Chapter 1- Tissue Response to Injury PDF

Preview

Summary

Prevention and Care of Sport Injuries with professor Davis....

Description

Tissue Response to injury ● The healing process ○ Essential to possess in depth knowledge of healing process ■ Understand phases ■ Time frames physiological changes associated with each phase ○ Must create a conducive environment for healing ○ Healing is a continuum ● Phases of the inflammatory response ○ 1. Inflammatory response phase ■ Red,swollen, warm, tender pain ■ Healing begins immediately ■ Injury results in altered metabolism and liberation of various materials (prepare for healing and repair) ■ Chemical reaction ● Body releases 3 main chemicals ○ Histamine ■ Released from injured mast cells ■ Vasodilation ■ Increased permeability for swelling ○ leukotrienes/prostaglandins ■ Responsible for margination (process in which leukocyte adhere along the cell walls) affect passage of fluid, proteins and neutrophils and allow inflammation ○ Cytokines ■ Help attract phagocytes to the site of inflammation and regulate leukocyte traffic ■ Macrophages and neutrophils respond to the presence of cytokines ■ Neutrophils:peak at 6 hours ■ Macrophages between 12-24 hours ● Chemicals promote vasodilation which allows an increase in blood flow and cell permeability

●

●

●

● ●

(swelling) ■ Vascular reaction upon injury ● Initially blood vessels constrict for 5-10 mins ● Next blood vessels dilate allowing blood flow ● Blood flow gradually slows down (24-36 hours) Formation of platelets ○ Also adhere to the vascular cell wall at site of damage ○ Adhere to exposed collagen fibers creating a sticky matrix Clotting ○ Clot formation begins around 12 hours and completed within 48 hours ○ Sticky fibrin forms through a series of events ○ Shuts off blood supply Chronic inflammation ○ Normal inflammatory phase lasts 2-4 days ○ Caused by repeated microtraumas ■ Injured tissues can’t heal ■ Connective tissue is damaged Treatment goals ○ Rest, ice, compression, elevation Phase 2: Fibroblastic repair phase ○ Less swollen, less painful, bruising, regain function ○ Scar formation (Fibroplasia) and tissue repair ■ Not necessarily a visual scar but also new tissue being laid down ■ Begins in first few days of injury ■ Tenderness with touch ○ Endothelial capillary buds form in the wound (lack of O2) ■ Wounds heal aerobically ■ Oxygen and blood flow increases, promotes healing ■ Nutrients essential for tissue regeneration are delivered ○ Granulation tissue fills gaps during healing ■ Fibroblasts (increased with blood blow) , collagen (forms scar tissue), capillaries ■ Laid out randomly

■ Reddish, granular mass of connective tissue ○ Can take up to 6 weeks, pain subsides during this phase ○ After 5 days, switch from ice to heat and work on range of motion ○ Treatment goal ■ Prevent excessive muscle atrophy and joint deterioration in injured area ■ Balance between low load stress is introduced ● Phase 3: maturation and remodeling ○ Long- term ○ Realignment of collagen relative to applied tensile forces ○ Continued breakdown and synthesis of collagen=increased strength ○ Tissue will gradually assume normal appearance ○ 2-4 months of years to complete ○ Wolff's law ■ Bone and soft tissue respond to physical demand placed on them ○ Appearance and treatment ■ Body part will appear normal ■ Progressive strength training ■ May fatigue faster ■ Gradual return to sport ■ Treatment goal ● Optimize tissue function by progressing the activities performed during phase by adding advanced sport specific exercises ■ Role of progressive mobilization ● Must maintain some immobilization in order to allow initial healing ● Controlled activity should be added ○ Regain flexibility and strength ○ Braces should be worn ● Aggressive range of motion and strength exercises should be incorporated

○ Remodeling and realignment ● Objectives in place by therapists that allow for step progression ○ Joint angle specific strengthening ○ Transition from general to sport exercises ○ Movement speed ○ Velocity-specificity strengthening exercises (velocity must progres to those used on athletes sport) ○ Neuromuscular control (technique!) ○ Open and closed kinetic chain exercises ● Factors that impede healing ○ Severity of injury ■ microtears/macrotears ○ bleeding/edema causes separation of tissues and slows healing (ligament tear and no connection of fibers) ○ No blood supply ■ No blood=no nutrients ○ Muscle spasm ■ Causes traction (pulling) in tissues ○ Atrophy ○ Infection ○ age/health/nutrition...