MacDonald, D., G.L. Moseley, and P.W. Hodges, Why do some patients keep hurting their back? Evidence of ongoing back muscle dysfunction during remission from recurrent back pain. Pain, 2009. 142(3): p. 183-8. https://www.ncbi.nlm.nih.gov/pubmed/19186001 



Clark, N., Voight, M., Campbell, A., Pierce, S., Sells, P., Cook, R., Henley, C., Schiller, L. . (2017). The relationship  between segmental  rolling ability and lumbar multifidus activation time. Int J Sports Phys Ther, 12(6), 921-930. 
​
Tucker, K.J. and P.W. Hodges, Motoneurone recruitment is altered with pain induced in non-muscular tissue. Pain, 2009. 141(1-2): p. 151-5. https://www.ncbi.nlm.nih.gov/pubmed/19095357  


Tucker, K., et al., Similar alteration of motor unit recruitment strategies during the anticipation and experience of pain. Pain, 2012. 153(3): p. 636-43. https://www.ncbi.nlm.nih.gov/pubmed/22209423  


Shadmehr, A., Z. Jafarian, and S. Talebian, Changes in recruitment of pelvic stabilizer muscles in people with and without sacroiliac joint pain during the active straight-leg-raise test. J Back Musculoskelet Rehabil, 2012. 25(1): p. 27-32. https://www.ncbi.nlm.nih.gov/pubmed/22398264  




Renkawitz, T., D. Boluki, and J. Grifka, The association of low back pain, neuromuscular imbalance, and trunk extension strength in athletes. Spine J, 2006. 6(6): p. 673-83. https://www.ncbi.nlm.nih.gov/pubmed/17088198  


Radebold, A., et al., Impaired postural control of the lumbar spine is associated with delayed muscle response times in patients with chronic idiopathic low back pain. Spine (Phila Pa 1976), 2001. 26(7): p. 724-30. https://www.ncbi.nlm.nih.gov/pubmed/11295888  


Park, J. and J.T. Hopkins, Induced anterior knee pain immediately reduces involuntary and voluntary quadriceps activation. Clin J Sport Med, 2013. 23(1): p. 19-24. https://www.ncbi.nlm.nih.gov/pubmed/23103783  


Bank, P.J., et al., Motor consequences of experimentally induced limb pain: a systematic review. Eur J Pain, 2013. 17(2): p. 145-57. https://www.ncbi.nlm.nih.gov/pubmed/22718534  


Bley, A.S., et al., Propulsion phase of the single leg triple hop test in women with patellofemoral pain syndrome: a biomechanical study. PLoS One, 2014. 9(5): p. e97606. https://www.ncbi.nlm.nih.gov/pubmed/24830289  


Cholewicki, J., et al., Neuromuscular function in athletes following recovery from a recent acute low back injury. J Orthop Sports Phys Ther, 2002. 32(11): p. 568-75. https://www.ncbi.nlm.nih.gov/pubmed/12449256  


Cholewicki, J., et al., Delayed trunk muscle reflex responses increase the risk of low back injuries. Spine (Phila Pa 1976), 2005. 30(23): p. 2614-20. https://www.ncbi.nlm.nih.gov/pubmed/16319747  


de la Motte, S., B.L. Arnold, and S.E. Ross, Trunk-rotation differences at maximal reach of the star excursion balance test in participants with chronic ankle instability. J Athl Train, 2015. 50(4): p. 358-65. https://www.ncbi.nlm.nih.gov/pubmed/25531142  


Deschamps, T., et al., Influence of experimental pain on the perception of action capabilities and performance of a maximal single-leg hop. J Pain, 2014. 15(3): p. 271 e1-7. https://www.ncbi.nlm.nih.gov/pubmed/24275316  


Elsig, S., et al., Sensorimotor tests, such as movement control and laterality judgment accuracy, in persons with recurrent neck pain and controls. A case-control study. Man Ther, 2014. 19(6): p. 555-61. https://www.ncbi.nlm.nih.gov/pubmed/24957711 


Graven-Nielsen, T., et al., Stimulus-response functions in areas with experimentally induced referred muscle pain--a psychophysical study. Brain Res, 1997. 744(1): p. 121-8. https://www.ncbi.nlm.nih.gov/pubmed/9030420  


Graven-Nielsen, T., et al., Inhibition of maximal voluntary contraction force by experimental muscle pain: a centrally mediated mechanism. Muscle Nerve, 2002. 26(5): p. 708-12. https://www.ncbi.nlm.nih.gov/pubmed/12402294  


Graven-Nielsen, T., P. Svensson, and L. Arendt-Nielsen, Effects of experimental muscle pain on muscle activity and co-ordination during static and dynamic motor function. Electroencephalogr Clin Neurophysiol, 1997. 105(2): p. 156-64. https://www.ncbi.nlm.nih.gov/pubmed/9152211  


Greene, H.S., et al., A history of low back injury is a risk factor for recurrent back injuries in varsity athletes. Am J Sports Med, 2001. 29(6): p. 795-800. https://www.ncbi.nlm.nih.gov/pubmed/11734495  


Henriksen, M., et al., Experimental quadriceps muscle pain impairs knee joint control during walking. J Appl Physiol (1985), 2007. 103(1): p. 132-9. https://www.ncbi.nlm.nih.gov/pubmed/17412791  


Henriksen, M., et al., Adaptations in the gait pattern with experimental hamstring pain. J Electromyogr Kinesiol, 2011. 21(5): p. 746-53. https://www.ncbi.nlm.nih.gov/pubmed/21824788  


Hodges, P.W. and G.L. Moseley, Pain and motor control of the lumbopelvic region: effect and possible mechanisms. J Electromyogr Kinesiol, 2003. 13(4): p. 361-70. https://www.ncbi.nlm.nih.gov/pubmed/12832166  


Hodges, P.W., et al., Experimental muscle pain changes feedforward postural responses of the trunk muscles. Exp Brain Res, 2003. 151(2): p. 262-71. https://www.ncbi.nlm.nih.gov/pubmed/12783146  


Janssens, L., et al., Greater diaphragm fatigability in individuals with recurrent low back pain. Respir Physiol Neurobiol, 2013. 188(2): p. 119-23. https://www.ncbi.nlm.nih.gov/pubmed/23727158  



Moseley, G.L., et al., The threat of predictable and unpredictable pain: differential effects on central nervous system processing? Aust J Physiother, 2003. 49(4): p. 263-7. https://www.ncbi.nlm.nih.gov/pubmed/14632625  


Palmieri-Smith, R.M., et al., Pain and effusion and quadriceps activation and strength. J Athl Train, 2013. 48(2): p. 186-91. https://www.ncbi.nlm.nih.gov/pubmed/23672382
​

For an increase in swimming speed of 10%, decrease your drag by 3% or increase your power by 30%. 

Read that again. 

Now, it seems like it's easier to drop 3% drag than gain 30% power. You're mostly right. IF.....IF the drag is related to swimming technique - that's a motor control issue. It might be harder to change drag if the technique relates to a mobility issue that prevents being able to get INTO a streamlined position. That takes trained movement assessment to reveal the region of concern, then trained local biomechanical testing to find the reason for the regional mobility dysfunction, then trained reset techniques to bring the local biomechanical dysfunction up to minimum competency. 

Here's a video of a Chinese swimmer doing a Y-hold with flutter kick. What can you see that might limit speed according to the above equation?

Why the new system?
We know that the return of impaired measures of isolated strength, joint mobility, muscle flexibility and balance can be normal or can occur while movement patterns can still represent dysfunction. 

Likewise, it is possible for some performance parameters to fall within normal limits even when acceptable movement patterns are not present.

The new system honours a simple understanding of a complex batch of science around movement learning and strength and conditioning that relates to injury. Get in the game, to stay in the game, win the game.

Click play on the sound file below to listen to these important revelations, extracted from the "Movement" book, by Gray Cook, with Dr. Lee Burton, Dr. Kyle Kiesel, Dr. Greg Rose & Milo F. Bryant. 

Click here to learn more about the Functional Movement Systems. 



To buy the "Movement" book, click here.

I want to use the topic to refer to you. Your rehab. Your training. Your deepest desires. 

Did you know? In the Chinese Harvest Moon Festival, the death rate drops 35% below average in the week of this festival, then rises by the same amount in the week following the festival. 

Did you know - three US Presidents have died on July 4th? John Adams, Thomas Jefferson and James Monroe.

What does this mean? 

At times of importance - to these people, national importance - their impending death is held off by highly energetic intent to remain alive long enough for these times. Imagine that. You can will yourself to stick around until something important has passed. 

How is that relevant to you? 

A pre-participation evaluation should include markers of health. They are typically looking "for signs or symptoms of underlying disease, or who may be at higher risk of an adverse event during exercise" (Essa, 2018)

The presence of increased risk in a screen should lead to further assessment.

Physical Activity Readiness Questionnaire (PAR-Q)
The PAR-Q has been designed to identify the small number of adults for whom physical activity may be inappropriate or those who should have medical advice concerning the type of activity most suitable for them.

Answer yes or no to the following questions:

Has your doctor ever said that you have a heart condition and that you should only do physical activity recommended by a doctor?
Do you feel pain in your chest when you do physical activity?
In the past month, have you had chest pain when you were not doing physical activity?
Do you lose your balance because of dizziness or do you ever lose consciousness?
Do you have a bone or joint problem that could be made worse by a change in your physical activity?
Is your doctor currently prescribing drugs (for example, water pills) for your blood pressure or heart condition?
Do you know of any other reason why you should not do physical activity?

If you answered yes:

If you answered yes to one or more questions, are older than age 40 and have been inactive or are concerned about your health, consult a physician before taking a fitness test or substantially increasing your physical activity. You should ask for a medical clearance along with information about specific exercise limitations you may have.

In most cases, you will still be able to do any type of activity you want as long as you adhere to some guidelines.

If you answered no:

If you answered no to all the PAR-Q questions, you can be reasonably sure that you can exercise safely and have a low risk of having any medical complications from exercise.

It is still important to start slowing and increase gradually. It may also be helpful to have a fitness assessment with a personal trainer or coach in order to determine where to begin.

When to delay the start of an exercise program:

If you are not feeling well because of a temporary illness, such as a cold or a fever, wait until you feel better to begin exercising.
If you are or may be pregnant, talk with your doctor before you start becoming more active.
Keep in mind, that if your health changes, so that you then answer "YES" to any of the above questions, tell your fitness or health professional, and ask whether you should change your physical activity plan.

ESSA designed PPE Stage 1 Questionnaire
Exercise and Sports Science Australia (ESSA), in association with Sports Medicine Australia (SMA) devised a PPE, with some elements that pass criteria mentioned above.

Where this specific evaluation fails is in the following recommendation: 
"IF YOU ANSWERED ‘NO’ to all of the 7 questions, and you have no other concerns about your health, you may proceed to undertake light-moderate intensity physical activity/exercise." This recommendation fails to evaluate movement-based risk factors, thus presents probable false negatives for exercising. 

ESSA, 2018. https://www.essa.org.au/for-gps/adult-pre-exercise-screening-system/

F-MARC designed PPE​
This PPE fails to account for a major risk factor in injury - motor control. 

It is recommended that the FMS, SFMA and FCS are used as appropriate (in the absence of pain, presence of pain/injury and passing of the FMS) in addition to specific tests within the F-MARC PPE, for soccer players.

​SCREEN first for competency and risk to tell you whether you need to do more ASSESSMENT for causes/contributing factors/complicating factors, ie regress, or to proceed to TEST capacity, ie progress. 

Any of these could be used in Pre-Participation Evaluations (PPE's).

Choose a screen, assessment battery or test battery that reveals the ability to respond, then adapt to external and internal stimuli. Recognise that the heirarchy of evaluation is:
1) below bodyweight 
2) at bodyweight
3) above bodyweight

Assessments should reveal either the cause/contributing factor or complicating factor to why the person is rated as below competence or at below minimum capacity. A test that follows from a competent assessment and screen should also reveal cause/contributing factor or complicating factor to why the person is rated as below competence or at below minimum capacity.

Recommendations made in this learning module honour the above. Those evaluations that do not clearly honour the above are not recommended.

There are three areas to evaluate pre-participation. 

Health systems of the human. 
Function as it relates to movement competency as a human, not as a human within a sport.
Performance as it relates to fundamental human movement capacity.
Performance as it relates to sports-specific movement capacity.

Evaluations should reveal competency and capacity separately to avoid confusion as to what is the limiting factor in a persons capacity. For example, an individual who has movement competency issues and is then tested for capacity will most likely demonstrate reduced capacity - to the less focussed assessor, the deficits may be blamed on reduced capacity, directing interventions there, failing to recognise that reduced competency affects expression of capacity. Some evaluations combine competency and capacity in one test, a flaw in testing. For example, consider an individual who is tested for single hop for distance but who has an underlying ankle dorsiflexion limitation, below competent. This individual is less likely to express sufficient force production to hop a minimum acceptable distance, and/or is less likely to express sufficient dynamic motor control and/or force absorption to land with competence. A reduced hop distance, below minimum acceptable, might be seen as a capacity problem if the underlying mobility or motor control problems in the lower quarter and trunk were NOT first revealed with a competency screen. 

Recommendations made in this mindmap are held against four criteria: 

1. Is the evaluation reliable? 
2. Is there some evidence of validity of the findings from the evaluation?
3. Is the evaluation sensitive to change?
4. Is it portable and easy to administer once trained?

Evaluations that go some way towards addressing the above criteria are given preference in recommendation.

Reliability
A pre-participation evaluation should be reliable between sessions and between individual evaluators. This provides objectivity and improves communication between testers.

Any exisiting pre-participation evaluation should be scrutinised for the presence or absence of reliability studies.

Validity
Construct validity
The degree to which a test measures what it claims, or purports, to be measuring. 

For example, a pre-participation evaluation is typically looking "for signs or symptoms of underlying disease, or who may be at higher risk of an adverse event during exercise" (Essa, 2018)

The presence of increased risk in a screen should lead to further assessment. See individual injury discussions within this module for risks and predisposing factors for ACL, patellofemoral pain, shoulder tendinopathy and lateral ankle injury.

ESSA, 2018. https://www.essa.org.au/for-gps/adult-pre-exercise-screening-system/ 

Criterion validity​
Criterion or concrete validity is the extent to which a measure is related to an outcome. Criterion validity is often divided into concurrent and predictive validity. 

Concurrent validity refers to a comparison between the measure in question and an outcome assessed at the same time.

Predictive validity, on the other hand, compares the measure in question with an outcome assessed at a later time.

Concerns have been raised whether the variable ACL return-to-sport criteria utilized in current clinical practice are stringent enough to achieve safe and successful return-to-sport. For example, strength and hop tests have been shown to overestimate knee function after ACL injury. This is an example of the measure in question (limb symmetry index cut points in strength and hop tests) NOT being comparable in importance to estimated pre-injury capacity. Applying limb-symmetry index's of 90%, which is common in clinical practice, is an example of poor criterion validity.

Wellsandt, E., Failla, M. J., & Snyder-Mackler, L. (2017). Limb Symmetry Indexes Can Overestimate Knee Function After Anterior Cruciate Ligament Injury. J Orthop Sports Phys Ther, 1-18. doi:10.2519/jospt.2017.7285 http://www.ncbi.nlm.nih.gov/pubmed/28355978 

Content validity
Content validity (also known as logical validity) refers to the extent to which a measure represents all facets of a given construct. 

For example, a pre-participation evaluation may lack content validity if it only assesses the range of motion and strength of an individual, ie the part specific competence and capacity, but fails to take into account the behavioral dimension, or pattern-specific competence and capacity. 

Further, a pre-participation evaluation may lack content validity if it does not evaluate seemingly unrelated elements. For example, the essence of regional interdependence is that pain or movement-below-competence anywhere can affect a movement pattern in the whole kinetic chain. 

Regional interdependence: Wainner, R. S., Whitman, J. M., Cleland, J. A., & Flynn, T. W. (2007). Regional interdependence: a musculoskeletal examination model whose time has come. J Orthop Sports Phys Ther, 37(11), 658-660. doi:10.2519/jospt.2007.0110 https://www.ncbi.nlm.nih.gov/pubmed/18057674 

Modifiable and sensitive to change​
A measure used in a pre-participation evaluation should be modifiable. For example, a pre-participation evaluation which only includes the presence or not of previous injury is one that is revealing that which is not modifiable. A PPE should include indicators, with criteria, of modifiable risk factors. The PPE itself should be able to detect when changes to those risk factors have occurred, ie the scale of measurement should reflect significant change, for better or worse.

Easily administered once trained, and portable
All PPE's require technical instruction for testers, with reflective practice. The purpose is to bring all testers up to not miss important information. This reduces false negatives. It also ensures individuals are directed onwards for higher level testing when they pass minimum levels of competency, ie normal risk. It also ensures individuals are directed appropriately for further assessment when they do not pass minimum levels of competency. For example, an individual who's resting blood pressure is 150/110 has undergone a reliable test, with construct validity of a measure that is modifiable, sensitive to change, using an easily administered test that is portable, and which directs the person to be further assessed as to what might be causing, contributing or complicating normal blood pressure. 

In PPE's that relate to risk factors for ACL injury, there exist baseline screens and assessments that can be taught, easily administered in small time periods, require minimal equipment that is portable and that can be reliable, valid for risk factors, capture modifiable risks and are sensitive to change. 

Q: "How do you define screen, test, assess, and evaluate?"
A: Screen, test and assess are all versions of evaluate.

Evaluate is the "parent" word that is a verb, to form an idea of the value of the subject.

A screen is a evaluation that filters a subject into two main categories - pass or fail. Another way to describe the category is - competent or not. The screen is there to look for RISK and COMPETENCE of movement. A screen is NOT for predicting injury. A movement screen does not tell us what is wrong. It only tells us that some movement is below acceptable. 

An assessment is a evaluation that reveals DISABILITY. An assessment is used to tell us what is contributing to the individual having risk, or incompetence.

A test is an evaluation to tell us about the ABILITY of the individual. When an individual passes a screen, we know they are competent, but we don't know about their capacity, so we test them for ABILITY.

Like any injury, a pre-participation evaluation can be interpreted in two ways: 

1. Evaluate someone who has not been injured - the aim of the evaluation is to look for readiness for the event, generally and specifically; and 
2. Evaluate someone who HAS been injured - the aim of the evaluation is to look for readiness for the event in addition to structural integrity of the injured part.

For example, a person who has suffered a lateral ligament sprain should have their ligament evaluated for structural integrity, in addition to potential causes, contributing factors and complicating factors. 

The following guidelines for obtaining a diagnosis are up-to-date and based on information from the Cochrane Collaboration, an organisation whose mission is “to ensure that patients receive effective interventions for the best health outcomes based on up-to-date evidence, and that healthcare providers have up-to-date and easy access to the latest evidence.” 
• Clinical tests include those for disruption of ligaments, and include the anterior drawer test of ATFL function and inversion tilt test of both ATFL and CFL function. The reliability of these tests has been questioned in recent systematic reviews (Hubbard & Hicks-Little, 2008), and it has been suggested that these tests alone are not sufficient to accurately determine the extent of ligament damage because of the large variation in individual variation .

Containing an evaluation to these two tests would do a disservice to the individual, as they do not evaluate the contribution of the part to the patterns and power required for the activity. See below for PPE's that further evaluate these elements.

www.cochrane.org

Hubbard, T. J., & Hicks-Little, C. A. (2008). Ankle Ligament Healing After an Acute Ankle Sprain: An Evidence-Based Approach. J Athl Train, 43(5), 523-529.

The shoe to surface interface has been strongly correlated with ACL injury (Pope, 2002) such that rubber matting, in combination with rubber-soled shoes was a direct cause of ACL injuries in Australia military recruits. It has also been suggested that such interfaces may indirectly increase risk via changing human movement factors (Letha et al, 2006)

Pope, R. P. (2002). Rubber matting on an obstacle course causes anterior cruciate ligament ruptures and its removal eliminates them. Mil Med, 167(4), 355-358.  https://www.ncbi.nlm.nih.gov/pubmed/11977890 

Lambson, R. B., Barnhill, B. S., & Higgins, R. W. (1996). Football cleat design and its effect on anterior cruciate ligament injuries. A three-year prospective study. Am J Sports Med, 24(2), 155-159. doi:10.1177/036354659602400206

Robey, J. M., Blyth, C. S., & Mueller, F. O. (1971). Athletic injuries. Application of epidemiologic methods. Jama, 217(2), 184-189. https://www.ncbi.nlm.nih.gov/pubmed/5108781

Letha, Y. G., Marjorie, J. A., Elizabeth, A. A., Roald, B., Bruce, D. B., Marlene, D., . . . Bing, Y. (2006). Understanding and Preventing Noncontact Anterior Cruciate Ligament Injuries: A Review of the Hunt Valley II Meeting, January 2005. Am J Sports Med, 34(9), 1512-1532. https://doi.org/10.1177/0363546506286866