Tendon and Ligament Injury

function of a tendon

stretch and recoil

function of a ligament

stability of joints

type of loading tendons need

tensile

type of loading cartilage needs

compression

optimal area of load-deformation curve for tissue deformation

plastic region (before ultimate failure point)

effect of a longer tendon

it can pull further with the same force and produces longer/smoother movements

effect of tissue thickness on strength

thicker tissue has more strength and stiffness (increased resistance) leading to withstanding more load

stress

force per unit area (tensile load)

strain

elongation per unit length in response to the tensile load (stress)

young’s modulus

a measure of a material’s stiffness (resistance to elastic deformation under stress)

compliance

the opposite of young’s modulus that tells how flexible a material is

viscoelasticity

combination of viscosity and elasticity that tells how the fluid of tissues affect its resistance to load

how do plyometrics work

work on the concept of viscoelasticity where a quick load leads to greater resistance and therefore recoil

creep

force applied remains the same over time and the deformation increases

concept of stress-relaxation

if a tissue is stretched to a fixed length, over time the force required to keep it at that length decreases

hysteresis

loading and unloading does not follow the same path due to energy lost (via heat, etc)

strain-rate sensitivity

the faster the load is applied the stiffer the tissue is

how to decrease the stress and peak loading on a tissue

slower loading

effect of immobilization on tissue stiffness

immobilization decreases the tensile strength and stiffness and leads to contractures

how to reduce the effects of immobilization on tendons/ligaments

immobilize the tissue in an elongated position

why are grade III sprains the least painful

sensory fibers are completely divided

grade I sprain

stretched fibers but minimal to no change in ROM when stressing the ligament

grade II sprain

involves considerable portion of the fibers and stressing the ligaments reveal joint laxity

grade III sprain

complete tear of the ligament with excessive joint laxity and no firm end point

treatment of grade I and II sprains

prevent joint stiffness, protect against further damage, strengthen muscles for joint stability

treatment of grade III sprains

surgery, immobilization/bracing

rationale for bracing ligament injuries

the tissue needs to be directed and told which direction to heal

importance of tendons in sport function

save energy, controls movements, improve explosive performance, return 90-95% of stored energy

how do tendons save energy

rebound/recoil effect

main clinical problem of tendon overuse injuries

pain

main clinical problem of acute tendon injuries

loss of function (bc more likely a complete rupture)

examples of overuse injuries of the achilles tendon

midportion/distal (insertional) tendinopathy, paratendonitis, distal bursitis

risk factors of achilles tendon injuries

collagen fibers that are thinner and looser, increased proteoglycans, increase water

why are chronic tendon injuries no longer referred to as tendinitis

there were no signs of acute inflammation at the site of injury

shift in treatment of tendinopathies

treatment shifted from more inflammation focused (rest, ice, NSAIDs) to more loading and exercise

diagnosis of tendinopathy

based on history of activity provoked localized tendon pain and stiffness

classifications of tendinopathies

tendinosis, tendinitis/partial rupture, paratenonitis, paratenonitis with tendinosis

paratenonitis

inflammation of the sheet around the tendon

pathophysiology of tendinopathy overuse

prolonged abusive training leads to failed tissue adaptation that becomes painful overtime

what occurs during the period of vulnerability to re-injury

pain has recovered by strength has not so there is a false sense of reassurance when returning to sport

stages of tendon healing

inflammatory phase: a few days, repair phase: around a month, remodeling phase: around a year

function of the inflammatory phase in tendon healing

start healing process and clean up the area

function of the repair phase in tendon healing

temporary quick fix

cause of tendon overuse injury

training errors like insufficient recovery

function of the domains of tendon health

help guide how you treat the injury (treat problems not symptoms)

clinical presentation of tendon overuse injury

activity provoked pain, pain on palpation, feeling of stiffness, pain alleviated with rest, altered tendon structure

characteristics of tendon metabolism

active but slow, balance between collagen synthesis and degradation, allows carrying of loads and maintenance of tension

osteotendinous junction

where the tendon progressively turns into bone

cause of gluteal tendinopathy

compression of tendon (adduction)

compression of the achilles tendon

dorsiflexion causes compression at the insertion

function of hopping as a clinical test

evaluating movement quality and symptoms with loading the achilles tendon

highest level of evidence treatment for achilles tendon

exercise/loading

age effect on tendon

has effects similar to disuse that can be counteracted by exercise

tendon response to mechanical stimulus

strain

how to increase stiffness and size of achilles tendon

low load for long duration

benefit of eccentric loading even though there is no difference to the tendon

you are able to apply a greater load than concentric exercise

benefit of isometric loading

gives you the ability to load a tendon that is painful

components of total muscle tension/force

passive (elastic component) and active (contractile components)

parameters affecting loading (stress/strain) on the tendon

total amount of load, speed, length of time

why do we want to avoid high peak load of tendons

risk of re-reupture

optimal peak tendon load

50% of body weight

optimal cumulative loading applied to the tendon (loading impulse)

30% of body weight

optimal loading rate of tendon

20% change

movements of increasing achilles tendon loading

slow multi-joint → dynamic single leg

achilles pain affect on motor response

decreased activity in agonistic, synergistic, and antagonistic muscles

components of achilles rehab program

progressive loading, dosing with pain-monitoring model

phases of achilles tendon strengthening program

symptom management → recovery → rebuilding → return to sport

pt status at phase 1 of achilles tendon rehab program

pain and difficulty with activity, difficulty performing 10 SL heel rises

goal of phase 1 of achilles tendon rehab program

start exercise, understand how to use the pain-monitoring model, progress to 100% BW

pt status at phase 2 of achilles tendon rehab program

pain with exercise, but less than 2-3 with ADLs, morning stiffness

goal of phase 2 of achilles tendon rehab program

strengthen tendon and muscle, progress load and speed

pt status at phase 3 of achilles tendon rehab program

doing well and desire to progress to heavier activities

goal of phase 3 of achilles tendon rehab program

start running, jumping, and plyometrics

pt status at phase 4 of achilles tendon rehab program

minimal symptoms, no morning stiffness

goal of phase 4 of achilles tendon rehab program

maintenance and tendon strengthening, sport-specific loading and movements

clinical presentation of tendon rupture

strong muscle contraction while the tendon is forcefully extended, loud pop, immediate loss of function, pain subsides quickly

achilles tendon rupture healing pathologies

heal with a callus, thicker, longer

why should stretching be avoided when the tendon is healing

it already heals longer so it can result in active insufficiency

consequence of elongated achilles tendon

decreased PF