Tissue Behavior and Injury Healing (Tendons: Slides 40-53)

Tendons are dense regular connective tissue that...

Produces joint motion

Stores elastic energy that contributes to movement when stretched

Allows for the optimal distance between the muscle belly and the joint it is acting upon

What is the main function of tendons?

To transmit the load from muscle to bone

*designed to resists strong tensile loads but NOT to resist shear or compressive forces

Tendons consist of groups of collagen fibers bound together and are organized into...

Primary, secondary, and tertiary bundles

What are the three major sections of a tendon?

Bone-tendon junction (called the enthesis)

Tendon mid-substance

Musculotendinous junction (MTJ)

The ___ functions to absorb and distribute stress and is therefore vulnerable to injury.

Bone-Tendon junction (enthesis)

The part of tendon between posterior tibial and peroneal arteries that is most common location for achilles tendon ruptures..

Tendon mid-substance

Where a muscle and tendon meet and transmit force between the two tissues...

Musculotendinous junction (MTJ)

*very susceptible to tensile failure

There are more ____ in tendons than ligaments that align with tendon's axis during remodeling phase.

collagen fibers

___ is thought to results from underload or overload to tendon.

Tendinopathy

Tendinopathy

Strain injuries are most common at...

A tendon's ability to resist load and stretch depends on its...

Tendons can get stronger and better at handling loads with...

Musculotendinous junction

Cross-sectional area, composition and length

Regular and proper use

Tendons that transmit large loads under eccentric and elastic conditions such as the achilles and patellar tendons are...

More subject to injury

Tendinitis implies ___ with only 3% of tendon issues thought to be inflammatory.

Inflammation

___ is a more general and appropriate term to describe that 'all is not well in the tendon'

Tendinopathy

Most of the tendon is ____ and does not exhibit classical inflammatory responses therefore...

Aneural and avascular

Tendon symptoms are not consistent with tri-phasic inflammation so we should avoid therapy such as absolute rest, ice and anti-inflammatory meds

Tendinopathy can be persistant and recalcitrant with..

Symptoms occurring for many years

*chronic tendon injury 30% of all RRIs

The source of pain in tendons cannot be seen in..

Tendon imaging because there is an inconsistent relationship between pain and pathological changes identified on imaging

**maybe because pain is from CNS which might not be associated w/ physiological nociceptive caused by tissue disruption

What are some extrinsic factors that increase likelihood of tendinopathy?

Excessive volume, magnitude or speed of muscle contraction

Physical requirements of lifting

Abrupt changes in amount or type of load

Environmental changes (cold or running surface)

___ is most likely to cause tendon damage than the same load applied/removed gradually.

Rapid application/release of force

What are some intrinsic factors increasing likelihood for tendinopathy?

Muscle weakness

Muscle imbalance

Decrease flexibility

Poor form (ergonomics)

Age

Adiposity (increased fat mass)

Tendon injuries can be acute or chronic. Acute injuries are...

Chronic injuries are...

Time and method are unknown and include a tendon rupture or partial tears

No specific incident but typically involve repetitive loading.

*typically accompanied by dense populations of fibroblasts; vascular hyperplasia; disordered collagen

What are considerations for tendon healing?

Poor healing is common (adhesions may develop)

Careful progression of loading

Symptom management

Inflammation treatments will not work

Careful progression of loading during tendon healing ...

Promotes collagen synthesis

Collagen fiber cross-linking

Proper collagen alignment in the direction of force application

Symptom management sees that any worsening edema, morning stiffness or delayed onset pain should be...

monitored/controlled as inflammation could drive the tendon further down the wrong pathological path

Inflammatory infiltrates are largely ___ in tendonopathy therefore...

Absent

Anti-inflammatory strategies are ineffective and instead managment of tendinopathy should involve appropriate loading of the tendon, with therapeutic loads being administered carefully and in a gradual and controlled manner

___ training seems to be beneficial for treating chronic tendinopathy.

Eccentric-based

-warm up, stretching, specific exercises, repeated flexibility exercises

What is the main goal for treating tendinopathy?

Achieve flexible and strong muscles and stiff tendons

*STIFF is good

*Interventions should promote repair and remodeling NOT inflammation

4 treatments for tendinopathy...

1. Isometrics then eccentric strengthening

2. Address entire kinetic chain

3. Platelet-Rich Plasma

4. NASAIDS do NOT benefit long-term