilage

Fig 2.5
2-12
DIARTHROSIS: CLASSIFICATION






Irregular joint: irregular surfaces, flat or slightly curved,
permits gliding movement.
Hinge joint: convex/concave surfaces, uniaxial, permits
flexion/extension.
Pivot joint: a peg-like pivot, permits rotation.
Condyloid joint: oval or egg-shape convex surface fits into a
reciprocal concave surface, biaxial, permits flexion/extension,
ab & adduction, and circumduction.
Saddle: modification of condyloid, both surfaces are convex
and concave, biaxial, permits flexion/extension, ab &
adduction, and circumduction.
Ball-and-socket: head of one bone fits into the cup of the other
bone.
2-13
TYPE OF JOINTS
Plane
Intercarpal
Condyloid
MCP joint
Hinge
Elbow
Saddle
Thumb
Pivot
Atlantoaxial
Ball & Socket
Shoulder
Condyloid
Radiocarpal
Ball & Socket
Hip
2-14
SYNARTHROSIS: CHARACTERISTICS
No articular cavity, no capsule, synovial
membrane or synovial fluid.
 In two types, bones are united by cartilage or
fibrous tissue.
 Third type, not a true joint, but is a ligamentous
connection between bones.

2-15
SYNARTHROSIS: CLASSIFICATION
Cartilaginous joint: united by fibrocartilage
permits bending & twisting motions.
 Fibrous joint: edges of bone are united by a thin
layer of fibrous tissue, no movement permitted.
 Ligamentous joints: two bodies are tied
together by ligaments, permits limited
movement of no specific type.

2-16
JOINT STABILITY





Function of joints is to provide a means of moving or, rather, of being
moved.
Secondary functions is to provide stability without interfering with the
desired motions.
 All joints do not have the same degree of stability.
Emerson’s law: “For everything that is given, something is taken”.
 Movement is gained at the expense of stability.
Resistance to displacement
Factors responsible for stability
 Bony structure
 Ligamentous arrangement
 Muscle tension
 Fascia
 Atmospheric pressure
2-17
SHAPE OF BONY STRUCTURE

May refer to kind of joint:
 Hinge,

condyloid, pivot, or ball-and-socket
Or specific characteristics of a joint:
 Depth
of socket
More stable,
less mobile
More mobile,
less stable
2-18
LIGAMENTOUS ARRANGEMENTS
Ligaments are strong, flexible, stressresistant, somewhat elastic, fibrous tissues
that form bands or cords.
 Join bone to bone.
 Help maintain relationship of bones.
 Check movement at normal limits of joint.
 Resist movements for which joint is not
constructed.
 Will stretch when subject to prolonged stress.


Once stretched, their function is affected.
2-19
MUSCULAR ARRANGEMENT
Muscles that span joints
aid in stability.
 Especially when bony
structure contributes
little to stability.

Fig 5.13
Muscles acting to stabilize the
shoulder
2-20
FASCIA AND SKIN
Fascia consists of fibrous connective tissue.
 May form thin membranes or tough, fibrous
sheets.
 Intense or prolonged stress may cause
permanent stretch.
 Iliotibial tract and thick skin covering the knee
joint are examples.

2-21
ATMOSPHERIC PRESSURE
Negative pressure in joint capsule forms a
vacuum.
 The suction created is an important factor in
resisting dislocation of a joint.
 Key in hip and shoulder joints.

2-22
FACTORS AFFECTING THE RANGE OF MOTION
(ROM)



Three factors that affect the stability of a joint are also
related to its ROM:
1. Shape of articular surfaces.
2. Restraining effect of ligaments.
3. Muscles and tendons (single most important
factor).
Flexibility should not exceed muscle’s ability to
maintain integrity of joint.
Additional factors include: injury or disease, gender,
body build, heredity, occupation, exercise, and age.
2-23
METHODS OF ASSESSING A JOINT’S RANGE OF
MOTION
Measure degrees from starting position to its
maximal movement.
 Goniometer: axis placed directly over center
of joint, one arm held stationary, other arm
held to moving segment.

Fig 2.7
2-24
METHODS OF ASSESSING A JOINT’S RANGE OF
MOTION
Videotape: joint centers are
marked to be visible in
projected image.
 Joint angles can be taken
from images.
 Segment action must occur
in picture plane.

Fig 2.8
91°
85°
2-25
AVERAGE RANGES OF JOINT MOTION
Ranges vary and it is difficult to establish
norms.
 Age, gender, body build, and level of activity
may all be factors.
 Four sets of ranges are presented in table
2.4.
 Illustration of joint ROM for most
fundamental movements are found in
Appendix B.

2-26
ORIENTATION OF THE BODY
 Center
of Gravity: imaginary point
representing the weight center of an object
 Line
of Gravity: imaginary vertical line that
passes through the center of gravity
2-27
ORIENTATION OF THE BODY
PLANES OF THE BODY
Fig
2.8
Sagittal
Frontal
Transverse
2-28
ORIENTATION OF THE BODY
AXES OF MOTION





Bilateral: axis passes horizontally from side to side;
perpendicular to sagittal plane.
Anteroposterior or AP: axis passes horizontally from
front to back; perpendicular to frontal plane.
Vertical: axis is perpendicular to the ground and
transverse plane.
Rotation occurs in a plane and around an axis.
Axis of movement is always at right angles to the
plane in which it occurs.
2-29
ORIENTATION OF THE BODY
STANDARD STARTING POSITIONS
Fig 2.10
Fundamental
Standing
Position
Anatomical
Standing
Position
2-30
FUNDAMENTAL MOVEMENTS
SAGITTAL PLANE ABOUT A BILATERAL
AXIS
Flexion: reduction in joint angle.
 Examples:





Tipping the head forward
Lifting the foot & leg backward from knee
Raising entire lower extremity forward-upward
as though kicking
Raising forearm straight forward
Elbow straight, raising entire upper extremity
forward-upward
2-31
FUNDAMENTAL MOVEMENTS
SAGITTAL PLANE ABOUT A BILATERAL
AXIS
Extension: return movement from flexion.
Hyperflexion: arm is flexed beyond vertical.
Hyperextension: continuation of extension
beyond starting position.
Reduction of Hyperextension: return
movement from hyperextension.
2-32
JOINT MOTIONS IN THE SAGITTAL PLANE AROUND A BILATERAL
AXIS.
2-33
FUNDAMENTAL MOVEMENTS
FRONTAL PLANE ABOUT AN AP AXIS
Abduction: movement away from the midline.
Adduction: return movement from abduction.
Lateral Flexion: lateral bending of head or trunk.
Hyperabduction: arm abducted beyond vertical.
Hyperadduction: move across in front of the body.
Reduction of Hyperadduction: return movement.
Reduction of Lateral Flexion: return movement.
2-34
JOINT MOTIONS IN THE FRONTAL PLANE AROUND AN ANTEROPOSTERIOR AXIS.
2-35
FUNDAMENTAL MOVEMENTS
TRANSVERSE PLANE ABOUT A VERTICAL
AXIS
(Point of reference for the upper extremities is the midpoint
of the fundamental (not anatomic) position.)
Rotation Left & Right: rotation of head, neck, or
pelvis.
Lateral & Medial Rotation: rotation of thigh and
upper arm.
Supination & Pronation: rotation of forearm along
long axis.
Reduction of Lateral Rotation, Medial Rotation,
Supination, or Pronation: rotation of segment
back to mid-position.
2-36
TORSO MOTION IN THE TRANSVERSE PLANE AROUND A
VERTICAL AXIS.
2-37
FUNDAMENTAL MOVEMENTS
COMBINATION OF PLANES
Circumduction: whole segment describes a
cone.

arm circling and trunk circling
2-38
NAMING JOINT ACTION IN COMPLEX
MOVEMENTS
All joint actions are named as if they were
occurring in anatomical position.
 The plane and axis are identified as those in
which the movement actually occurs.

Non-axial Movements
Movements in plane joints are non-axial
gliding movements between articular facets
of spinal column.
2-39
ANALYZING JOINT MOTIONS
Alignment: optimum alignment should be
based on efficiency, effectiveness, and
safety.
 Range of Motion: ROM demands of an
activity must be compatible to avoid injury.
 Flexibility: reduces internal resistance to
motion.

2-40
ANATOMICAL ANALYSIS OF THE STANDING LONG
JUMP: (PREPARATION PHASE)
Joint
Joint
Action
Segment
moved
Plane /
Axis
Ankle
flexion
Shank
Sagittal/
bilateral
Knee
Flexion
Thigh
Sagittal/
bilateral
Hip
Flexion
Trunk
Sagittal/
bilateral
Shoulder
HyperExtension
Upper arm
Sagittal/
bilateral
Elbow
Extension
Lower arm
Sagittal/
bilateral
Force
Contraction
type
Prime
movers
2-41
ANATOMICAL ANALYSIS OF THE STANDING LONG
JUMP: (POWER PHASE)
Joint
Joint
Action
Segment
moved
Plane /
Axis
Ankle
Extension
Shank
Sagittal/
bilateral
Knee
Extension
Thigh
Sagittal/
bilateral
Hip
Extension
Trunk
Sagittal/
bilateral
Shoulder
Flexion
Upper arm
Sagittal/
bilateral
Elbow
Extension
Lower arm
Sagittal/
bilateral
Force
Contraction
type
Prime movers
2-42