Using Action Observation to facilitate Strength & Conditioning Coaching

As part of my Honours research, I investigated the effectiveness of using action observation (AO) in teaching athletes a novel skill of performing the power clean exercise. I thought I’d share an insight on the background of AO and the findings of the investigation for those that prefer a quick snapshot as opposed to reading the entire scientific publication. This is just a bullet point summary with a few graphs and figures included.

The purpose of the investigation was to;

  1. determine whether the use of AO would better/faster facilitate the learning of a complex and novel RT exercise and;
  2. if improvements in performance were associated with an improvement in lifting technique.

Background

  • Action observation (AO) is learning a skill through observing another individual perform the same skill. AO is the most commonly used method of instruction in motor learning and has been shown to be a beneficial technique to facilitate learning of motor skills (Magill, 2007).
  • Two major theoretical concepts underpinning the success of AO on learning have been identified within behavioural literature:
  1. a) Visual perception theory (Scully & Newell, 1985); emphasizes how perceptual information picked up by the observer acts to constrain movement production and the importance of relative motion for learning through observation.
  2. b) Social learning theory (Bandura, 1977); proposes that information observed from the model is transformed into a reference of correctness for the observer to later compare their attempts at the skill. This theory also provides evidence that the type of model selected can influence the extent of learning.
  • Working with large groups of athletes is not uncommon for S&C coaches where teaching technical resistance training (RT) exercises can often be time consuming and unsafe especially when athlete to coach ratios within the gym are not favourable to teaching and supervising adequately.
  • S&C coaches understand the importance of good quality lifting technique for safety reasons and for reducing the likelihood of injury during RT. However the effects of good technique on performance improvements have rarely been quantified in an RT exercise learning/teaching studies.
  • The application of AO theory into S&C practices, specifically RT, of athletes could potentially assist S&C coaches in facilitating the learning of athletes in novel and technical exercises.

What we did

  • We recruited 15 participants (mean ± SD; age 20.9 ± 2.3 years, height 183.4 ± 8.4 cm, body mass 83.1 ± 6.4 kg) with no previous power clean experience.
  • Participants completed 12 training/testing sessions over a 4 week period and were asked to perform 3 sets of 5 repetitions of the power clean on each occasion.
  • Participants were split into two groups.
  1. Control (n=7) – who received verbal coaching cues and physical practice as is normal in S&C coaching, and;
  2. Experimental (n=8) – who received verbal coaching cues and physical practice (same as control group), but also observed video of a skilled model performing the power clean prior to them performing each set.
Figure 1. Participant from the Action Observation group watching vision of an expert model on a tablet computer (IPad 2, Apple).

Figure 1. Participant from the Action Observation group watching vision of an expert model on a tablet computer (IPad 2, Apple).


  • We analysed kinematic data from video recordings of participants performing the power clean who were fitted with joint centre markings during testing. We then transferred the video to a computer and were able to calculate joint angles using a specific computer program.
  • Kinetic data was also analysed and collected from a weightlifting analyser (Tendo unit) attached to the barbell.
  • A repeated measures study design was used with testing at pre-intervention, end of week 2, end of week 3 and post-intervention

What we found

  • Results showed faster improvements (3%) of power clean technique with AO facilitated learning in the first week (Fig. 2).
Figure 2.

Figure 2.


  • Performance improvements were associated (21.5%) with technique improvements (Fig. 3.)
Figure 3.

Figure 3.


Below I’ve included some comparison pictures of the expert model, AO group and control group in each phase of the power clean during the 4 week training study (see figures 4-8). These are only examples of individual members from each study group and not a representation of the entire cohort.

Figure 4. Start Position: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 4. Start Position: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 5. End of 1st Pull: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 5. End of 1st Pull: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 6. End of 2nd Pull – Most extended position: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 6. End of 2nd Pull – Most extended position: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 7. Catch Phase: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 7. Catch Phase: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 8. Absorption Phase – Deepest squat position: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.

Figure 8. Absorption Phase – Deepest squat position: Weekly power clean technique pictorial comparison between control group participant, AO group participant and the skilled model. PrT = Pre-Test, EW2 = End Week 2, EW3 = End Week 3 and PoT = Post-Test.


***Apologies for the relatively low image quality in figures 4-8.

The published version of the full study is available for download (click on image below for link).

Sakadjian, Panchuk & Pearce - Screenshot


In conclusion

  • AO combined with verbal coaching and physical practice of the power clean resulted in faster technique improvements.
  • The association presented in the current study suggests that correct technique should also be considered beneficial for improving the performance of the power clean exercise.
  • Potential limitation – the constant weight of the barbell throughout the training intervention. This may have been a contributing factor for the plateau seen in technique improvement for the AO group after initial improvement.

References

Bandura A. Self-efficacy: toward a unifying theory of behavioral change. Psychol Rev 84: 191, 1977

Magill RA. Motor learning and control: concepts and applications. New York: McGraw-Hill, 2007.

Scully DM and Newell KM. Observational learning and the acquisition of motor skills: Toward a visual perception perspective. J Hum Mov Stud 11: 169-186, 1985.

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The Inner Sanctum: Dan DiPasqua


Profile: Dan DiPasqua
Head Shot
Dan is currently the Head Strength Coach of the Melbourne Storm RLC. Previous to his current role, he was the Storm’s Assistant Strength and Conditioning Coach for over 5 years. Dan is also a strength and power coach at Elite Sports Performance gym where he also trains as a competitive powerlifter. He has a great passion for the sport of powerlifting which has led to a lot of time under the bar. Other strength and conditioning roles Dan has held include working with the Malaysian track cycling team and in the Victorian Football League (Australian Football). Along with his impressive and vast experience, Dan has an undergraduate degree in Exercise and Sport Science and has recently completed his Masters of Strength and Conditioning.

Tendinopathy – by Sean Docking

Sean’s lecture covered the latest evidence related to tendinopathy injuries. In great detail he covered the pathology of tendinopathy, imaging modalities for tendons and the effect load has on tendinopathy injuries.

Tendinopathy was previously and incorrectly referred to as tendinitis. This was incorrect as the “itis” part of “tendinitis” implies that the pathology associated with the injury is inflammation based. However, evidence has shown that this is not an inflammation based injury that can be effectively treated with rest, ice and anti-inflammatory drugs. The injury pathology has been shown to be as a result of tendon cell disruption and is now referred to as tendinopathy or tendinosis. Sean explained that this is a very common injury which can affect inactive individuals and the elite athletic population as well as both older and younger population groups. Furthermore, tendinopathy can be present in the various tendon structures of the body including the patella, achilles, adductor, hamstring, lateral elbow and supraspinatus of the rotator cuff group. Tendinopathy injuries are also more common than what may be reported in the literature, since the standardised definition on tendon injury is “missing training or competition”. This definition doesn’t represent the number of individuals who may have tendinopathy related pain but don’t miss training or competition. Associated risk factors for tendinopathy include age (especially Achilles), gender (more prevalent in males), genetic predisposition and a waist circumference of greater than 83cm.

The major clinical features of tendinopathy as stated by Sean include:

  • Focal localised pain
    • Pain doesn’t diffuse or refer to other areas
  • Pain is load dependant
    • Increase in load = increase pain
  • Pain is generally worse the day after loading

Normal tendons have four major features:

  1. Flat elongated tenocytes (tendon cells)
  2. Parallel collagen fibres
  3. Small proteoglycans (molecules which attract water into tendon)
  4. Minimal blood vessels and nerves

These are the opposite in tendons that are abnormal in structure. The abnormal tendon features include:

  1. Activated and round tenocytes (tendon cells)
  2. Loss of collagen architecture (no parallel alignment)
  3. Large proteoglycans (more water into tendon creating tendon thickening)
  4. Increased presence of blood vessels and nerves in tendon

Sean then nicely presented how the evidence shows that there is a sequence of histopatholgical change that occurs within tendons. Stage one is where the tenocytes become increasingly active and rounded. Stage two involves an increase in proteoglycans size. Proteoglycans encourage water to enter the tendon which causes tendon thickening and collagen disruption. Collagen disruption occurs in the final stages of pathological tendon change. However, this can’t occur without changes in tenocytes and proteoglycans. Sean then spoke of the continuum of tendon pathology severity and how tendons can drift between within this continuum (see figure 1).

Continuum of tendon pathology

The stages within the tendon pathology severity include:

  • Reactive tendon: tenocytes are activated and increased with an increase in proteoglycans also. Importantly, the collagen fibres are still in a parallel aligned structure. A normal tendon moves into this reactive phase as a result of excessive overloading. With appropriate load management a reactive tendon can return back to normal.
  • Tendon disrepair: in this stage tenocytes are still activated and increased as are the proteoglycans. The increased water in the tendon from the proteoglycans start to disrupt the structure of collagen and the parallel alignment becomes compromised. Tendon disrepair occurs if a reactive tendon continues to be excessively loaded. If the collagen disruption is not overly significant, there is the possibility of returning the tendon back to normal. However, the greater collagen disruption that has occurred means it becomes increasingly more difficult to return back to normal tendon structure.
  • Degenerative tendinopathy: this stage is where cell (tenocyte) death occurs, collagen is severely disrupted away from the parallel alignment and blood vessels and nerves begin to infiltrate the tendon. A tendon will enter this degenerative phase if it is excessively loaded in the previous stages. It is extremely difficult to return the tendon to normal structure once in this phase, however with adequate rehabilitation and load management the tendon can be asymptomatic.

Once again, this is a continuum which means tendon pathology status could potentially sit in-between phases. For example, tendon pathology may sit between the reactive tendon phase and the tendon disrepair phase.

Sean then moved onto discussing the tendon imaging methodologies available and the benefits and limitations associated with them. Traditionally, ultrasound and magnetic resonance imaging (MRI) have been the most commonly used imaging methods. These methods have been reported within the literature as having good to excellent accuracy and sensitivity for detecting clinical tendinopathy. However, limitations associated with ultrasound are that they are highly user dependant. Ultrasound imaging quality can be affected by the quality of the radiographer since image artefacts can be created with a transducer tilt of only ~5°. This can affect diagnosis accuracy. Further limitations of ultrasound and MRI include that these methods are reliant on subjective interpretation for important features such as categorising tendon thickness, grading the severity of tendon pathology and tracking tendon changes over time. A more contemporary method of imaging tendons is the use of ultrasound tissue characterisation (UCT) which was initially developed for use on horses. UCT allows for reliable quantification of tendon structure. A normal ultrasound probe is pulled over the length of the tendon on a motorised track capturing 600 transverse images over a 12cm length. This provides a 3 dimensional image of the tendon. Benefits of UCT include standardisation of transducer tilt angle, frontal/sagital/transverse (3D) images of tendon and the comparison of repeat tendon scans over time. The quantification of tendon structure from UCT scans comes from the level of relative image pixel brightness detected by the imaging device. The output of the UCT scan consists of 4 colours which each represent a different level of tendon structure status/damage (see figure 2).

Figure 2

Sean discussed that UTC has been a useful tool for quantifying/staging where on the tendon pathological continuum a particular tendon sits. Figure 3 below shows the relationship between a UTC scan of an Achilles tendon and the tendon pathology continuum discussed earlier.

Figure 3

Since load is a major factor in tendinopathy injury, Sean discussed what load actually is specific to tendons. He discussed load in terms of the intensity of stimulus which is based on the stretch-shortening cycle:

  • Low tendon load: tendon stretches slowly without much recoil (e.g. strength training and cycling)
  • Medium tendon load: tendon stretches and is required to recoil (e.g. straight line running – not maximal speed and power training)
  • High tendon load: tendon is required to undergo significant stretch and recoil at speed (plyometrics, agility and change of direction at high speeds)

When attempting to manage symptomatic tendinopathy, the aim is to maintain some level of tendon loading with low or medium load while minimising the amount of high tendon loading. It is important to keep load in tendons to avoid losing or diminishing tendon capacity which may prove to be problematic when re-loading commences.

I found this lecture by Sean extremely interesting and informative. This was the first time I had heard about the imaging technique of UTC in such detail, and I am really interested in what future knowledge may be gained with this technology. The information Sean presented on the histopathology of tendons was also great.

Profile: Sean Docking

Sean Docking

Sean Docking, is physiotherapist and is in the final stages of his PhD studies in the Department of Physiotherapy at Monash University. His PhD research involves the use of Ultrasound Tissue Characterisation (UTC), a new and novel technique that allows measurement of subtle changes in tendon structure that are not detectable using conventional imaging techniques. He has also worked at Carlton football club (AFL).

Prevention of Groin Injuries in Sports – by Dr Kristian Thorborg

Dr Kristian Thorborg, a world leading sports physiotherapist and researcher on groin injuries in athletes, delivered a great lecture on prevention of groin injuries in sports.

A common theme from groin injury experts and within the literature is that the source of groin injuries are quiet difficult to differentiate between. This is largely due to the complex anatomical structures and kinesiology surrounding the area. Dr Thorborg discussed 4 clinical entities related to groin pain and how common each of these are:
1. Adductor related groin pain (50-70% of cases)
2. Abdominal related groin pain (5-20% of cases)
3. Psoas related groin pain (10-20% of cases)
4. Hip related groin pain (5-10% of cases)

Even though the underlying pathology is difficult to assess, the evidence suggests that categorising groin pain into these 4 entities can be achieved reliably from a clinical assessment. Adductor related groin pain is most common in athletes of team sports, while psoas related groin pain is most commonly seen in runners.

As mentioned earlier, the difficulties associated with examination of groin pain are related to the intricate musculoskeletal make-up of the hip-adductor-abdominal complex. Dr Thorborg explained that the rectus abdominis, gracilis and the adductor longus muscles insert on the same aponeurotic plate in front of the pubic symphasis while they also share some interdigitating muscle fibres. Furthermore, the pubic symphasis and joint capsule are other sources of potential groin pain that need to be considered throughout clinical assessment. He also spoke of an interconnected system made up of anterior muscle synergis (transverse abdominis, internal and external oblique, rectus abdominis and the pubic symphasis structure, etc), posterior muscle synergis (latissimus dorsi and the gluteus maximus, etc) and finally, the medial-lateral muscle synergis (gluteus medius, the adductors including the large adductor magnus). This theory of interconnected muscle synergis is extremely important for force dissipation and to maintain pelvic stability. Anatomical considerations such as these are reasons why it is difficult to pin point the source of groin pain. Previously, groin pain injuries were often incorrectly reported as being sports hernias. This was an incorrect diagnosis as there was not actually a hernia present and the issue was more related to the inguinal canal. The diagnosis of inguinal canal related groin pain is not all that common, however it does exist. The inguinal canal related groin pain falls into the category of abdominal related groin pain in the 4 clinical entities system discussed by Dr Thorborg. Both adductor and abdominal related groin pain are the most common entities seen in team sport, of which abdominal related groin pain is less frequent but has an increased rehabilitation duration.

Since the adductor and abdominal related entities are the most common in team sports, the remainder of Dr Thorborg’s lecture was focussed on these entities of groin pain. The majority of research work done by Dr Thorborg has been in ice hockey and soccer athletes. Evidence suggests that risk factors that may have an association with sustaining a future groin injury include; previous groin injury, weaker (<0.8) adductor to abductor strength ratio and decreased strength of adductor muscles. Recently, Dr Thorborg and colleagues found that isometric hip adduction strength testing of athletes was unable to differentiate those with groin pain and those without groin pain (control). However, they reported that there was a statistically significant 20% reduction in eccentric hip adduction strength between those with groin pain and the control group. A potential explanation for why this may be the case is that eccentric contractions are more specific to team sport athletic movements than what isometric contractions are. The assessment of adductor strength is either usually tested through a bilateral isometric groin squeeze test which can be done at various knee and hip angles (figure A) or unilaterally with a hand held dynamometer test (figure B). According to Dr Thorborg, the protocol of groin strength testing used within the evidence should be an important consideration when reading groin injury literature.

Unilateral Adduction Strength Dyno

Fig. A

Bilateral groin squeeze 2

Fig. B

 

In relation to sports performance, groin pain symptoms appear to be commonly reported during explosive movements such as side-cutting and in the adductors of the kicking leg for kicking sports such as soccer. Dr Thorborg nicely summarised the evidence which suggests that eccentric hip power and hip adduction and abduction moments are not related to side-cutting performance. In fact the role of the adductors and abductors during side-cutting and hopping movements is to provide hip stability rather than producing mechanical power. Dr Thorborg then discussed injury prevention related to groin injuries. He suggested that careful monitoring of load and overload is important while preparing athletes for specific and repetitive loads is also critical. Dr Thorborg stated that injury prevention programs directed towards groin injuries is an area that is largely under-studied within the literature. There is only one randomised control trial with a primary aim of groin injuries in the current literature (Hölmich et al, 2010) and therefore greater future research in this area is required.

Holmich et al (2010)

Common groin injury prevention exercises include isometric adductor squeezes, adductor and abductor resistance band exercises, abdominal strength exercises and exercises aimed at improving balance and coordination around the hip. The general critique of commonly used groin injury prevention exercises is that they may not be specific or intense enough to elicit strength gains, leading to electromyography studies investigating the level of muscle activation within these exercises. Conventional resistance training and the known strength adaptations that are elicited from this method of training are also thought to be quiet beneficial for groin injury prevention. Dr Thorborg stated the importance of including eccentric based work for adductors, abductors and the abdominals in injury prevention programs.

In finishing, Dr Thorborg spoke of how the classification of a groin injuries for inclusion in studies can be somewhat misleading in terms of how many players are actually suffering from groin pain. In order to be classified as having a groin injury, the athlete must have missed a training session or competitive match. However, Dr Thorborg says that there are many players (50%) who train and compete while having some form of groin pain but aren’t counted as having a groin injury since they continue to train and play. He states that groin injury prevention programs and interventions are still required by these athletes.

This lecture was again a fantastic opportunity to learn from another one of the world’s top practitioners and prominent researchers specific to athletic groin injuries.

Profile: Dr Kristian Thorborg

Thorborg
Dr Thorborg is an Associate Professor at Copenhagen University in Denmark, and is a Specialist in Sports physiotherapy. He completed his Masters in sports physiotherapy at Melbourne University (Australia) in 2003. In 2011 he then went on to receive his PhD from Copenhagen University which investigated “Clinical Outcome Measures in Physically Active Individuals with Hip and Groin Pain”. Dr Thorborg has been lecturing at the Copenhagen University since 2009, and is an invited speaker at national and international conferences. Professional sporting clubs regularly seek out his expertise as a consultant.

Prof. Tim Noakes visits Melbourne FC

We were very fortunate to have world renowned professor of exercise and sport science Dr Tim Noakes come to the Melbourne football club and present to the athletes on topics related to high performance sport. I have included a number of pictures from the talk by Dr Noakes (click on images to make larger).

Dr Noakes began by providing a timeline of his academic career to date which has been based largely around ‘challenging beliefs’. This approach has made him a controversial figure in the views of many. Since there are two sides to every story/argument, Dr Noakes says he is not controversial and that he is merely presenting and educating on both sides of the argument.

photo 1 - Copy

The first topical area he covered was related to hydration and performance. This was an area Dr Noakes became interested in researching after coming across initial data (very low blood sodium concentrations) from cases of perfectly healthy individuals dying or being admitted to hospital during/after prolonged exercise (i.e. marathon running). This developed into many research projects and even a book publication (Waterlogged) whereby the hydration guidelines for endurance sport athletes were rewritten. Dr Noakes reported that these individuals had died or become ill from essentially waterlogging their body’s and suffered from the little known (at the time) medical condition of exercise induced hyponatremia. A major contributing factor for hyponatremia according to Dr Noakes was the commercialization of sports drinks and the marketing of these products with poor, and in some cases non-existent science to support their claims. Dr Noakes encourages athletes of prolonged duration exercise to drink to ‘thirst’ and not beyond that, as this is the humans’ evolutionary mechanism of indicating the need for fluid intake. He said becoming dehydrated to the extent that modern runners usually do, carries no documented medical risk and will likely only leave the athlete feeling a bit thirsty and have a dry mouth. According to Dr Noakes, the body is adapted for conditions of mild dehydration. Dr Noakes agrees that true dehydration can be detrimental to performance, however the amount of focus and the ongoing recommendations that athletes should chronically be drinking fluids is not the answer. The large majority of his research done in this area is on endurance based athletes and therefore should be taken with caution when considering hydration prescription for other athletes. Furthermore, all athletes should have individualised nutrition and hydration plans according to their needs.

Moving on from his early career research on hydration, Dr Noakes shared his research findings on ‘fatigue’ and its relationship to athletic performance. He became interested in this area when he contemplated the question of how elite level athletes can win or lose by millimetres or milliseconds. The primary notion as to why the athlete would come second by such a small margin was thought to be that the athletes’ muscles regulate exercise performance. That is, the presence of metabolic by products such as lactate, are increased as a result of the heart being unable to meet the oxygen demands of the muscles. Dr Noakes states that this model or thinking of what causes muscle fatigue is flawed since it doesn’t take into account the role of the brain and factors such as motivation. He used an example of pacing strategy research of Haille Gebrsellasie’s 1998 world record run in the 10km event to dispel that idea of muscles being the sole regulator of performance. Dr Noakes illustrated the breakdown of running pace per km during the 10km record run with the final km of the run being done at the fastest running speed throughout the entire 10km race.

photo 2 - Copy

From this, he poses the question of how is it possible to be running the fastest at the end of the race when the athlete is most fatigued? Dr Noakes consequently suggests that fatigue has little to do with the physical state of the body, since the athlete has been able to perform at the highest intensity when his muscles are the most tired. He goes on to suggest that fatigue is just an emotion called upon by the brain to prevent damage to the body during exercise. This subsequently led to Dr Noakes developing the central governor of exercise model (see image below) which is based on the feed forward/feedback system between the brain and muscles. Initially, this model was heavily criticised but is now more widely accepted as a potential contributor to fatigue and athletic performance. As mentioned earlier, this model proposes that it is the brain that dictates exercise intensity and duration in order to ensure its own survival. He proposes that individuals always have more to give from a physical capacity and information related to exercise task, such as duration or length of competition, can help determine a pacing strategy. Dr Noakes discussed that athletes would select different performance strategies with knowledge of the end point of exercises bouts (i.e. 2 minutes versus 20 minutes). Other motivational factors that can influence performance include the presence of other competitors and the athletes self belief. The power of the brain directed by the individuals’ beliefs, self talk and mindset may therefore be able to override the emotion and physical feelings of fatigue. Dr Noakes suggests that these qualities are all trainable and may be the millimetre or millisecond difference between first and second place.

Noakes Central Governor Model

The final part of the presentation by Dr Noakes covered his most recent and probably the most controversial of his research topics regarding the contemporary science of low carbohydrate high fat (LCHF) diet. A personal experience with his own health that was related to a family history of type 2 diabetes initiated his research interest into this way of eating. He emphaises that this is not a ‘diet’ and is a long term way of eating. Dr Noakes states the roots of where it all went wrong was in 1959 when a USA researcher made links, through poor science and data manipulation, between high fat diets being the cause of heart disease. As a result, the USA senate recommendations in 1977 suggested that fats are evil and more carbohydrates should be consumed and pushed this way of thinking to the mass population. These recommendations were once again made with little or poor quality scientific basis according to Dr Noakes. From that period onwards, obesity rates and medical issues such as heart disease, high cholesterol and type 2 diabetes became more prevalent and therefore instigated further research into the link between diet and the rise in these medical issues. Delving into the research available on high fat diets, Dr Noakes found no sound evidence that this method of eating is linked to heart disease. In fact he discussed that the common French diet is a high fat diet and the French population have low rates of heart disease. According to Dr Noakes the current evidence on LCHF diet is irrefutable for general health benefits, weight control and for the treatment of the medical issues mentioned earlier. He also believes that the science related to LCHF for prolonged exercise performance is very strong. Carbohydrate resistant individuals are relatively ineffective in using carbohydrates as a fuel source, therefore the LCHF method of eating will unlikely be detrimental to exercise performance. Dr Noakes discussed and very strongly advised that processed foods, wheats, grains and sugars should all be avoided. He states that pasture raised real foods (unprocessed) that humans have been eating for over 2 million years such as meats (with fat), eggs and leafy greens that grow above the ground are what should be consumed. The athletic performance benefits in relation to LCHF shown by Dr Noakes, are once again in endurance and ultra-endurance athletes. More research is required on the effects of LCHF on intermittent high intensity based athletic performance.

photo 3 - Copy

This was a truly insightful presentation from one of the leading academics in sport science and medicine. The Melbourne FC athletes and staff were very grateful of Dr Noakes sharing his wisdom and time. As someone that has read a lot of his work in the scientific literature, I was personally delighted at the opportunity to meet him. It’s also great that the Melbourne FC has a new supporter!

photo 5

 

Profile: Dr Tim Noakes

 Noakes

Dr Noakes is a South African professor of exercise and sports science at the University of Cape Town and is also a trained medical doctor. He is the author or co-author of more than 500 scientific publications in peer reviewed journals and has more than 14000 citations. He is also the co-founder and executive co-director of the Sports Science Institute of South Africa. Dr Noakes has run more than 70 marathons and ultra-marathons and is the author of several books on exercise and diet which include; Lore of Running, Challenging Beliefs, Waterlogged and the Real Meal Revolution.

The Inner Sanctum: David Misson

 

Profile: David Misson

David Misson is currently the Elite Performance Manager of the Melbourne Football Club, a role he has been in since the end of 2011. Prior to joining Melbourne FC, he was the Elite Performance Manager at St.Kilda FC for four seasons (2007-2011). Dave was previously with Sydney Swans from 2001-07 and was a key figure in the Swans’ 2005 premiership campaign. Previous to his role at the Swans, Misson was fitness advisor with the Australian national cricket team from 1998-2000. He has also worked with elite sporting teams including the Wallabies, Waratahs, Cricket NSW, North Sydney Bears, Tennis Australia, NSWIS track and field and Sydney Swifts.

Anterior Cruciate Ligament Injury – By Ben Serpell

In this lecture, Ben gave an insight into his experience as a rehabilitation practitioner and current researcher (PhD) on anterior cruciate ligament injuries. The presentation covered areas including knee anatomy and kinematics, risk factors, mechanisms, surgical repair, prevention and rehabilitation/return to play.

Ben discussed the amount of research that has been done on ACL injuries over the years and how the prevalence of ACL injury has remained relatively similar during that period despite all the research. This was a catalyst in his interest in researching ACL injuries and looking for what may be missing in the literature to decrease the prevalence of ACL injury. His PhD research is looking into the relationship between developing dynamic stiffness (around the knee joint) through methods such as plyometric training and its potential effect on reducing ACL injury. Genetics, ground/surface friction and skill level are all risk factors that have been reported within the literature to increase an individual’s likelihood of obtaining an ACL injury. Females have been reported to have a 6-fold increased risk of sustaining an ACL injury. These risk factors have been known and well established within the research for a long time, however ACL injury’s still continue to be sustained at an unchanged rate.

ACL injuries in high performance sport occur during contact and non-contact situations. When discussing the primary mechanisms related to ACL injury, Ben referred to the literature suggesting that 70% of ACL injuries occur during non-contact situations which are obviously more preventable than contact based ACL injuries. ACL injuries, whether contact or non-contact, occur with low knee flexion, rotation at the knee or a valgus moment at the knee. Typically these kinematics’ are seen during cutting actions, especially with the cutting movement being performed with a straight leg (low knee flexion) and foot planted outside the body’s centre of mass. This change of direction movement is more common with the “power cut” (figure 1) where changing direction to the left occurs off the right leg (contralateral direction to stance leg) as opposed to the “speed cut” (figure 2) where changing direction to the left occurs off the left leg (ipsilateral direction to stance leg).

power cut

Figure 1. Power Cut

speed cut

Figure 2. Speed Cut

Also, since one of the major functions of the ACL is to limit anterior translation of the tibia in relation to the femur, any movements where this occurs excessively will cause great stress to the ACL. Movements such as jumping and landing with low knee flexion (knee hyperextension) is a scenario where tibial anterior translation in reference to the femur occurs and when combined with high ground reaction forces during landing outside the centre of mass or with rotation then the ACL is in a very vulnerable position. This mechanism has been common in ACL injury in Australian footballers.

Understanding the anatomy, kinematics, risk factors and mechanisms of ACL injuries are important aspects to devising and implementing prevention strategies/programs. Ben discussed using methods such as plyometric training or sand/uneven surface running in order to develop pre-tension/co-activation and therefore have dynamic stiffness at the knee joint. This dynamic stiffness decreases strain on the ACL ligament during the primary injury mechanisms discussed earlier. He also stressed the importance of hip control as well as hamstring and core strength/activation (more globally known as the posterior chain). Expanding on his reference to hip control, Ben stressed the importance of the musculature around the hip joint being strong in both the sagital and rotational planes of movement as well as having a motor learning aspect within force reduction training with jump-land exercises. Another injury prevention method Ben spoke of was in reference to learning’s he’s taken from Frans Bosch whereby the technical components behind change of direction movements should be considered similar to straight line running. This may sound somewhat odd, but Ben explained that during change of direction cutting movements the aim should be to have foot plant occur as close to under the body’s centre of mass as possible, similar to foot strike during straight line running. He went on to state that during change of direction the shoulders should shift simultaneously to making the cutting movement as opposed to before, as this will reduce the rotational forces acting on the plant foot/leg. Therefore, coaching athletes to have sound straight line running mechanics may in fact have positive translation to change of direction mechanics in reference to reducing ACL risk. Ben also touched on proprioceptive work as an ACL injury prevention method and how he remains sceptical of this approach due to being of the belief that the likely major contributing factor for incorrect plant foot placement being hip control as opposed to proprioceptive deficiencies of the ankle.

Having the best possible ACL injury prevention program doesn’t guarantee that ACL injuries will be totally avoided, therefore rehabilitation protocols following injury must be considered. Ben talked about how injuries must be considered on an individual basis as the pathology, mechanism and type of surgical repair are all significant in devising rehabilitation programs. It’s not uncommon for the medial co-lateral ligament (MCL) or medial meniscus to also sustain damage during ACL injuries and if this is the case then these injuries can’t be ignored during rehabilitation. ACL reconstruction surgery generally entails using a graft from either the patella tendon or the medial hamstring tendon. This is also a critical consideration during rehabilitation, especially the different potential future injury risks these two surgical options may present. Ben doesn’t personally have a preference as to which type of graft is used to reconstruct the ACL, however he strongly advocates that hamstring strength is the same and even greater than pre-injury levels before return to play is considered. Interestingly, Ben mentioned some work he has been involved with relating to increasing the stiffness in the ligament graft through dietary changes during the phase of religamentisation (up to the 12 week mark). Ben stressed that the biggest “danger period” is between the 6-10 week mark post surgery as this is the most vulnerable period for the new graft. In terms of exercise progressions, the following is a general indication of some of Ben’s key rehabilitation milestones:

  • 6-10 weeks: low level strength work and range of motion work is completed.
  • 10-12 weeks: pool running (1.2m depth) including running drills plus low level drills on gymnastic floor. Must aim to achieve full extension in period prior to over-ground running.
  • 12-14 weeks: over-ground running in straight line for 4 weeks (approx.) plus supplement multi-directional work in the gym/gymnastic floor
  • 16-18 weeks: multi-directional over-ground running.

The following phases to the above includes progressing into sport specific functional training followed by full contact training while ensuring the athlete feels confident when performing these training demands. Throughout the rehabilitation process, the progression of functional strength is critical. This is particularly important for hamstring strength if the ACL graft site was taken from the hamstring, especially when research suggests that it can take between 12-18 months before eccentric hamstring strength returns to pre-surgical levels.

Ongoing strength work for the musculature around the hip complex is critical once return to play has been achieved as there are multiple secondary injuries which can arise if asymmetries are not addressed.

This was a great lecture/presentation from Ben who is well versed in the practical programming and rehabilitation of ACL injury while also being at the cutting edge of the ACL injury research as he nears completion of his PhD.

If you want any further reading regarding ACL injury, Ben published a great review paper in the Journal of Strength and Conditioning Research in 2012 (see below). Look it up online.

Serpell 2012

Profile: Ben Serpell

Ben Serpell

Ben is currently the Athletic Performance Coach at the ACT Brumbies (SuperRugby) and is a PhD Candidate at Australian National University in ACL injuries. He has previously worked as a strength and conditioning coach in the AFL and abroad in the United Kingdom. He is also accredited as a level 2 strength and conditioning coach by the Australian Strength and Conditioning Association.

Load Monitoring

Dr Burgess’s lecture got me to thinking about some of the load monitoring protocols/methods that I have used in the past or use currently. Here is a list of these protocols/methods with some evidence to justify their use.

Musculoskeletal Screening

The ability to predict injury is a common goal sought by sport science and medicine staff. Musculoskeletal screening of athletes has been a common method studied within the research for providing a means of predicting injury occurrence and areas of weakness/deficiency (Gabbe et al., 2004; Dennis et al., 2008; Dallinga et al., 2012).

Heart Rate Recovery (Polar Team System)

A weekly sub-maximal HR recovery test conducted 2 days post competition. The protocol used is the one recommended by Buchheit et al. (2007) where athletes complete a 5 minute continuous sub-maximal run at 9 km/h-1 (2.5 m/s) followed by a 1 minute passive rest period. A HR recovery test such as this provides the sport science staff with an indication of physiological recovery and more specifically a state of the athlete’s cardiac autonomic activity (Buchheit et al., 2007).

GPS

Total distance (Castellano et al., 2011), time spent in high intensity running zones and high intensity movements (accel + decel; Varley et al., 2012) are accurate GPS variables with 10hz devices. However, extra caution should be taken during analysis of high intensity movement GPS data as the accuracy of this parameter is diminished with increased movement velocity (Akenhead et al., 2013). These are a few of the GPS variables that we use to monitor load, stress and fatigue from training and matches. With a database of historical GPS data to compare with, we look for concerning trends or large changes from an athlete’s normal performance output.

Countermovement Jump (on force plate)

It has been suggested that low frequency neuromuscular fatigue is an important variable to monitor for elite athletes (Fowles, 2006). Cormack et al., (2008a & 2008b) showed that the ratio between flight time and contraction time during a single countermovement jump was able to validly and reliably represent delayed neuromuscular recovery in elite team sport athletes (Australian footballers). The flight time to contraction time ratio is reliably measured by the FitTech 400s force plate (Cormack et al., 2008c).

 

General Comments on Load Monitoring

I have used or currently do use multiple other methods including daily wellness questionnaires and session rating of perceived exertion. I think athlete monitoring should be a multi-factorial approach directed by evidence based research. Considering athlete monitoring methods as being pieces of a puzzle is a way I like to bring all these methods together. For example, if we have an athlete flag on only one monitoring variable out of the numerous ones we use then we would follow this up further but it doesn’t necessarily mean that we will reduce that athlete’s load or intervene. However, if we start getting flags for a certain athlete on a few different monitoring variables then we look to investigate this further and it usually results in an intervention of some sort (this is dependant according to what that flag/issue is).

The worst mistake that we as high performance practitioners can make is to attempt to take all these methods and the data that we get from them and try to combine them into one number (“the magic number”) that we think will give us a valid and reliable indication of an athlete’s recovery/wellbeing status.

References

Akenhead R, French D, Thompson KG, et al. (2013) The acceleration dependent validity and reliability of 10Hz GPS. Journal of Science and Medicine in Sport.

Buchheit M, Papelier Y, Laursen PB, et al. (2007) Noninvasive assessment of cardiac parasympathetic function: post exercise heart rate recovery or heart rate variability? American Journal of Physiology-Heart and Circulatory Physiology 293: H8-H10.

Castellano, J., Casamichana, D., Calleja-González, J., San Román, J., & Ostojic, S. M. (2011). Reliability and accuracy of 10 Hz GPS devices for short-distance exercise. Journal of sports science & medicine, 10(1), 233.

Cormack SJ, Newton RU and McGuigan MR. (2008a) Neuromuscular and endocrine responses of elite players to an Australian rules football match. International Journal of Sports Physiology & Performance 3: 359-374.

Cormack SJ, Newton RU, McGuigan MR, et al. (2008b) Neuromuscular and endocrine responses of elite players during an Australian rules football season. International Journal of Sports Physiology & Performance 3: 439-453.

Cormack SJ, Newton RU, McGuigan MR, et al. (2008c) Reliability of measures obtained during single and repeated countermovement jumps. International Journal of Sports Physiology & Performance 3: 131-144.

Dallinga JM, Benjaminse A and Lemmink KA. (2012) Which Screening Tools Can Predict Injury to the Lower Extremities in Team Sports? Sports Medicine 42: 791-815.

Dennis RJ, Finch CF, Elliott BC, et al. (2008) The reliability of musculoskeletal screening tests used in cricket. Physical Therapy in Sport 9: 25-33.

Fowles JR. (2006) Technical issues in quantifying low-frequency fatigue in athletes. International Journal of Sports Physiology and Performance 1: 169.

Gabbe B J, Bennell KL, Wajswelner H and Finch CF. (2004) Reliability of common lower extremity musculoskeletal screening tests. Physical Therapy in Sport 5:90-97.

Varley MC, Fairweather IH and Aughey1, Robert J. (2012) Validity and reliability of GPS for measuring instantaneous velocity during acceleration, deceleration, and constant motion. Journal of sports sciences 30: 121-127.

Load Monitoring as an Injury Prevention Tool – By Dr Darren Burgess

In this lecture, Dr Burgess discussed some of the load monitoring tools and screening processes that he has used over the years in elite soccer (English Premier League – EPL) and Australian football (AFL) to help predict injury, especially soft tissue injury.

Dr Burgess commenced by comparing the average load demands of AFL athletes as opposed to EPL athletes. Interestingly, he stated that even though the EPL athletes were subjected to greater loads, there were no greater rates of injury between EPL and AFL athletes. Being at one of the biggest clubs in European soccer (Liverpool FC) had a big impact on common and well accepted exercise prescription principles. Dr Burgess discussed some of the programming consideration that they had to take into account due to their hectic playing schedule where in some weeks they would play 3 matches, were required to travel and only had 3 days between matches. He spoke about the lack of evidence base regarding how to train athletes with this type of schedule and therefore had to rely on common sense as opposed to the evidence. Other programming considerations included; language and cultural barriers with athletes and coaches, international travel, screening protocols to help guide the program and placing significant consideration on individual athlete training history.

Dr Burgess then outlined the screening process they had in place, with athletes being screened with a modified Functional Movement Screen (FMS) and a musculoskeletal screening weekly and/or 48 hours post every match. The screening tests that they used were systematically chosen by the medical department with strong evidence from the literature supporting each tests validity and reliability. In addition to musculoskeletal and FMS screenings, they collected creatine kinase data as a marker of muscle damage, the OptoJump system to measure athletes flight time to contraction time ratio as a test for neuromuscular fatigue, isokinetic dynamometry testing for muscle strength and heart rate variability monitoring for a marker of athlete stress (internal load). In conjunction with these objective monitoring tools, they also used wellness questionnaires as a means of subjective monitoring. Dr Burgess also described some statistical methods used to analyse their data. He spoke of comparing individual athletes relative to their own average results as opposed to comparing with other athletes or just simply looking at the raw values. He also outlined the importance of having an understanding of each tests smallest worthwhile change.

Interestingly, Dr Burgess stated how different the gym training culture is compared to the structured and vigilant place this form of training has within Australian football programs. He described the variable nature of the gym training programs in elite European soccer which were dependant largely on player needs, time of season, rehabilitation status, pre-season/competition schedule and the barriers faced when attempting to devise a well periodised strength program. He stressed the importance of having a periodised plan for training prescription rather than flying off the cuff and highlighted the highly popular weekly training load periodisation structure that nearly all European soccer clubs follow (see below).

Screenshot 2014-08-11 18.36.34.png

Monitoring training sessions with GPS tracking devices and heart rate monitors allowed the high performance staff to collect  data from each training session and get an indication of each athlete’s fitness status. This data was also used as part of the athlete monitoring process for injury prediction.

Dr Burgess finished off the presentation by outlining a few alternate methods to help with indentifying increased injury risk. He discussed using aspects of a fatigue and fitness model theory originally developed by Bannister and Calvert (1975), whereby the interaction between fitness, fatigue and performance is modelled. From a model such as this, you can analyse team data and identify any outliers in any of the three areas of fatigue, fitness and performance. Another method to potentially assess injury risk is through the use of a neural network. This is a mathematical system approach which uses multiple data inputs to provide an alert of potential injury risk from retrospective data combinations that have previously lead to injury. However, this type of system can be quiet costly.

In summary, this lecture on “Load Monitoring as an Injury Prevention Tool” by Dr Burgess was highly insightful with a lot of applied examples. It was great that Dr Burgess was kind enough to share such information from his work with world class team sport athletes.

In line with Dr Burgess’s lecture, my next blog post will discuss some of the athlete load monitoring protocols/methods I use currently or have used in the past. Be sure to click back to Elite Performance Science shortly.

 

Profile: Darren Burgess, PhD

Burgess

Darren is currently High Performance Manager at Port Adelaide Football Club (AFL) having returned to Australia in November 2012 to take on this role. Prior to this appointment Darren was Head of Fitness and Conditioning at Liverpool Football Club (EPL), having started with the club immediately after the 2010 Football World Cup. From 2008 to 2010 Darren was the Head of Sports Science for Football Federation Australia as well as the Australian Socceroos Fitness Coach. Darren has previously worked as Head of High Performance at Port Adelaide Football Club (2004-2007) and assistant fitness coach with Sydney Swans in the AFL (1997-2000), as well as head fitness coach with the Parramatta Power in the Australian National Soccer League (2002-2004). Darren has also worked as a video analyst with the Australian Olympic Soccer Team prior to the 2004 Athens Olympics. Dr Burgess completed his PhD in movement analysis of AFL and Soccer in 2012.

Expert Lecture Review Series

As part of the Masters of High Performance Sport degree (from ACU) that I am currently studying, I have the opportunity to be furthering my education through world renowned experts. As a result, I will be sharing some of this information on my blog in the form of a series titled “Expert Lecture Reviews”.

A review of a presentation/lecture given by Dr Darren Burgess on “Load Monitoring as an Injury Prevention Tool” will be the first Expert Lecture Review in the series and will be posted in the coming days.