Thread of my notes from the lectures to follow .....
@ACLStudyDay@Dusty_Grooms The brain functions as a hierarchy of networks that promote movement. Everything eventually links to the motor cortex.
Environmental context influences how well a patient looks in different environments.
@ACLStudyDay@Dusty_Grooms Neuroplasticity results in:
- incr cortical area assoc w/ the skill (the more you do a skill, the more your brain dedicates to it)
- new neuron support cells to facilitate skill
- improves neural efficiency (as ability incr, neural activity req decr for more complex tasks)
@ACLStudyDay@Dusty_Grooms ACL Injury results in:
- altered sensory info (somatosensory) into primary sensory cortex
- brain tries to maintain neural drive to motor cortex --> gets missing primary sensory info (visual, vestibular)
Creates spinal inhibition + motor neuron disruption = disrupted afferent signal
Results in arthrogenic muscle inhibition. Need CNS re-organization to get pre-injury motor control.
@ACLStudyDay@Dusty_Grooms Exam of brain activation pattern:
- people w/ high risk landing strategy have add'l brain activation patterns
- these patterns are activated in people AFTER injury (premotor planning, cognitive region activity)
MAYBE can address to reduce initial AND post-injury risk?
Motor performance = ability to perform a specific motor task
Motor learning = transfer of trained, rehearsed mov't patterns/skill to AUTOMATICA and robust to unanticipated events
@ACLStudyDay@Dusty_Grooms Motor performance can be TEMPORARILY affected by motivation, stress, attention, fatigue ... but these are temporary.
Motor performance shouldn't be equated 100% with motor learning.
For highly complex tasks, want pt to be initially very focused to get good performance.
@ACLStudyDay@Dusty_Grooms Motor learning:
"The ability to generalize learned motor skills enables us to modify our movement strategy in novel situations."
Explicit learning = can recall the steps or processes of the motor task
** concentrated in fewer brain areas
Implicit learning = you can't exactly describe what you did to do the task
** highly distributed across multiple brain regions
@ACLStudyDay@Dusty_Grooms Stages of Motor Learning: 1) Cognitive: Skill acquisition. Lots of mistakes, high performance variability 2) Associative: start to consolidate/develop skills - slow improvement in performance, variability decr 3) Autonomous: indpt, mastered motor skill - adapt to new situations
Practice variability leads to optimal learning, better ability to transfer motor skills from one situation to another (novel).
(Obviously, millions of errors not ideal, but some errors, that can be corrected, are safe for adaptation)
@ACLStudyDay@Dusty_Grooms Error correction:
Start with motor plan, do action, get feedback (ankle inverts and hurts), know you have an error --> either correct immediately or update motor plan for next time.
Brain determines if predicted outcome equals what happens - helps w/ error detection/correction
Repetition is needed but repetition of the same task isn't going to help in the long term. Require problem-solving through error detection/correction.
@ACLStudyDay@Dusty_Grooms Scheduling practice in more of a distributed fashion (eg, circuit training) can help with improving motor planning/error detection.
If you mass practice (eg, do same thing over &over), performance improves but the motor planning doesn't transfer. May be impt for fatigue tho
@ACLStudyDay@Dusty_Grooms Feedback:
- knowledge of performance: tell them exactly what to do
- knowledge of results: get the outcome to happen
@ACLStudyDay@Dusty_Grooms Usually in PT, we want performance to be same as results (eg, good mov't pattern during motor skill). Initially start w/ explicit feedback (PT gives feedback), progress to implicit feedback (they know what did right/wrong)
@ACLStudyDay@Dusty_Grooms Consider autonomy support:
- ask the patient what they want to do in a session (give choices, all which meet your goals)
- ask the patient when they want feedback or how often
@ACLStudyDay@Dusty_Grooms Enhanced Expectancies: (for pts w/ high physical ability but low confidence)
"Wow you're doing better than others at this stage / peer matched controls"
Ex: during squat
- internal: keep knees from moving inward
- external: aim knees towards the cones
- internal: don't lose balance
- external: keep bar level
**Internal feedback helps people move better right away but not ability in novel tasks
@ACLStudyDay@Dusty_Grooms Summary:
- pt should be active participant in planning, problem-solving of mov'ts
- practice allows some errors to enhance learning
@ACLStudyDay@Dusty_Grooms As therapist, identify:
- goal of task
- what it should look like
- what feedback is ESSENTIAL vs DETRIMENTAL to learning
- where the pt's attention should be during practice
• • •
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@MarkusWalden "ACL injuries in men's professional football: a 15-year prospective study on time trends and return-to-play rates reveals only 65% of players still play at the top level 3 years after ACL rupture" bjsm.bmj.com/content/50/12/…
FREE to download
@MarkusWalden In their database:
- Few career-ending injuries (1.8%)
- Approx 7% retear rate w/in 1 yr post #ACLR
Are these re-injuries failures? Or a deliberate high-risk decision? Interesting question.
Explosive strength = the capacity to generate FORCE as QUICKLY (<200ms) as possible. Often quantified as rate of force development (RFD).
Impt bc it's FUNCTIONALLY more relevant than max strength - not just for athletes, but even unexpected perturbations in ADL.
Explosive strength influenced by speed of motor neuron recruitment &discharge rate.
Discharge rate reduced w/ disuse, aging, pathology but has HUGE adaptability to training.
@DrKateWebster At ALL LEVELS OF PARTICIPATION, females are at greater risk for #ACL injury.
Overall, elite athletes: 83% return to pre-injury level
Elite females: Also 83%!
(incl handball, soccer, alpine skiing/snowboarding, basketball)
@DrKateWebster Time for RTS:
- No sex difference (Walden et al, KSSTA 2017)
- NCAA Division 1 soccer: cleared at 6 mths (Howard 2015)
- WNBA (Namdari 2011): 11.8 mths
On to topic #2 from @ACLStudyDay home study session:
Return to run post-ACLR with @rwilly2003 ! Notes to follow in this thread...
@ACLStudyDay@rwilly2003 Resolving basic fundamentals is impt prior to running - edema, ROM, strength, etc - or these impairments may persist/be magnified once pt returns to running
@ACLStudyDay@rwilly2003 Recreational running may become exercise of choice for some athletes who choose NOT to return to pre-injury sport