Tissue Healing

  1. Three types of forces
    • Shear: opposite directions
    • Tensile: both directions
    • Compressive: same direction
  2. Compressive Force
    • Naturally occurring forces
    • force applied perpendicular to articulating surface
    • Weight Bearing In LE's or with muscle contractions
    • Therapeutically called "joint Approximation"
    • Good for joint to a point
    • Increase osteoblastic activity
  3. Tensile Forces
    • Foce applied perpendicular to the joint surface
    • Therapeutically called "distraction" used in mobilization and ROM activities
  4. Shear Forces
    • Force is parallel to the joint surface
    • When load is applied there will be a combination of approximation and shear
    • If force applied at an angle and not perpendicular it will add shear - this can lead to injury
  5. Connective Tissue
    • Bone
    • SKin
    • Ligaments
    • tendons
    • Fascia
    • Tissue make up and orientation gives it it's strength and ability to withstand different forces
  6. Structural Components of Connective Tissue
    • cellular
    • Fibrous
    • Ground
  7. Cellular Component
    • Fibroblast and fibrocytes
    • produce fibers of connective tissues and specialized cells
  8. fibrous component
    • Collagen fibers: responsible for strength and stiffness
    • Elastin: flexibility and extensibility
    • Reticulin fibers: provide bulk to connective tissue
  9. Ground Substance
    • Fluid component of tissues
    • Serves to: reduce friction between fibers
    • form lkinks between collagen fibers
    • resists compressive forces
    • helps dissipate tensile forces
  10. Strength
    • Collagen is 5 times stronger than elastin
    • increased collagen= increased strength and decreased flexibility
    • Increased elastin = greater flexibility and decreased strength
  11. Orientation of fibers
    • Parallel: Resists tensile forces in that direction (tendon)
    • Random: withstand forces in a varisty of diretions (ligaments in foot)
  12. Stress-strain curve
    Mechanical response of a selected internal structure to a deforming stress can be graphically representaed
  13. Stress
    Magnitude of force of load being applied to internal structure
  14. Strain
    amount of deformation that occures to the structure in reponse to stress applied
  15. Elastic Range
    Structure can return to original shape after deforming load
  16. Yield Point
    Point between elastic and plastic where changesa from one to the other
  17. Plastic range
    the ability of a structure being loaded to permanently obtain a new length after load is removed
  18. Failure point
    Tissue is unable to withstand anymore load without damage
  19. Mechanical failure
    • Injury
    • Point to where stress is too excessive and reaches a point at which internal structure can't withstand it
  20. Remodeling of Bone
    • Ongoing preocess thoughtout life adjust to stresses presented in everyday life
    • Osteoblast - build up bone
    • Osteoclast - break down bone
  21. Wolffs law
    • Law is the phenonmenon that describes the remodeling of bone occuring in reponse to physical stress
    • Bone will be desposited and align along lines of stress and reasborbed or no stress is present
    • have to have stess on bone inorder for it to grow
  22. Bone Deposition
    • Developmentally if unable to weight bear will have difficulty maturing sufficiently
    • need to weight bearing activities as we grow
  23. Recovery after fracture
    Bone developed throught early closed chain approximation activities
  24. Effects of Immobilization
    • Muscle: loss of strength, loss of muscle size and decreased in tension per unit of muscle cross sectional area
    • Connective Tissue: fibrosis and tightening
  25. Ligament Sprain Grades
    • Grade 1: microscopic tear, no joint laxity
    • Grade 2: tearing of some fibers, moderate laxity (5-10mm)
    • Grade 3: near complete or complete rupture progound laxity, unstable (greater than 10mm)
  26. Ligament Healing
    • Three key conditions must be present for ligaments to properly remodel or heal
    • Torn ligament ends must be in contact wiht each other
    • Progressive contreolled stress must be applied to the healing tissue to orient scar tissue formation
    • the ligament must be protected against excessive forces during the remodeling phase
  27. Ligament effects of immobilization
    • Joint stiffness immobilizaion is related to adhesion formation active shortening of dense connective tissue and decreases in water contect
    • gradual deterioration in ligament strength, loss of bone, weakenin gor cartilage and tendons, significant muscles atrophy and negatie effects on joint mechanics
  28. Muscle disorders
    • Occur within the contractile unit
    • Consists of the muscle belly, the musulotendinous junction, the tendon and the tendons bony attachemnt
    • Tendons heal slow
  29. Grades of Muscle Strains
    • Grade 1: less the 50% of damage
    • Grade 2: more than 50% damage
    • Grade 3: complete tear
    • also caleed muscles stress, pull or rupture
Card Set
Tissue Healing