Download continued - Human Kinetics

C H A P T E R
3
Functional Anatomy
and Biomechanics
Jean Lewis and Clare E. Milner
Chapter 3
Skeletal Anatomy
• 200 distinct bones
• Two types
• Cortical (compact): hard outer layer
• Trabecular (cancellous): lightweight, lattice-like
structure for internal strength
(continued)
Skeletal Anatomy (continued)
• Four classifications of bone
• Long bones (limbs, digits) (see figure 3.1)
• Short (tarsals, carpals)
• Flat (ribs, ilia)
• Irregular (ischium, pubis, vertebrae)
• Sesamoid bone: bones embedded in a tendon
(patella)
Figure 3.1
Ossification of Bones
• Begins at diaphysis of long bones
• Epiphyseal plates: growth areas where
cartilage is replaced by bone
• Additional cartilage is laid down to be
replaced by bone during growth
• Most bones ossify sometime in the late
teens
• Premature losing (shorter bones)
Figure 3.2
Planes and Axes of Movement
• Rotation is made about 1 or more of 3 axes
• Mediolateral axis (flexion and extension)
• Anteroposterior axis (abduction and adduction)
• Longitudinal (vertical) axis (internal and external rotation)
• Movement is seen in 1 of 3 cardinal planes
• Side view (sagittal plane)
• Front and back view (frontal, or coronal, plane)
• Top view (transverse plane)
Anatomical Position and
Planes of Movement (figure 3.3)
Structure and Function of Joints
• Synarthrodial (immovable): cranial bones
• Amphiarthrodial (slight movement)
• Usually have a disc separating the bones
• Joints between the bodies of the vertebrae
(continued)
Structure and Function of Joints
(continued)
• Diarthrodial (freely moveable)
• Also called synovial
• Enclosed by an articular capsule, lined by synovial
membrane
• Connective tissue connecting bone to bone
Factors Determining Direction and
Range of Motion
• Shape of bone at articulating ends
• Length of ligaments
Specific Joint Movements
• Flexion
• Extension
• Abduction
• Adduction
• Internal rotation
• External rotation
Nontraditional Joint Movements
(e.g., shoulder girdle)
• Elevation
• Depression
• Protraction
• Retraction
• Upward and downward rotation
Figure 3.4
Figure 3.5
Figure 3.6
Figure 3.7
Figure 3.8
Figure 3.9
Figure 3.10
Figure 3.11
Figure 3.12
Figure 3.13
Figure 3.14
Skeletal (Voluntary) Muscle
• Consists of muscle fibers and connective
tissue
• Tendon is the passive part of the muscle
• Size and shape vary, depending on function of
muscle
Figure 3.15
Forces That Cause Movement
• Muscle shortening
• Depends on force developed against resistance
from other forces
• Gravity
Forces That Resist Movement
• Gravity
• Soft tissue restriction
• Exercise bands
• Hydraulic or air-pressure devices
• Resistance of training equipment
• Drag of air or water
Muscle Action
• Concentric
• Shortening
• Causes movement
• Eccentric
• Length increases under tension
• Slows movement
• Agonist
• Prime movers that cause joint movement
• Antagonist
• Muscles that lengthen during concentric action
(continued)
Figure 3.16
Muscle Action (continued)
• Ballistic movements
• Resistance is minimal
• Burst of concentric action
• Isometric action
• Static (muscle exerts force equal in magnitude to
opposing force)
• Little or no change in muscle length; no movements
Figure 3.17
Role of Muscles
• Cause movement
• Decelerate movement
• Stabilize or prevent movement
• Counter undesirable movement
• Guide movements
Figure 3.18
Figure 3.19
Figure 3.20
Figure 3.21
Figure 3.22
Figure 3.23
Figure 3.24
Figure 3.25
Figure 3.26
Figure 3.27