The Bones and Soft Tissue

1. The Bones and Soft Tissue

2. Bones • Consist of osteocytes (mature bone cells) • Made of: • 35% organic material • 65% inorganic mineral salts, and water

3. Bones (cont’d.) • Formation: • Initially consists of collagenous protein fibers secreted by osteoblasts • During embryonic development, cartilage is deposited between fibers • During the eighth week of embryonic development, ossification begins • Mineral matter starts to replace previously formed cartilage, creating bone

4. Injury to Bones • Fractures • Simple or closed • Compound or open • Comminuted • Stress • Epiphyseal plate

5. Injury to Bones (cont’d.) • Fracture signs and symptoms • Swelling, deformity, pain, tenderness, and discoloration • Treatment • Bones must sometimes be put back in proper position (i.e., reduction) • Immobilization through use of a cast • Surgery

6. Muscles • Principal types of muscles: • Skeletal • Under voluntary control • Smooth • Involuntary • Cardiac • Only found in the heart • Involuntary

7. Characteristics of Muscles • Four common characteristics: • Contractibility • Excitability • Extensibility • Elasticity

8. Muscle Attachments and Functions • More than 600 muscles in the body • Muscles attached to bones by tendons • Bones are connected at joints • Muscles are attached at both ends to bones, cartilage, ligaments, tendons, skin, or other muscles

9. Muscle Attachments and Functions (cont’d.) • Origin: part of a skeletal muscle that is attached to a fixed structure or bone • Insertion: attached to a movable part • Belly: central body of the muscle • Prime mover: movement in a single direction • Antagonist: movement in the opposite direction

10. Sources of Energy and Heat • When muscles work, they move the body and produce heat • For muscles to contract and work, they need energy • Major source of energy is adenosine triphosphate • Cell requires oxygen, glucose, and other materials • When a muscle is stimulated, ATP is broken down, producing energy

11. Contraction of Skeletal Muscle • Muscle movement occurs as a result of: • Myoneural stimulation • Contraction of muscle proteins • Skeletal muscles must be stimulated by nerve impulses to contract • Begins with action potential, which travels along muscle fiber length • Basic source of energy is glucose

12. Muscle Fatigue • Caused by accumulation of lactic acid in muscles • During vigorous exercise, blood is unable to transport enough oxygen for complete oxidation of glucose in the muscles • Causes muscles to contract anaerobically (without oxygen)

13. Muscle Tone • Muscles should always be slightly contracted and ready to pull (muscle tone) • Muscle atrophy: • Wasting or loss of muscle tissue resulting from disease or lack of use • Hypertrophy: • Increase in the mass (size) of a muscle

14. Injuries to Muscles • Strain: • Caused by twisting or pulling a muscle or tendon • Acute or chronic • Symptoms: pain, muscle spasm, and muscle weakness • Treatment: reduce swelling, anti-inflammatory drugs, surgery, rehabilitation

15. Injuries to Muscles (cont’d.) • Sprain: • Caused by sudden twist, or a blow to the body • Symptoms: pain, swelling, bruising, and loss of ability to move • Treatment is similar to care for a strain • Tendonitis: • Inflammation of the tendon • Symptoms: pain and inflammation along a tendon • Treatment: avoid aggravating movements, medications, rehabilitation

16. Injuries to Muscles (cont’d.) • Bursitis • Inflammation of a bursa • Symptoms: joint pain often mistaken for arthritis • Treatment: avoid aggravating movements, medications, rehabilitation

17. Injuries to Muscles (cont’d.) • Contusion: • Direct blow that does not break the skin • Symptoms: swelling, pain to the touch, redness, and ecchymosis • Treatment: monitoring, ice, medications, compressive dressing

18. Nerves • Nerve tissue consists of: • Neuroglia • Insulate, support, and protect neurons • Neurons • Sensory • Motor • Associative

19. Nerves (cont’d.) • Nerves carry impulses by creating electric charges through membrane excitability • A synapse is the space between adjacent neurons through the impulse is transmitted

20. Injury to Nerves • Nerves are fragile and can be damaged by pressure, stretching, or cutting • Injury to a nerve can stop signals to and from the brain • Causes muscles to become unresponsive and a loss of feeling in the injured area

21. Soft-Tissue Injuries • Classified as: • Open • Abrasions, lacerations, avulsions, and puncture wounds • Closed • Contusions, hematomas, ecchymoses, sprains, strains, tendonitis, bursitis, and stress-related injuries

22. The Body’s Response to Injury • Inflammation: • Reaction to invasion by an infectious agent or physical, chemical, or traumatic damage • Regeneration: • Act of wound healing • Cellular dedifferentiation: • Regeneration • Cells revert to an earlier stage of development

23. The Body’s Response to Injury (cont’d.) • Transdifferentiation • Regeneration of cells with completely different functions than original • Tissue remodeling • Cells and molecules of tissue are modified and reassembled to yield a new composition of cell types and extracellular matrix

24. Conclusion • The skeleton • Provides support and protection to internal organs • Foundation for muscle attachment • Efficient factory for producing red blood cells • Many injuries associated with athletics are fractures • Other injuries involve muscles, attachments, and various surrounding tissues

25. Tissue Response to Injury

26. Inflammatory Response • Acute Inflammation • Short onset and duration • Change in hemodynamics, production of exudate, granular leukocytes • Chronic Inflammation • Long onset and duration • Presence of non-granular leukocytes and extensive scar tissue

27. Cardinal Signs of Inflammation • Rubor (redness) • Tumor (swelling) • Color (heat) • Dolor (pain) • Functio laesa (loss of function)

28. Phases of the Inflammatory Response (3 separate phases) • 1. Inflammatory response phase • 2. Fibroblastic repair phase • 3. Maturation and remodeling phase

29. Phase I • Healing begins immediately • Injury results in altered metabolism and liberation of various materials • Initial reaction by leukocytes and phagocytic cells • Goal • Protect • Localize • Decrease injurious agents • Prepare for healing and repair

30. First hour • Vasoconstriction(15 min)- local anemia and coagulation occur to seal blood vessels and chemical mediators are released • Immediately followed by vasodilation(hyperemia: doesn’t last long) or blood vessel • Second hour • Vasodilation decreases • Blood flow slows • increased blood viscosity(thickness) resulting in edema (swelling that last 24 to ) • Chemical Mediators released

31. 2nd Hr. Chemical mediators • Released to alter membrane permeability, dilatory responses, margination, and phagocytic activity • Histamine- vasodilation and permeability • Leukotrienes- margination • Cytokines- regulate Leukocyte traffic and attract phagocytes

32. Second hour (continued) • Exudate increases: high concentration of RBC’s and protein rich fluid due to increased vessel permeability. (amount depends on damage) • Permeability changes generally occur in capillary and venules • Margination occurs causing leukocytes to fill the area and line endothelial walls • Through diapedesis(passage of blood cells) and chemotaxis(cell movement) leukocytes move to injured area

33. Clot Formation • Platelets adhere to exposed collagen leading to formation of plug (clot) • Clots obstruct lymphatic fluid drainage and aid in localizing injury • Requires conversion of fibrinogen to fibrin • Initial stage: thromboplastin is formed • Second stage: Prothrombin is converted to thrombin due to interaction with thromboplastin • Third stage: thrombin changes from soluble fibrinogen to insoluble fibrin coagulating into a network localizing the injury

35. Chronic Inflammation • Occurs when acute inflammatory response does not eliminate injuring agent • Tissue not restored to normal physiologic state • Involves replacement of leukocytes with macrophages, lymphocytes and plasma cells • Cause for shift from acute to chronic is unknown • Typically associated with overuse, overload, cumulative microtrauma

36. Phase II: Fibroblastic Repair Phase • Scar formation through 3 phases • Resolution (little tissue damage and normal restoration) • Restoration (if resolution is delayed) • Regeneration (replacement of tissue by same tissue) • Referred to as fibroplasia • Complaints of pain and tenderness which gradually subside during this period

38. Scar formation • Formation of delicate connective tissue • With proliferation(rapid increases) of collagen(main structural protein) scar tensile strength(resistance of material breaking down under tension)increases • # of fibroblasts(cells producing collagen) gradually diminishes • Normal sequence = minimal scarring • Persistent inflammation = extended fibroplasia

39. Phase III: Maturation & Remodeling • Long-term process • Realignment of collagen relative to applied tensile forces meaning the begin to look like normal tissues again • Continued breakdown and synthesis of collagen = increased strength • Tissue will gradually assume normal appearance • May require several years to complete

41. Role of Progressive Mobilization • Initially must maintain some immobilization in order to allow for initial healing • As healing moves into repair phase controlled activity should be added • Work towards regaining normal flexibility and strength • Protective bracing should also be incorporated • During remodeling aggressive ROM and strength exercises should be incorporated • Facilitates remodeling and realignment • Must be aware of pain and other clinical signs – may be too much too soon

42. Extent of injury Edema Hemorrhage Poor Vascular Supply Separation of Tissue Muscle Spasm Atrophy Corticosteroids Keloids and Hypertrophic Scars Infection Humidity, Climate, Oxygen Tension Health, Age, and Nutrition Factors That Impede Healing

43. Cartilage Healing • Limited capacity to heal • Little or no direct blood supply • Failure to elicit clot formation and cellular response

44. Ligament Healing • Repair phase will involve random laying down of collagen which, as scar forms, will mature and realign in reaction to joint stresses and strain • Full healing may require 12 months

45. Skeletal Muscle Healing • Initial bleeding followed by proliferation of ground substance and fibroblast • Collagen will mature and orient along lines of tension • Healing could last 6-8 weeks depending on muscle injured

46. Tendon Healing • Big problem • Abundance of collagen is required for good tensile strength • Too much = fibrosis – may interfere with gliding • Initially injured tendon will adhere to surrounding tissues (week 2) • Week 3 – tendon will gradually separate • Tissue not strong enough until weeks 4-5

47. Management Concepts • Drug utilization • Anitprostaglandin agents used to combat inflammation • Non-steroidal anti-inflammatory agents (NSAID’s) • Medications will work to decrease vasodilatation and capillary permeability

48. Management Concepts • Therapeutic Modalities • Thermal agents are utilized • Heat stimulates acute inflammation (but works as a depressant in chronic conditions) • Cold is utilized as an inhibitor • Electrical modalities • Treatment of inflammation • Ultrasound, microwave, electrical stimulation (includes transcutaneous electrical muscle stimulation and electrical muscle stimulation)

49. Therapeutic Exercise • Major aim involves pain free movement, full strength, power, and full extensibility of associated muscles • Immobilization, while sometimes necessary, can have a negative impact on an injury • Adverse biochemical changes can occur in collagen • Early mobilization (that is controlled) may enhance healing

50. Bone Healing • Less complex process • Acute fx have 5 stages • Hematoma formation • Cellular proliferation • Callus formation • Ossification • Remodeling