EXSS265 LCB

Strain

• Deformation of tissue

Stress

• Load placed on tissue

Personal trainer stretches their hamstring with 5lbs of pressure and the hamstring stretches 1 inch

• What is the strain on the hamstring

• What is the stress on the hamstring

• Strain: Stretched 1 inch

• Stress: 5lbs of pressure

What is the yield point:

• Point on stress-strain curve where elasticity ends, marking permanent plastic deformity

If a ligament is strained past the yield point, will it return to its original length?

No

• After tissue stretches past the yield, it ends the plastic zone

• In the plastic zone, tissue no longer returns to original length

What happens to a muscle if it is stretched in the

1. Elastic Zone

2. Plastic Zone

1. Elastic zone
   When stress is removed, muscle returns to normal length

2. Plastic zone
   Muscle is permanently deformed

5 Different Mechanical Forces

1. Compression

2. Tension/Tensile

3. Shear

4. Bending

5. Torsion

Compressive Mechanical Force

• Squeezes or crushes an object by pushing opposing forces inward

  • ie. Ramming into the side of a quad, spinal fractures, acute bone fractues, spinal loading

Tension/Tensile Mechanical Force

• Tissue pulled too hard in opposite directions

  • ie. Hamstring strain or tear from running, spring, jumping

Shear Mechanical Force

• Unaligned, parallel forces push internal tissues or bones in opposite directions causing parts of a structure to slide past one another

  • ie. Implanting a foot that cuts or twists violently and causes the tibia to slide forcefully across the femur

Bending Mechanical injury

• Combined compression on one side of an object and tension on the opposite side, causing it to curve

• One side pushing in while the other pulls out and lets the pressure drill through both

• Asymmetrical load, dual stress

Torsion Mechanical Injury

• Twisting force applied rotationally around an axis

  • ACL Tear, rotator cuff strain, humeral stress adaptation

• Mechanical Force: Tension

• Stress: Load placed on tissue (ie. body weight)

• Strain: Deformation of tissue (ie. tendon strained to tissue failure)

Compression

Five Signs and Symptoms that indicate the injury is in the inflammation phase

When these signs and symptoms begin to resolve, what phase are they entering?

1. Pain

2. Swelling

3. Redness

4. Warmth

5. Loss of function
   
   

Proliferation/Fibroblastic Repair

What are the two main goals of the inflammatory response and the key chemical mediators?

1. Increase blood flow and signal more flow
   Histamine
   → Increase vasodilation and cell permeability
   
   

2. Wall off and clean up
   Leukotaxin
   → Causes margination
   → Leukocytes and platelets bind to fibrin to form fibrin clot
   Necrosin
   → Leukocytes and necrosin clean up debris and fight infection

The 3 phases of healing and how long each of them lasts

1. Inflammatory Response
   0-5 Days

2. Proliferation/Fibroblastic Repair
   3-5 Days — 6-8 Weeks

3. Maturation(Remodeling)
   6-8 Weeks — 6 Months-2 Years

What are the three goals of the Fibroblastic Repair phase?

• Increase vascularization

• Granulation tissue formation

• Extracellular matrix of collagen, elastin, and ground substance

How does the maturation phase make the scar stronger?

• Realigning Collagen Fibers

  • During fibroblastic repair, collagen and elastin are laid in random fashion

  • During maturation phase, collagen and fibers re-align along the lines of stress and strain to make the scar stronger

Read the clinic note below and determine the athletes phase of healing:

S: Junior MSOC athl c/o R anti Tibial pn. MOI: Kicked/tackled inf to shin guard at px a week ago. Denies neurological symptoms. Denies hearing a pop/crack. Pn at rest has decreased from 7/10 to a 1/10. pn while walking has decreased from 8/10 to a 3/10. Pn while running has decreased from 10/10 to a 5/10.
O: 1 week post inj, athl displayed reduce edema (sewlling) along the tibial crest (-) bump test, (-) compression test. AROM in DF/PF limited secondary to pn. MMT DF 5/5,
A: Probably moderate-severe R tibial contusion
P: Progress activity as tolerated per pn response.

• Prolifration/Fibroblastic repair phase

  • Reduced pain and swelling indicated moving out of the inflammatory response

  • One week since injury indicates phase 2 of healing

What are the objectives of SOAP and HOPS?

• SOAP
  Lists the process of an evaluation
  
  

• Hops
  Are the components of an evaluation
  
  Soap creates the overall categories that HOPS fit into

Put each component of HOPS into the right category of SOAP, and describe what a practitioner is looking for in each.

• Subjective

  • History - Get the patients history

• Objective

  • Observation - Do you see swelling or antalgic gait

  • Palpation - Do you feel warmth, swelling, crepitus, deformity, TTP (Tenderness to Palpation) - MMT, AROM, PROM, Anterior Drawer Test (ACL Tear or Knee instability)

  • Special Tests

• Assessment - Diagnosis & Problem list priorities

• Plan - Next steps and treatment/management

What muscle action is occurring when:

1. Athlete does plank:

2. Athlete at the gym performs RDL, lengthening their hamstrings

3. Athlete performs bicep curl:

1. Athlete does plank:
   Isometric
   
   

2. Athlete at the gym performs RDL, lengthening their hamstrings
   Eccentric
   
   

3. Athlete performs bicep curl:
   Concentric

Recall and Describe the 3 different muscle actions

1. Concentric
   Muscle shortens while creating force to overcome a resistance
   Ie. Lifting weight upward during bicep curl
   
   

2. Eccentric
   Muscle lengthens while under a load of controlling a resistance
   Ie. Slowly lowering the weight back down during a bicep curl
   
   

3. Isometric
   Muscle creates tension without changing length of causing joint movement
   ie. Holding a plank or pushing against a solid wall
   
   

4. Bonus: Isokinetic
   Muscle contracts at a constant fixed speed, regardless of applied force
   ie. Using special rehab equipment like a biodex machine

Read note and determine potential injury:

A 20-year-old female lacrosse midfielder reports sudden pn in the posterior left thigh during a transition drill at practice. She reports accelerating to chase an opposing player when she felt a sudden “pull” in the back of her thigh. She immediately slowed down and was unable to continue sprinting. She rates pain as a 5/10 at rest and 8/10 when attempting to run. Walking is uncomfortable but possible. She denies hearing or feeling a pop and denied numbness or tingling. No previous injury to the left thigh. MMT 4/5. Upon palpation you feel a divot in her left hamstring.

Grade 2 (Partial Tear) of their hamstring

• Divot in muscle with 4/5 MMT

Recall and Categorize Different Injury Grades

• Grade 1: Mild, Minor Stretching or Microscopic Tearing of tissue fibers with Slight swelling and normal joint stability

• Grade 2: Moderate, Partial tearing of tissue, Moderate bruising an noticeable pain and some loss of function or stability

• Grade 3: Severe: Complete rupture/Full tear of tissue, severe pain, significant swelling, and major loss of function and complete joint instability