Lecture 5 - Tissue Pathophysiology & Healing Flashcards
define an injury
- disruption of the continuity and/or function of tissue in the body
individual/intrinsic injury risk factors
- strength
- fitness
- body comp
- age
- injury history
- playing level
external/extrinsic risk factors
Human Factors
- team mates, opponents
Protective equipment
- helmets, shin guards
Sports Equipement
- skis
Environment
- weather
- floor/turf
- temperature
foundational concept of how does a tissue injury occur
the load exerted on the tissue exceeds the tissue capacity
main structures of a tendon
- collagen microfibres and tropocollagen (type 1)
- endotendon
- epitendon
SEE SLIDE 8
types of tendon injuries
- tendinopathy (tendonitis; don’t really say this anymore)
- tendon rupture
type 1 vs type 3 collagen role in tendon healing
- type 3 is placed down half hazardly (not in same direction as muscle fibres, messy) which has more of an elastic component. type 3 is short term, not good tissue
- type 1 then comes in for a real fix; type 1 is the base unit of tendons and is designed to deal with tensile load in tendons, muscles, and ligaments
list and explain the main stages of tendon healing
- inflammatory stage (up to 7 days)
- phagocytosis of necrotic tissues (clears he way)
- increase of vascular permeability, initiation of angiogenesis and tenocyte proliferation (increase) - remodelling stage (1 - 6wks)
- peak of type 3 collagen, will continue for a few more weeks - Modeling Stage (6+ wks)
3a. Consolidation (6-10 wks)
- change from cellular to fibrous collagen, collagen is aligned in the direction of the stress
3b. Maturation (10+weeks)
- continues to remodel the tissue
list all parts of the muscle
see slide 11
muscle injuries are most common in which muscles
10-55% of athletic injures are muscle injuries
- hamstrings
- adductors
- quadriceps
- calf muscles
types of muscle injuries
- contusions
- sTrains (grade 1 - 3)
- lacerations
explain different muscle strains
Grade 1
- strain usually causes stretching of a few muscle fibres
Grade 2
- more significant damage, more muscle fibres are torn or damaged (less than 50% of muscle)
Grade 3
- a complete (50%> or more) tear/rupture of the muscle
Different phases of muscle healing
- Destruction Phase
- muscle injury > formation of hematoma > inflammatory response - Repair Phase
- phagocytosis of necrotic tissues
- myogenic reserve cells (satellite cells) are activated and become myoblasts, then myoblasts fuse to myotubes
- 5-6 days after the injury the myotube attach both ends of the stump - Remodeling Phase
- formation of contractile
- fibroblasts become myofibroblasts which have contractile capabilities
- scar is formed and becomes stronger over time
types of ligament injuries
sPrains
Grade 1
- minimal to moderate pain, minimal to swelling, strength or ROM deficit
Grade 2
- a lot of pain, moderate decreased strength and ROM, moderate swelling
Grade 3
- maybe a lot of pain or none, severe decrease in strength and ROM, severe swelling
phases of ligaments healing
- inflammatory phase
- ligament tear
- hematoma
- phagocytosis - Repair Phase
- fibroblasts creates type 3 collagen and continues for a week
- increase in glycoaminoglycans > increased water and ligament swelling - Remodelling phase
- formation of a scar
- type 1 collagen replaces type 3
approximate tissue healing time lines
Muscle - 2 to 6 wks
Tendon - 2 to 6wks acute, 8-12 months chronic
Ligament - 3to12 months (T has 1/10th the BF as muscles)
Bone - 6-18wks
rehab prinicples
- restoring function
- increasing ROM
- increasing muscle strength
- increasing sport endurance
INCREASE CAPACITY
what is the sequential and progressive multi-phase approach you should follow with injury rehab
Phase 1 - acute management/inflammation control
Phase 2 - restoring strength and ROM
Phase 3 - advanced strengthening
Phase 4 - functional/sport specific/return to play
what do you do in Phase 1 of injury rehab
Acute Inflammation Stage
- immobilization for the first 3-6 days depending on the severity
- minimize effects of immobilization
- control pain, inflammation and bleeding (RICE, NSAIDS, etc)
- mobilization within pain, want to avoid re-rupture/tear
- isometric contractions after 3-6 days
MAIN GOAL: minimize damage done by the injury and inflammation
Ice or Heat
ICE
- pain relief when on and continues when removed
- reduces inflammation and edema
- decreases tissue metabolism
Heat
- heat can penetrate deeper muscles but pain relief stops when heat is removed
- increase metabolic activity
- reduction of spasm
- facilitation of tissue healing
best way to apply ice
10 mins ON - 10 mins OFF - 10 mins ON
*so you body doesn’t think it’s getting hypothermic and send more blood to cold area
isometric training in rehab
- heavy isometrics have show to decrease pain immediately and lasted for 45 minutes (patellar tendon)
- used early in the management to build capacity and it’s important to stay in the limits of the plan
- best to be used in early phase post injury
WHY - fibroblasts (tenocytes, myofibroblasts, etc) respond to tensile stimulus; they will produce collagen after being stimulated
what is mechanotransduction
Mechanotransduction describes the ability of a cell to actively sense, integrate, and convert mechanical stimuli into biochemical signals that result in intracellular changes, such as ion concentrations, activation of signaling pathways and transcriptional regulation (1)
mechanotherapy
the employment of mechanotransduction for stimulation of tissue repair and modelling
- mechanical loading stimulates protein synthesis at the cellular level, leading to tissue remodelling
steps of mechanotransduction
Mechanotransduction is a multistep process that includes
(1) mechanocoupling (transduction of mechanical forces into signals sensed by sensor cells)
(2) biochemical coupling (conversion of mechanical signal into a biochemical signal to elicit a cellular response such as gene activation) Ca2+ and IP3
(3) transfer of a signal from sensor to effector cells, and
(4) the effector cell response (protein synthesis)
What do you do in Phase 2 of injury rehab
Intermediate phase
- isometric, concentric, eccentric exercises to increase tissue strength
- stretching and mobilization to increase ROM
- ensure to train the range that the tissue was injured in to make it stronger, decreasing the likelihood of future injury
- heavy resistance training and plyometrics can be added at the later point in this stage as you move closer to stage 3
MAIN GOAL: increase strength and ROM
what do you do in phase 3 of injury rehab
Advanced Strengthening
- must be pain free, have full ROM, no tenderness with palpation, and at least 70% strength of the unaffected side
- begin adding more load to increase the capacity of the area
MAIN GOAL: increase the strength of the tissues
what do you do in phase 4 of injury rehab
Return to play
- begin with short-specific training prior to match play
- 90%+ strength as well as be able to perform the required tasks in order to return to play
MAIN GOAL: return to play
What happens if the relationship between load and capacity is unbalanced
Load > Capacity = injury
Load =< Capacity = Rehab
Load < < Capacity = Injury prevention
Different types of exercises and their effects on injury prevention
- Stretching showed least impact
- Strength training showed the greatest impact
- Proprioception was second most impactful
- Multiple exposures was slightly below proprioception
exercise in general decreased the amount of injuries
why…..
increase tissue strength = increase capacity = decreased likelihood of injury
