Knee Injuries Flashcards
How might contact/non-contact activites show up in knee injuries?
- majority of knee injuries are non-contact mechanisms
- contact injuries have some non-preventable “unlucky” events
Which is more common in knee injuries: hyperflexion or extension?
hyperextension
How does hyperextension/flexion impact the knee ligaments?
*unclear from slides - hyperextension prob affects most except pcl, hyperflexion would cause pcl injury
hyperextension might cause PCL injury
- hyperflexion might affect menisci
What happens with valgus collapse?
- MCL can pop first, ACL is next
How does the trunk affect knee injuries?
- trunk is part of the story! Knees don’t only just collapse in a direction on their own. This is why core work is very important
How might foot and ankle positioning/disrupted function affect knee injury risk?
- ppl who land flat footet/without a toe to heel drop can affect the knee
- when we land from a jump, ankle is supposed to absorb some of that impact
- if you cut the ankle from the picture, knee is next in line
- if we are retraining someone after an ACL injury, we would focus on ways to strengthen so this doesn’t happen again
How can information given on sense of collapse or rupture like hearing a “sound” helps us identify injury?
- often patient will tell you if they felt something shift or if a noise was made
- quick changes in direction can give chance of failure
- sometimes “gave out and buckled” is used, could indicate torn meniscus too
If the swelling had a slow build, what does this tell us about the injury?
- Synovial fluid slowly builds up which can take up to 24 hours = slow build probably means joint effusion
- we have synovial fluid in joint for fluid movement but in injury this fluid is overproduced.
If swelling occurs within an hour, what does this mean?
this is swelling from a bleed = we have damaged something that has blood supply
What does weight bearing status tell us about knee injuries
not much, weight bearing is too variable to be meaningful
OK ON SURFACE DOES NOT MEAN OK
Is there a colour indication of bleed-related swelling?
no - unless you damage the capsule the bleeding is on the inside
can you damage the MCL with no joint effusion?
yes
What might localized swelling mean?
- might mean damage of that specific structure
What may happen to the knee appearance with joint effusion?
lose contour of the knee
Deformities should be watched out for: how might this present in a patella?
patellas will typically dislocate laterally (sometimes snaps back in when quads contract)
REVIEW: what are the lateral knee structures?
- LCL between femur and fibula
- meniscus sandwiched in between
- Lateral patellofemoral ligament connects patella
REVIEW: what are the medial knee structures
- MCL between femur and tibia (wider than LCL)
- medial meniscus sandwiched
- medial patellofemoral ligament (usually damaged more often in patellar dislocation since lateral dislocation is more common)
REVIEW: what does the ACL limit?
- anterior translation of tibia
- twisting tibia in any direction will put stress on ACL (happens when ppl plant foot and pivot)
more extension = more stress on ACL
REVIEW: what does the PCL limit?
- posterior translation of tibia
- more flexion = more stress on PCL
Are ACL injuries the majority?
no, we just hear more about them
What is the incidence of ACL injuries between females/males
1/29 female athletes
1/50 male athletes
- lots of factors involved (neural etc.)
- relative risk this happens to women is 1.5 men’s risk (50% higher)
How does family history affect ACL injury statistically?
- ppl who have parent/sibling with ACL injury have 2.53x more risk than someone who is not related to anyone who tore ACL
Do all ACL injuries need surgery?
- if you have a minor ACL injuri you can still play a lot of the time, depends on neuromuscular status before and degree of rupture
- if you’re an athlete and need ot do all sorts of pivorting you will probably get surgery
- you could get lucky and have some minor tearing and some healing over time if you take it easy
What is the primary source of chronic knee pain?
patella
What 2 conditions are included under the title of “anterior knee pain?”
- patellar tendinopathy
- patellofemoral pain syndrome
What might aggravate patellar injuries/anterior knee pain?
- any activity that requires person to actively extend their knee or absorb impact
- some things are more aggravating than others (ex. stair running)
What sound/sensation may be associated with anterior knee pain?
- grating sound (crepitus), feels like not everything in joint is gliding smoothly
- affected articulation
If a knee is “unstable”, is this always cause for concern?
- no, one of the components of patellar issues is weakness of quadriceps
- part of this means when we have pain in knee and reflex it inhibits quadriceps from working
- collapse can be a moment in time when quads forgot to do their job and support you (contract against gravity) and you get buckling of the knee
What is the pain distribution for patellar injuries?
- margin of patella
- lateral side
- deep under patella = patellar syndrome
What mechanically explains why we get more lateral patellar injuries?
- 1 continuous knee extensor mechanism
- look at line of pull! Quads follow femur up and laterally
- if we took the vectore and broke into vertical and horizontal components we get a force at an angle
- quads pull to LATERAL side and up
What is the mechanical issue behind patellofemoral pain syndrome?
compression and shear beyond tolerance
What are the possible explanations of PFPS?
- patellar mal-alignment
- overload: training exceeding capacity
Why might there be a metabolic issue for tendons? (from tendinopathy concepts)
tendons are energy absorbers, eccentric focus
- tendon heals veryyy slowly
- metabolically slow healing tissue
- has blood supply but not a lot, slower healing
what is the occurence of patellar tendinopathy in athletes and possible risk factors for the general population?
- 18% of athletes, greater risk in court sports
Risk Factors:
Flexibility: 3 areas to consider
Jumping/training volume
Explore the compression and shear present in PFPS and how it might impact the patella
- at patellofemoral joint there is too much compression/shearing at joint
- crushing and grinding motions lead to pain in some way
Where is there patellar mis-aslignment typically?
misalignment of patella within groove
- some forces drag patella more to the lateral side
What types of knee overloading are there?
- overloading one side relative to other
- could also have overload - overtraining, body can’t adapt
What factors increase the likelihood of patellar misalignment?
- high volumes of training with not enough recovery lead to fatigue, worse form, more compression and loading with higher weight
- valgus: they have an even greater pull on patella and knee (CONSTANT PULL TO LATERAL SIDE)
What happens to force on the knee joint with flexion/extension?
- every time your knee bends your PT pulls
- the deeper flexed knee, the deeper compression is applied to patella/joint
- extension: quads contract and press patella in to femur
Tendinopathies range in severity - describe acute vs chronic
- acute (one time overload, reactive)
- chronic (disrepair, collagen breaking down but can’t fully recover, turns into tendinosis, disorganized weak, prone to injury)
What 3 areas where flexibility is a risk for patellar tendinopathy?
- quadriceps
- calves
- hip flexors and maybe also hamstrings
Which ROMs are tested for knee injuries?
- flexion
- extension
- medial rotation
- lateral rotation
Excessive motion can damage muscle and ligaments that cross it: what might acute hyperextension affect?
- any combination of 3 hamstrings most likely to fail
Excessive motion can damage muscle and ligaments that cross it: what might acute hyperflexion affect?
- any combination of quadriceps rectus femoris (cross hip)
- 3 vasti (do not cross hip)
Excessive motion can damage muscle and ligaments that cross it: what might valgus affect?
pes anserine group crosses (sartorius, gracilis, semitendinosis
What 2 additional actions should you consider testing?
- HIP testing! Lots of muscles cross the hip
- don’t need to do all 6 hip actions
- FLEXION and EXTENSION of hip
In which stage of healing do we get the most false positives? What does this mean for testing timelines post-injury?
- inflammatory stage
- most painful, bruising = everything hurts
- not a great time to be doing thoes tests
can try and do short testing before inflammatory stage, sometimes takes fluid a bit of time to move - even if we get past inflammatory stage, sometimes it takes fluid a bit of time to move
How does swelling impact out ability to test ROM?
- swelling fluid can limit movement, ROM you get from test at this time is not necessarily actual ROM
- no matter how much you want it to move the fluid stops you
- active knee extension and resisted knee extension won’t work out very well in this case (weak, not necessarily painful)
- passive or active flexion becomes very difficult also when knee has lots of fluid (can see 90 degrees when usually 140)
*feels like swelling sits at the back becuase it moves around the whole joint
What movements would be most affected if you tore the ACL
- extension
- either of the rotations, acl is pulled apart (ACL is 3 bundle ligament, diff parts fail ith different movements)
What movements would be most affected if you tore the PCL
- flexion
- when we flex, tibia translates posteriorly
- PCL fails
- less bothered by the rotations than ACL, will be primarily a flexion issue
What movements would be most affected if you tore the MCL or LCL?
- extension pulls mcl apart a little more (LCL too)
- rotation (eternal rotation of tibia for both MCL AND LCL)
*lateral rotation and extension pull these apart primarily
What movements would be most affected if the menisci were damaged?
- depends on which one is most injured
- we come down hard on menisci and grind, injury of compression rather than pulling apart
- medial meniscus is the most stressed when we go into lateral rotation
- posterior aspect of meniscus is most irritated with flexion
- anterior aspect of meniscus is most irritated with flexion
MEDIAL MENISCUS: external rotation
LATERAL MENISCUS: internal rotation irritates it
What are the special tests for anterior knee pain?
no specific tests with high reliability and validity, check mechanics during functional tasks (setp down, single leg squat, jumping, landing)
- watch and look for hints that mechanically they have room to improve
What are some hints that someone’s single leg squat could mechanically improve?
- in a valgus position
- quads are giving out (control/collapse/different in between legs)
- poor control of the trunk
- ankle: is dorsiflexion similar on both sides?
- pronation of the foot: do they drop into pronation right away or can they support arch?
- internal rotation stemming from hips
What muscle group helps prevent valgus position?
abductors of the hip
What’s a big focus of injury prevention/healing promotion in acute knee issues?
NEUROMUSCULAR CONTROL (about communication you have between nervous system and muscle)
- you could be swoe but if the timing of neural piece is wrong you get a delay ad possibly increase chance of injury
-step that involves muscle strength but takes it a step further
- ppl can respond quicker in high risk situations
There are generic programs that are provided to return to play athletes that contain PFABS: describe the components of this acronym
PLYOMETRICS (ballistic movement
FEEDBACK on landing techniques (coach you out of dangerous landing habits)
AGILITY (ability to quickly change direction)
BALANCE (working on balancing so later they can balance on uneven support system, maybe removing vision aspect)
STRENGTH
If you follow the PFABS injury prevention program, what is the relative risk of:
1. ACL injury
2. Knee injury
3. Female soccer lower extremity injury (hip, ankle, knee)
- 0.47 (53% lower chance this happens)
- 0.73
- 0.73
What is our goal for knee-dominant skills (ex SL hop or SL squat)
CONTROL/LIMIT valgues knee position and hip internal rotation
- INCREASE KNEE FLEXION and avoid full extension (hyperextension is one mechanism of injury)
- IMPROVE TRUNK CONTROL so they can land in a more stable way and not cause other asymmetries
Why do we want to increase knee flexion in injury prevention skills?
- don’t want to lock out knee, puts ACL/PCL at risk
- we want to absorb landing impact through knee flexion
Can taping help anterior knee pain?
- taping could reduce patellofemoral pain in some athletes
- adresses patella that likes to hang out on lateral side
- the tape won’t necessarily hold it there but you can impact it enough to make it less painful to do ADL
- use tough tape (like duct tape, “barf tape” XD)
- TOOL NOT SOLUTION
How can patellar tendon straps help anterior knee pain?
- has some padding or metal bar inside that adds pressure against the patellar tendon
- set it up so it lines up with more painful side, usually apex of patella
- some have velcro straps
- also calsled infrapatellar tendon strap
- applies counterpressure to reduce pain
There are a couple protocols for building up tendon to manage tensile loads, decribe the eccentric emphasis protocol
NOT GONNA DO heel drops for patellar tendon
Eccentric emphasis protocol
- put someone on block that elevates the heel, plantarflex at 20 degrees
- lower into single leg squat (60 degrees knee flexion from straight leg)
- working through eccentric protocol
There are a couple protocols for building up tendon to manage tensile loads, decribe the slow resistance protocol
- looking at speed and load
- moderate slow resistance (MSR 50-55% 1RM) or heavy slow resistance (HSR 90% 1RM)
- each rep 6-8 secs
What are 3 muscle groups we can consider training for anterior knee pain/broader patellofemoral syndrome?
- 2 at hip: HIP ABDUCTORS and HIP EXTERNAL ROTATORS (trying to limit opposite movements)
- Quadriceps! (if we can control a load we can limit risk of injury)
- need good amount of loading but not too much
What are some foot-targeted exercise and orthotic strategies?
- some ppl, especially pronators, might benefit from exercises that target the foot, smaller intrinsic muscles of the foot (foot doming, big toe push)
- teaches the foot to stabilize more effectively
- can put orthotics in to improve some of this while they are healing (more so from pronators/low arch)
- orthotics are IN ADDITION to strength exercises (not usefyl by itself)
How is the “sweep test” conducted and what does it assess?
looks for joint effusion, synovial fluid in joint
- sweeps palm on medial side of leg, leg up to thigh and see if there is any indication of synovial fluid excess in bulges/wierd movement (in vid shown in class, other videos show up-down sweep)
