Understanding and Managing
Healing Process through
Rehabilitation
Rehabilitation Techniques for Sports
Medicine and Athletic Training
William E. Prentice
Introduction

Rehabilitation requires sound knowledge
and understanding of tissue healing process
 Athletic Trainer designs, implements and
supervises rehab programs
 Rehab protocols and progressions must be
based on physiologic responses of tissues to
injury and understanding of how various
tissues heal
Introduction

Primary Injury
– Injury from acute or chronic trauma

Secondary Injury
– Inflammatory response to primary injury
3 Phases of Tissue Healing

Inflammatory –response phase

Fibroblastic-repair phase

Maturation-remodeling phase
– Healing process is a continuum and phases
overlap one another with no definitive
beginning or end points
Inflammatory-Response
Phase

After injury, healing process begins
immediately
– Destruction of tissue produces direct injury to
cells of various soft tissue
– Characterized by redness, swelling, tenderness
and increased temperature
– Critical to entire healing process
Inflammatory-Response
Phase

Leukocytes and other phagocytic cells
delivered to injured tissue
– Dispose of injury by-products through
phagocytosis
Inflammatory-Response
Phase

Vascular reaction

Chemical mediators
– Blood coagulation and
– Released from damaged
growth of fibrous
tissue occurs
– First 5-10 minutes
vasoconstriction occurs
 Best time to
evaluate
 Followed by
vasodilation
 Effusion of blood
and plasma last 24
to 36 hours
tissue, white blood cells
and plasma
– Histamine, leukotrienes
and cytokines assist in
limiting exudate/swelling
– Amt of swelling directly
related to extent of vessel
damage
Inflammatory Response Con’t

Formation of Clot
– Platelets adhere to
collagen fibers and create
sticky matrix
 Platelets and
leukocytes adhere to
matrix to form plug
 Clot formation occurs
12 hours after injury
and is complete w/in
48 hrs
 Set stage for
fibroblastic phase

Chronic inflammation
– Acute phase does not
respond sufficiently to
eliminate injury agent
and restore tissue to
normal physiologic state
– Damage occurs to
connective tissue and
prolongs healing and
repair process
– Response to overuse and
overload
Inflammatory Response Con’t

Entire phase last 2-4 days
– Greater tissue damage longer inflammatory phase
– NSAIDS may inhibit inflammatory response thus
delaying healing process

Will assist with pain and swelling
Fibroblastic-Repair Phase

Proliferative and regenerative activity leads
to scar formation
– Begins w/in 1st few hours after injury and can
last as long as 4-6 weeks
– Signs and Symptoms of inflammatory phase
subside
– Increased O2 and blood flow deliver nutrients
essential for tissue regeneration
Fibroblastic-Repair Phase

Break down of fibrin clot forms connective
tissue called granulation tissue
– Consist of fibroblast, collagen and capillaries
 Fills gap during healing process
– Unorganized tissue/fibers form scar

Fibroblast synthesize extracellular matrix consisting
of protein fibers (Collagen and Elastin)
– Day 6 –7 collagen fibers are formed throughout scar
– Increase in tensile strength increases with rate of collagen
synthesis
Fibroblastic-Repair Phase

Importance of Collagen
– Major structural protein that forms strong,
flexible inelastic structure
– Type I, II & III


Type I found more in fibroblastic repair phase
Holds connective tissue together and enables tissue
to resist mechanical forces and deformation
– Direction of orientation of collagen fibers is along lines of
tensile strength
Fibroblastic-Repair Phase

Importance of Collagen
– Mechanical properties
 Elasticity
– Capability to recover normal length after elongation

Viscoelasticity
– Allows slow return to normal length and shape after
deformation

Plasticity
– Allows permanent change and deformation
Maturation-Remodeling Phase

Long term process that involves realignment of
collagen fibers that make up scar
– Increased stress and strain causes collagen fibers to
realign to position of maximum efficiency
 Parallel to lines of tension
 Gradually assumes normal appearance and function
 Usually after 3 weeks a firm, contracted,
nonvascular scar exist
– Total maturation phase may take years to be
totally complete
Maturation-Remodeling Phase

Wolf’s law/Davies Law
– Bone and soft tissue will respond to physical
demands placed on them


Remodel or realign along lines of tensile force
Critical that injured structures are exposed to
progressively increasing loads throughout rehab
process
– As remodeling phase begins aggressive active range of
motion and strengthening
– Use pain and tissue response as a guide to progression
Maturation-Remodeling Phase

Controlled mobilization vs. immobilization
– Animal studies show Controlled mob. Superior
to Immobilization for scar formation

However, some injuries may require brief period of
immob. During inflammatory phase to facilitate
healing process
Factors that impede healing

Extent of injury

– Bleeding causes same neg.
– Microtears vs.
macrotears

Edema
– Increased pressure
causes separation of
tissue, inhibits neuromuscular control,
impedes nutrition,
neurological changes
Hemorrhage
effect as edema

Poor vascular supply
– Tissues with poor vascular
supply heal at a slower rate
– Failure to deliver
phagocytic cells and
fibroblasts for scar
formation
Factors that impede healing

Separation of tissue

– How tissue is torn will
– In early stages shown
effect healing


Smooth vs. jagged
Traction on torn
tissue, separating 2
ends
– Ischemia from spasm
spasm

Atrophy
Corticosteroids
to inhibit healing

Keloids or
hypertrophic scars
 Infection
 Health, Age and
nutrition
Healing Process-Ligament
Sprains

Tough, relatively inelastic band of tissue
that connects bone to bone
– Stability to joint
– Provide control of one articulating bone to
another during movement
– Provide proprioceptive input or sense of joint
position through mechanoreceptors

3 Grades of lig. tears
Healing Process-Ligament
Sprains

Physiology
– Inflammatory phase-loss of blood from
damaged vessels and attraction of inflammatory
cells
– During next 6 weeks-vascular proliferation with
new capillary growth and fibroblastic activity

Immediately to 72 hours
– If extraarticular bleeding in subcutaneous space
– If intraarticular bleeding occurs in inside joint capsule
Healing Process-Ligament
Sprains

Essential that 2 ends of ligament be reconnected
by bridging of clot
– Collagen fibers initially random woven pattern with
little organization
– Failure to produce enough scar and of ligament to
reconnect 2 reasons ligaments fail

Maturation
– May take 12 months to complete
– Realignment/remodeling in response to stress and
strains placed on it
Healing Process-Ligament Sprains

Factors that effect healing
– Surgery or non surgical approach
Surgery of extraarticular ligaments stronger at first
but may not last over time
 Non surgical will heal through fibrous scarring , but
may also have some instability
– Immobilization
 Long periods of immobilization may decrease
tensile strength weakening of insertion at bone
 Minimize immobilization time
 Surrounding muscle and tendon will provide
stability through strengthening and increased muscle
tension

Healing Process-Cartilage

Cartilage
– Rigid connective tissue that provides support
 Hyaline cartilage: articulating surface of bone
 Fibro cartilage: interverterbral disk and menisci.
Withstands a great deal of pressure
 Elastic cartilage: more flexible than other typesauricle of ear and larynx
Healing Process-Cartilage

Physiology of healing
– Relatively limited healing capacity
 Dependant on damage to cartilage alone or
subchondral bone.
 Articular cartilage fails to elicit clot formation or
cellular response
 Subchondral bone can formulate granulation tissue
and normal collagen can form
Healing Process-Cartilage

Articular cartilage repair
– Patients own cartilage can be harvested and implanted
into damages tissue to help form new cartilage
– Promise for long term results

Fibrocartilage/Menisci
– Depends on where damage occurs
– 3 zones of various vascularity

Greater that blood supply better chance of healing on own
Healing Process-Bone

Similar to soft tissue healing, however
regeneration capabilities somewhat limited
– Bone has additional forces such as torsion, bending and
–
–
–
–
compression not just tensile force
After 1 week fibroblast lay down fibrous collagen
Chondroblast cells lay down fibrocartilage creating
callus
At first soft and firm, but becomes more firm and
rubbery
Osteoblast proliferate and enter the callus

Form cancellous bone and callus crystallizes into bone
Healing Process-Bone

Osteoclasts reabsorb bone fragments and
clean up debris
– Process continues as osteoblast lay down new
bone and osteoclasts remove and break down
new bone


Follow Wolfs law-forces placed on callus-changes
size, shape and structure
Immobilization longer 3 to 8 weeks depending on
the bone
Healing Process-Muscle

Similar to other soft tissue discussed
– Hemorrhage and edema followed by phagocytosis to
clean up debris
– Myoblastic cells from in the area and regenerate new
myofibrils
– Active contraction critical to regaining normal tensile
strength according to Wolff's Law
– Healing time lengthy-Longer than ligament healing


Return to soon will lead to re-injury and become very
problematic
6-8 weeks?
Healing Process-Tendon

Not as vascular as muscle
– Can cause problems in healing
– Fibrous union required to provide extensibility
and flexibility


Abundance of collagen needed to achieve good
tensile strength
Collagen synthesis can become excessive can result
in fibrosis: adhesions from in surrounding structures
– Interfere with gliding and smooth movement
– Tensile strength not sufficient to permit strong pull for 4 to
5 weeks
• At risk of strong contraction pulling tendons ends
apart
Healing Process-Nerve

Nerve cell is specialized and cannot
regenerate once nerve cell dies
– Injured peripheral nerve- nerve fiber can
regenerate if injury does not affect cell body
– Regeneration is very slow 3-4 mm /day


Axon regeneration obstructed by scar formation
Damaged nerve within CNS regenerate poorly
compared to peripheral nervous system
– Lack connective tissue sheath and nerve cells fail to
proliferate
Rehabilitation philosophy

Choose therapeutic exercises/modalities that
facilitate healing process at specific phases
– Stimulate structural function and integrity of injured
part
– Positive influence on the inflammation and repair
process to expedite recovery of function
– Minimize early effects of inflammatory process
including pain, edema control, and reduction of muscle
spasm.

Produce loss of joint motion and contracture
– Finally concentrate on preventing reoccurrence of
injury by assuring structural stability of injured tissue

Appropriate return to play guidelines