Highlights from the recent Sports Medicine Australia conference 2019
The annual Sports Medicine Australia conference was held in the idyllic location of Twin Waters from 23-26th October 2019. Not only was it in a great location, but the academic program was jam packed with clinical gems.
Hamstring strain injury prevention, rehabilitation & sports performance: David Opar, Ryan Timmins, Ferghal Behan, Kate Beerworth, Jack Hickey, Scott Hulm
Measuring strength, architecture & running mechanics for determining risk of hamstring strain injury- David Opar
not the golden bullet
Although often studied, evidence of nordic strength is mixed
more research unlikely to find "the answer"
often measured due to increased accessibility
eccentric exercise is more important than measuring eccentric strength: expose them to eccentrics
single prospective study only showing shorter fascicle length predisposing to injury, so replication studies needed. Timmins et al 2016
more specific for biceps femoris injuries than knee flexor measure
accessibility and experience major limitation
still unknown if change in architecture influences risk of injury
measure 2-3 times across season
there might be some subtle differences in movement between injured and non injured but the difference is very small
small number of injured participants
laboratory based techniques limiting widespread application and research
espoused in practice, but the evidence is lacking
can it be changed, and if so is it time efficient to do so?
Running fast (95%+) regularly more important than mechanics? Have them run fast!
There is a sweet spot for exposure to fast running and likelihood of hamstring injury. Malone et al 2018
Hamstring muscular tendon length similar across speeds, but relatively linear increase with maximal force and maximal negative work. 80% speed does not equate to 80% force and negative work, need to hit higher speeds!!
Ryan Timmins: I hate Nordics what else can I do?
Why might the Nordic work?
Intensity of eccentric effort (supramaximal, eccentric overload with body weight)
Activation (extent of BF & MH activity)
Easy to plan: on field, no or minimal equipment needed, multiple people at once
Plus other possible reasons eg increased in series strain & positive adaptations
Razor curl as an alternative? Razor curls can increase nordic strength but did NOT increase fascicle length
Take home messages:
Nordics aren’t the only exercise option available- just the one that ticks the most boxes
Including additional exercises with the Nordic can complement training goals & balance b/w prevention & performance
However if using alternatives on their own (without Nordics)- program for the adaptation desired & determine what aspect is to be sacrificed
Dosage of Nordics: Ferghal Behan
Nordic hamstring and performance:
improved sprint time (Ishoi et al 2018)
10m sprint time (Ishoi et al 2018, Siddle et al 2019
change of direction (Siddle et al 2019)
minimum effective dose is different for eccentric strength & architecture
low dosage enough for strength (2 x 4 reps once per week), higher volumes are required for changes in architecture
higher dosage results in greater improvements
Higher dosage also had higher amounts of DOMS
There is yet to be determined a minimal dosage for nordics
High exercise doses not required for strength or fascicle length
minimum effective dose varies for both
minimum effective dose for performance?
high dosages may increase pain
find the "goldilocks" prescription zone
When to start running post hamstring injury?
Respect tissue healing!
Return to running within 4 days of injury resulted in significantly higher risk of subsequent injury
Notably extending this off legs period >4days did not delay RTP time (Stares et al 2018)
"To begin with the end in mind"
Respect tissue healing/objective criterion- load alternatively early
Limit deconditioning - plan backwards to build chronic low speed/HIR loads/aerobic fitness (monitor key clinical tests)
Re-develop acceleration & horizontal force capacity- sleds/resisted running/RSA
accumulate & periodize adequate HSR volumes- prepare for "worst case" scenario
conscious distribution of multiple high velocity exposures >85%-100% "run fast & often". 5-8 sessional exposures of maximal velocity over 4weeks had an 85% decrease in HSI
Timmins, R. G., et al. (2016). "Short biceps femoris fascicles and eccentric knee flexor weakness increase the risk of hamstring injury in elite football (soccer): a prospective cohort study." Br J Sports Med 50(24): 1524-1535.
Malone, S., et al. (2019). "Can the workload-injury relationship be moderated by improved strength, speed and repeated-sprint qualities?" J Sci Med Sport 22(1): 29-34.
Behan, F., et al. (2019). "The dose response of Nordic hamstring exercises on biceps femoris long head architecture and eccentric hamstring strength." Journal of Science and Medicine in Sport 22: S71-S72.
Ishoi, L., et al. (2018). "Effects of the Nordic Hamstring exercise on sprint capacity in male football players: a randomized controlled trial." J Sports Sci 36(14): 1663-1672.
Siddle, J., et al. (2019). "Acute adaptations and subsequent preservation of strength and speed measures following a Nordic hamstring curl intervention: a randomised controlled trial." J Sports Sci 37(8): 911-920.
Stares, J., et al. (2018). "How much is enough in rehabilitation? High running workloads following lower limb muscle injury delay return to play but protect against subsequent injury." J Sci Med Sport 21(10): 1019-1024.
Phil Glasgow: Optimizing load to maximise outcomes
Rehab= training in the presence of injury
Instead of injury prevention= increased robustness
Injury prevention=Increased robustness
Rehabilitation=Effective return to sport
Performance enhancement=Improved performance
Early loading is Optimal loading
Principles of training do NOT change when someone is injured
Important to ask the patient what training they have done in the past? Even if it is a long time ago, they will still have the myo nuclei present, and will tend to adapt faster to re loading
Optimal loading is:
early but controlled
Early mobilization improves short term short term functional outcome. Unloaded ligaments are half as stiff
sufficient overload is needed
novel loading (multidirectional load i.e. torsion)
load little and often: recent player with bone injury they trained him 6 times per day
site and activity specific
Assessment items to consider
ask your athletes about why they think they are hurting: what is their understanding of their condition?
Ask about more than just pain: think of all the things that can influence pain (sleep, stress, anxiety, fear ect)
Measure the functional state of the pain system? Assessing temporal summation via exercise reps (ie movement evoked pain)
A.Prof Tash Stanton “Pain in athletes- integrating new insights from pain neuroscience into assessment & treatment
Treatments informed by pain science
Increasing pain knowledge
Pain science based movement prescription
Using sensory input to our advantage
Words hurt: Use language to HELP our athletes in pain
"Movement will be painful at first- like a sprained ankle - but will get better as you get active"
"Our tissues heal best through loading- gradually increasing your activity is the very best thing you can do"
"You knee/hip/back is strong & robust- let's take it out for a test drive"
Message:“Movement is the best thing for you to help you heal, and you are safe to move”
The expectation of how pain influences performance...influences ACTUAL performance
Negative group: "pain disturbs cognitive processes like visual processing and memory"
Positive group: "pain enhances cognitive processes like visual processing and memory"
Positive group showed significant improvement in cognitive task
(Sinke et al, Cortex 2016)
Applying pain based movement prescription for athletes in pain:
Unpair the movements that hurt with that EXACT movement
if elbow extension during a backhand is painful, find new ways of achieving elbow extension that do not mirror the exact tennis stroke motion ie yoga downward dog, dance, tai chi
Use different movement pattern to create a new representation and to promote increased diversity in representations
Pain is there to protect, it doesn't necessarily tell us about damage
this often means that searching for peripheral "cause" is not fruitful
just because you feel pain doesn't mean you are injured
Our systems can become over-protective
Pain occurs when evidence of the need to protect outweighs the evidence of safety
Our words matter
Understanding pain is an effective treatment
We can use movement to help our system "unlearn" associations between pain and activity
We can use vision and sound to our advantage
Phil Glasgow: Training load monitoring & management in athletes
Robustness: the capacity to consistently engage in training & games with maximal effort
Important to look at what you need to improve in an individual in addition to their injury for which you are treating them. Once you have identified these pillars of improvement, you then need to establish how to assess & monitor these.
For example you identify the following areas for improvement in an athlete, with the ways to measure listed:
Neural activation: hand held dyno, rate of force development (RFD), jumps
Motor control: movement quality 3C's, adaptability, outcome/execution
Mutli-segmental mobility (rotation): tension arc, RFD, sport specific pattern
High speed running: distance, density, Vmax
Psychological factors: POMS, hyper vigilance, anxiety
Posterior chain strength: hand held dyno, nordic hamstring strength, isokinetic dyno
Things to consider in all injuries
Hamstring & groin example in Rugby Union player
Tissue quality & flexibility
Extension ROM > neutral
Seated rotation ROM >30 deg, symmetry <10%
Hip/Low back mobility:
Sit & reach: Min 6-16, SD Flag >1SD
Hip IR 90/90 >20deg
Hip ER 90/90 >45deg
Hip ext: 0-10deg
Hip ROM ABD/ADD + IR/ER
Normal: 160 deg
Kicker: 180 deg
Skipping a rhythm
Plyometric: Hop/Bound: rotational, lateral, linear
Squatting, lunging & hinging
Eccentric strength Nordboard: 400-500N, <10% asymmetry
Concentric strength: Groin squeeze 200-300mmHg, Symmetry <10%, SD flag >1SD
Eccentric/concentric strength: Posterior chain: 2 leg RDL 1.5xBW, 1 leg RDL 0.75 x BW, Rear leg elevated split squat: 0.75 x BW
Unbreakable in the following positions: Hamstring 90/90 position, Hip 90/90 position
Load: Acute:Chronic spike for: distance, high speed running distance, acceleration distance, acceleration efforts, plyos
Max Velocity: Achievability & Consistency: 2-3 x 90% every 7-10 days
Kicking load & consistency
Repeated sprint attempts & recoverability
Exposure consistency: distance, high speed running distance, multi direction, acceleration, plyos
Shoulder & rotator cuff in Rugby Union player example
Tissue quality & flexibility:
Extension ROM > neutral
Seated rotation ROM >30 deg, symmetry <10%
External rotation: 90 deg at 90/90
Internal rotation: 30 deg at 90/90
Technique: scrum, line-out, maul, tackle, carry, clean out
Up push, pull & rotation
Reactive strength: Force plate: explosive push up, reactive strength index & force
Concentric strength: Int & Ext rotation: Handheld dyno 90/90 position, 1:0.8 strength ratio, <10% asymmetry
Push & Pull strength: Horizontal/vertical pull: 1.2-1.5 x BW, Horizontal push: 1.2-1.5 x BW
Unbreakable: External rotation in 90/90 position, Internal rotation in 90/90 position
Isometric testing: Force plates: ASH test
Tri-planar shoulder cuff capacity
Collision load: scrum, maul, tackle, carry
Joanne Kemp- Evidenced based management of Hip-related pain
Things to consider to formulate diagnosis during physical examination
Differentiating between hip and low back
Walking with a limp (7x more likely hip than spine)
Pain in groin/anterior hip (7x more likely hip than spine)
Reduced hip IR ROM (14x more likely hip than spine)
No change in symptoms with repeated lumbar movement (SN 92% ruling out lumbar spine)
Negative extension/rotation lumbar spine (SN 100% ruling out lumbar spine)
Negative SLR (SN 97% ruling out lumbar spine)
Negative slump test (SN 87% ruling out lumbar spine)
Negative thigh thrust (SN 82% ruling out lumbar spine)
No pain over SIJ (ruling out SIJ)
No pain in anterior hip/groin? It will NOT be intra-articular hip related nor likely to be hip flexor, adductor or inguinal related pain
FADDIR to rule OUT having intra articular hip issues
FABER- poor to fair test to rule in and rule out
Adductor squeeze test: positive you can be confident that it is adductor related pain BUT a negative test doesn’t rule out adductor related pain
Adductor and extension weakness in Both sexes
Abductor strength more important to measure in WOMEN
Re-measure all strength at 6-8 weeks, but measure the most impaired at every visit.
Joanne doesn’t measure hip external and internal strength anymore- some argue quadratus femoris plays an important role, but it’s action is more as an adductor.
Joanne uses make AND break testing
Greater hip flexion range is most important to measure- normal 110-120
Hip internal rotation doesn’t particularly change post hip operation.
Measure hip flexion range at the start and end of treatment
Internal rotation: measure at initial but UNLIKELY to change with treatment
single leg hop for distance
Single leg bridge to fatigue