CHAPTER 5 - SKELETAL SYSTEM Flashcards
Osteology
Study of bones
Arthrology
Study of joints
Bone’s and Joint’s mechanical and physiological functions
- Support: supports weight of body by providing a framework that allows upright posture
- Movement: allows movement by providing a rigid lever system for muscle attachment across joints
- Protection: protects internal organs and soft tissue with bony encasement
- Mineral deposits: stores required minerals in the body and maintains mineral balance in the blood
- Blood cell formation: forms red blood cells within the red bone marrow of the long bones
- Energy reservoir: stores energy in the form of fat in the yellow bone marrow and adipose tissue
Number of Bones
- 270 bones in babies
- 206 bones in the adult body
Composition of Bone
- 50% fluid, 50% solid
- In young children the long bones are mainly cartilage which allow them to be flexible and pliable (process finished by between 16-25)
- Inorganic Component: Minerals and salt (such as calcium and phosphate) provides strength and rigidity
- Organic Component: living cells, fibers, and a sticky protein. Provides pliability and flexibility.
Bone Groupings
- Long Bones
- Short Bones
- Flat Bones
- Irregular Bones
Long Bones
- Lever for movement
- Longer than they are wide
- Ex: femur and humerus
Short Bones
- Give strength to joints but with limited mobility
- Cube like bones
- Great deal of stability, strength and shock absorption and allow movement in many directions
- Ex: tarsals (ankle) and carpals (wrist)
Flat Bones
- Provide a broad site for muscle attachment and protect internal organs
- Broad, thin layers that offer protection but little motion
- Ex: skull, scapula, ribs and sternum
Irregular Bones
- Protect internal organs and support the body
- Vertebrae make up spine - long weight bearing pillar that supports mass in an upright position and functions as a site for muscle attachment and shock absorption
- Ex: ischium, pubis and vertebrae
Parts of the Skeleton
Axial skeleton and appendicular skeleton
Axial skeleton
- Skull, pim, ribs, sternum (breastbone)
- 80 bones
- Longitudinal axis of trunk to which the limbs attach
- Protects vital organs
Appendicular skeleton
- Bones of appendages (limbs), and bony girdles to which they attach
- 126 bones
Three Classifications of Joints
- Fibrous
- Cartilaginous
- Synovial
Injured Ligament
Sprain
Fibrous Joint
- Connect bones to other bones with fibrous connective tissue and allow little if any movement
- Ex: skull and pelvis are held together by fibrous joints
- Ex: radius and ulna are held in relation to each other through fibrous tissue
Cartilaginous Joint
- Bones are separated by cartilage
- Little to no movement and are found where a lot of protection, stability and strength is needed
- Ex: ribs, sternum, and between vertebrae
Synovial Joint
- Mobile and have cartilage along the surfaces where bones join to reduce friction and absorb shock
- Enclosed by an articular capsule that holds synovial fluid (lubricating fluid produced in synovial membrane) inside the joint cavity
- Three most common types are hinge, ball-and-socket and condyloid
Six Types of Synovial Joint
- Gliding
- Pivot
- Saddle
- Condyloid
- Ball and Socket
- Hinge
Gliding Joint
- Allows minimal movement in one plane with restrictions
- Ex: bones in wrist and ankle
Pivot Joint
- Allows rotation along a long axis
- Ex: radius and ulna (at the elbow) allowing pronation and supination of the forearm
Saddle Joint
- Allows movement in several directions similar to but greater than condyloid joints
- Ex: thumbs moving in multiple directions
Hinge Joint
- Movement in one direction or plane of motion
- Ex: elbow and knee joints allowing flexion and extension
Condyloid Joint
- Allows movement in two different directions or planes of motion
- Ex: knuckles in each finger and in the wrist and ankle
Ball and Socket Joint
- Allows movement in three directions
- Ex. Shoulder and hip joint allowing free movement in all directions
Three Cardinal Planes of Motion
- Frontal plane: anterior and posterior
- Sagittal plane: left and right side
- Transverse plane: Superior (above) and inferior (below)
Frontal plane
- Anterior and posterior
- Abduction and adduction
- Ex: lat raise
Sagittal plane
- Left and right side
- Flexion and extension
- Ex: squat
Transverse plane
- Superior (above) and inferior (below)
- Twisting and rotation
Anterior
Front
Posterior
Back
Medial
Closer to Midline
Lateral
Farther from Midline
Superior
Above
Inferior
Below
Supine
Face Up
Prone
Face Down
Dorsal
Top of Foot
Plantar
Bottom of Foot
Proximal
End of bone or muscle that is closer to midline of body (torso)
Distal
End of bone or muscle that is farther from body
Flexion
Bending a joint (angle decreases)
Extension
Straightening a joint (angle increases)
Hyperextension/hyperflexion
Flexion or Extension beyond normal range of motion
Abduction (protraction)
Bone moves away from midline of body
Adduction (retraction)
Bone moves back towards midline of body
Circumduction
- Circular movement
- Combination of flexion, extension, abduction and adduction
Elevation
- Shrugging shoulders
- Scapular elevation
Depression
- Lowering shoulders below anatomical position
- Scapular retraction
Medial (internal) rotation
Towards midline
Lateral (external) rotation
Away from midline
Supination
External movement (palms face up)
Pronation
Internal movement (palms face down)
Inversion
- Ankle joint
- Medial or inner side turned off ground
Eversion
- Ankle joint
- Lateral or outer side turned off the ground
Dorsi flexion
Flexing foot upward
Plantar flexion
Flexing foot downward
Four Major Spine Segments
- Cervical spine: neck
- Thoracic spine: upper back
- Lumbar spine: lower back
- Sacral spine: bottom of spine
One other minor section
Coccyx (tailbone)
The Core
- Spans from the ribcage to the pelvis
- Important in load carriage and spinal nerve root protection and it provides the foundation from which forces are transmitted from the upper body to the lower body and vise-versa
Core Stability Subsystems
Passive - bones and ligaments within the spinal column
Active - muscles act on the spine
Control - managed by nervous system
Lower Back Pain
- Pain localized between the rib cage and buttocks
- ¾ of the population will experience lower back pain at some point in their life that will limit them from performing some of their daily tasks
- Causes are stain, overextension, irregular or unsafe performance of movement such as lifting, pushing, pulling, turning, twisting or bending. These show dysfunctions and active (muscle) and passive (joint) subsystems
- Most common causes of pain pain that originated from passive stabilization system include herniated discs, disc degeneration, facet joint inflammation and ligament damage
General Precautions in Reference to the Back
- Pay close attention to posture, alignment and form during exercise
- Include exercises to help strengthen and stabilize the core
- Good posture involves a balance between flexion and extension
