Framework Building for Hamstring Training – Part 1


Scientific Argument:

Question: What tools can we use to aid in making better decisions for training of the athlete with a goal of mitigating injury

Claim: A Framework ( or list of assumptions) combined with a process of integration and evaluation along with a resource aimed at filtering human faults in decision making is a powerful solution and/or training tool for mitigating injury.


  1. Historical and current use of the OODA Loop
  2. Current developments of Artificial intelligence in Sports industry for decision making

Potential Fallacies/Heuristics in this Argument: False Analogy, Data Mining, Confirmation Bias.



This post and story of process building aims to tackle a complex issue prevalent in sports today.  I will make claims in this post that have scientific support but at the moment cannot be considered to be strong evidence – or evidence at all. Nonetheless, the objective of this writing piece is to demonstrate a process and make aware potential resources to aid decision making in the training environment.



Framework Building for Hamstring Training – Part 1

When I think of an athlete doing a Swiss ball curl, part of me  begins to cringe. It’s a bit like S&C PTSD and If you’re a movement specialist of any sort, you can likely empathize with the notion that certain exercise can elicit more than physical stress, they can also bring about anxiety.  The Swiss ball Leg Curl, alone is a decent exercise that requires a degree of pelvic stabilization, coordination and strength to be performed optimally. Thus, it isn’t fair to say that i dislike the exercise. However, the experience of watching a team of athletes perform said exercise brings a level of dissatisfaction that forces me back to the program design drawing board. The experience of dissatisfaction with a relatively simple operation in any growing system is common. Often, dissatisfaction forces system to reevaluate rather than carry on with a similar operating system. Good systems learn and perform updates and annoyingly request periods to restart the system to issue the update.

     In the field of Strength Training and Conditioning updates exist in various forms and generally include research publications, presentations and training forums that provide the avenue for system growth and reevaluation. In addition, our operating systems utilize relevant experience to continue to provide the agency to make edits for smooth satisfactory training experiences. This process of learning, experiencing, testing, editing, dismissing, reevaluating is fundamental not only to Strength Trainers but to Systems. This process can be described more succinctly through the OODA Loop, a cycle developed by the Military with a degree of Universal Use.  The OODA Loop can’t be used just on it’s own, we need to record our lessons in observation, Orientation, Act and decision Making in order to keep that cycle moving. This is where the importance of a framework comes into play. Thus through this OODA Loop process, and framework we can gain understanding as to my perspective with hamstring training and ultimately the dissatisfaction with the Swiss ball leg curl.

   It is important to share that the OODA Loop never stops as long as the system goes on Slide1and neither does framework building.  Our learned experiences must be combined with experience and tested against  the changing landscape of perspective and environment. It needs to be tested and retested with an implicit understanding that changes and/or growth is a likely property. 

   It’s here that i’d like to share my insight to this process of learning, reaching and gain perspective for Hamstring Training. The value of framework building is useful for anyone looking to build or operate a system.

Step 1: Explain your why

The first and most necessary step is to explain purpose or why.

  1. Think about why you do it?Slide4
  2. Think how about how you do it?
  3. Think about when you do it?
  4. and then think about why again for each of the aforementioned questions?

The results of such questioning can provide

        • Allow for greater details to purpose
        • Provide a degree of control in a volatile, and constantly changing environment.
        • Generate an agency to be increasingly resourceful
        • Sustain your system

Step 2: Create a Specific Objective

The next step is to establish an objective and to delineate the why or purpose for said objective. A frame work can be meaningless without an objective.  In this case, the objective is simply to create interventions to diminish the risk of injury of the hamstring muscle group during practice, play or competition.  

This objective was created as a result of the  notorious impact in which hamstring injuries impact to sports

    1. hamstringit is a common occurrence in specific ranges of sports such as track and field, jumping, soccer, football, rugby as well as martial arts, dance and water skiing (Croisier, 2012).
    2. Hamstring strain injury is the most common cause of lost training and playing time in running-based sports (Opar, Williams, Shield, 2012).
    3. And In professional soccer, for example, approximately one in five players will suffer a hamstring injury in any given season and upwards of 20% of these will re-occur (Erickson, 2017).

Step 3: Establish Parameters

The next step is to organize this list frames by establishing or creating parameters. While life brings complexity in almost every facet , and one must consider a variety of perspectives when making decisions or operating a system. One can gain perspective more clearly through establishing rules and forming limitations for elements.

Here are just some of the frames gained from hamstring training both experience and research

  • Supporting Research Evidence (Crossier, 2012)
    • Intrinsic Factors Screen Shot 2020-04-16 at 7.38.01 PM
      • Modifiable/Non-Modifiable – Intrinsic –  Human – Tissue – Training – Agonist/Antagonist Muscle
      • Modifiable/Non-Modifiable – Intrinsic – Human – Tissue – Training –  Flexibility
      • Non-modfiable – Intrinsic – Human Intervention – Tissue – Age/Degeneration
      • Modifiable – Intrinsic – Human – Tissue – Neural – Pain (Low Back Pain)
      • Modifiable – Intrinsic – Human  – Tissue – Structure – Sacroilliac Joint Dysfunction
      • Non/Modifiable/Modifiable – Intrinsic – Human Intervention -Chronic Hormone Imbalance
    • Extrinsic Factors
      Screen Shot 2020-04-16 at 7.38.21 PM
  • Modifiable – Extrinsic – Human Intervention –  Performance Play – Fatigue to unsuitable structure and content of training – Human Intervention
  • Modifiable – Extrinsic – Human Intervention – Inadequate Warm Up
  • Modifications from Initial Strain
    • Modifiable/Nonmodifiable – Human – Intrinsic – Tissue –  Structure – Training – Mechanic Properties – Tightness
    • Modifiable/Non-modifiable – Human – Intrinsic – Neural – No Training – Function – Weakness
    • Modifiable – Extrinsic/Intrinsic -Human Intervention – Tissue – Surgery/Trauma –  Extensive Scar Screen Shot 2020-04-16 at 7.38.37 PMTissue
    • Intrinsic – Tissue – Muscular Calcification – surgery
    • Intrinsic – Changes in the Biomechanics and motor patters of sporting movements
    • Modifiable/Non-Modifiable – Intrinsic – Tissue – Training – Neural Inhibition
    • Modifiable/Non- Modifiable – Intrinsic – Psychological/Behavior – Psychological Stress
    • Modifiable/Non-Modifiable – Intrinsic – Psychological – Adverse Neural Tension
  • Questionable Options in Treatment
    • Modifiable – Intrinsic – Human – Culture – Training – Incomplete or Aggressive Rehabilitation
    • Modifiable – Intrinsic – Human – Culture – Rehab – Return to Play – Underestimate of an extensive injury
    • Modifiable – Intrinsic -Human –  Medicine – Prescription of Glucocortosoid
    • Modifiable – Intrinsic – Human – Drugs – Anesthesia – Use of Local Anesthetic 
  • Non Modifiable Risk FactorsScreen Shot 2020-04-16 at 7.39.09 PM
    • Intrinsic – Older Age
    • Extrinsic – Prior History of Hamstring Strain (more than twice as high of risk of a new hamstring injury) 
  • Intrinsic – nutrition
    • Modifiable Risk Factors
    • Strength
    • Fatigue
    • Imbalance
    • Quadriceps/Concentric Strength
    • Quadriceps Flexibility
    • Reduced Hip Flexor Flexibility
    • Strength and Coordination Deficits of the Pelvic ad Trunk Musculature


Why the need for parameters?

     When we look book on the research and our own experience, it is  immediately clear, that the notion of hamstring training covers many areas and has a number of factors and/or variable to consider.  So, in this sense we’ve discovered, many frames for our framework.  At this point we simply require some parameters and greater organization towards a specific objective in order to fix or build these frames together. This objective is instrumental in giving us direction and setting parameters by allowing us to understand that there are factors in which we can modify and those that we can’t when going through the training process. Age for instance is a factor which can’t be modified. We know that within these modifiable or non modifiable areas there are intrinsic and extrinsic factors we have to consider  when undergoing the training process. Intrinsic factors  are those which occur naturally or considered to be essential. Extinsic factors are those not considered to be naturally occurring and/or those factors not considered to be essential. Extrinsic factors for instance can represent performance play, and factors outside the control of the performance training environment.  The more we organize these frames, the more it becomes apparent that changes to an individual athlete’s injury susceptibility can be impacted by environmental factors as well as human.

    The more we set parameters In this process of organizing, the more we can become more aware of the things we cannot change that present risk, which in turn may provide better clarity on the things we can change.  For instance, it’s clear that we can change tissue structure. 

Step 4: Form a Test Question

How can we improve Hamstring Training (through influencing musculotendinous tissue) to mitigate hamstring injury in Team Sports during Off Season training  in the weight room setting?

This title elicits several of the parameters i wish to set.

    1. The inclusion of the weight room setting suggests acknowledges that athletes experience stressors for adaptation to sport in many different arena’s that includes, (the field, the bar, the kitchen cafeteria, and the weight room)
    2. And more specifically despite our understanding that extrinsic factors such as Practices or fatigue may play a role , we will not be focusing on this portion during this presentation. 
    3. The inclusion of team sports is an attempt to include both my experience in dealing with large teams in the weight room setting , understanding that our choices in these settings can be influenced by limited resources such as time, space, equipment, etc and i want to acknowledge this.
    4. It is also an understanding that team sports share a similar issue in dealing with hamstring injury
    5. I, reluctantly included, mitigation hamstring injury  but that is essentially the goal is limiting hamstring injury ( a goal that affects a number of us)
    6. And the time frame is the off-season with an implicit understanding that there generally is greater potential to make changes during this period as compared to the season.

Step 5: Feed your evidence within your framework to an objective decision making system.

While i’ve introduced you to the idea of establishing a framework and a process for training, i don’t know that i’ve accurately given insight to the distinction between these elements. I see the framework and frame building as a way of recording our experiences and evidence we learn into  a visual network of units where ideas, experience and evidence are organized and neatly arranged (as best can be). 

I recognize the OODA process as the underlying manner in which I facilitate adding new experiences, and evidence for the purpose of building  and editing to reach a greater truth or objective. A clear comprehension of these two functions gives way to a resource that i’ve flirted with for many years.  it’a  resource that many of us are beginning to have more common relationships in the age of information and data.

WestworldOn the show West-World, a sci-fi thriller dealing with the philosophical adventures on humanity, and technology and human technology.  Some recognize this resource as Dolores, and artificial intelligent robot,  hellbent on protecting the free will, but for the sake of this presentation, id like you to understand this element as a screen, much like the screen you are using to watch this presentation. As you are looking at this screen you are all interpreting this information  in unique ways, in sometimes faulty ways, but very much  in human ways. (Myself included

BrainMy journey in training, let alone what i’ve learned about life is that human beings are more than capable of making poor decisions. And it seems that more we learn about how human beings think, the more we realize that human decisions are riddled with faulty decision making. (Great Audiobook to listen to is Your Deceptive Mind: A Scientific Guide to Critical Thinking Skills).

The screen is a resource (among many) that we can use in accordance with a process  and framework building to not only help us examine whether our experience and evidence is  of quality and/or accurate,  but enable us to make better choices. Consider the screen as a counterpart able to lend decision making agency, based on the information we have provided.

Such a resource would be valuable as it would lend us a greater ability to remain

  1. Unbiased
  2. Consistent
  3. UnEmotional
  4. with an ability to recollect previous memory accurately and process that information with a greater degree of accuracy relative to the human being.

RehoboamIn the attempt to strategize better training, i see the value of  Dolores or her nemesis RE HOBOAM, an AI in Westworld, built initially to predict the future  and a choose  a better future. (or no free will) Whatever the case, the screen, i’ve come to describe is a spectrum of AI.  and while it may be fun to think of it as a complicated turing testing robot named Dolores whom one can bring into the weight room to help with training choices,,it’s best to understand AI in the way that is currently being used today.

Today we use AI to deal with complex problems, like injury and as a way to acknowledge the limitations of human perceptions, and  to test our assumptions  built on our frames and processes. That’s the way at least that I’m approaching training today and perhaps another factor you should consider in your own personal objective.

           Once, you’ve built a process, established frames, built on evidence and experience or your assumptions recorded it and have run it through a enough tests repeatedly through your  OODA loop,  it’s time to build your AI.

and by then you should realize that AI building I is unravelling in a myriad of novel ways today.  Fundamentally AI is build on complexity but it is not as complicated as you may think. -Which may be why we are beginning to see it’s presence in many problem solving scenarios including sport.

Three-layer-feed-forward-neural-network-designToday in sport the AI techniques or methods with the greatest potential were artificial neural networks, decision tree classifier, Markov process, and support vector machine.   A visual referecnce of Artificial neural networks might help you to understand, it’s relevance to training and the potential of use to your own complex problem solving.

Artificial neural networks is a network system formed by the complex and mutual connection of a number of basic units.  The network is based on highly complex, and uncertain outcomes.  – If that sounds familiar, it should. It is similar to the framework we established earlier for injury. Except, that can create outputs based off what we put in, and we have the potential to weight inputs and thereby affect the resulting output. It’s a calculator for a complex systems based on the framers you have selected.

Currently in the sports world, this process it’s being used  for concepts understanding  training load, training process/knee injury causes”,  heart defect detection, ground reaction force pattern, psychosocial stress factors, and screening. For injury risk prediction,  I  imagine such a resource can also be utilize for training to reduce injury risk. But in order to get meaningful outputs we have to carefully decide the premises we build our AI on and to this  we have to go right back to our framework built on our assumptions, evidence and experience. If we want Dolores to help us in the decision making process of injury prevention,  we have to come to some conclusive decisions regarding  factors in training to mitigate hamstring  injury in the weight room setting during and off season period


Step 6: Revaluate the evidence and experience fundamental to your frame and objective decision making system. 

I often take for granted, the varying standards of scientific evidence borne of publication from the number of Journals available to us today – the age of information and disinformation. It must be stated that we should remain rigorous in scientific process for investigating claims even after they have been published.  The next aim is to edit and rank the information we use as part of our framework and objective decision making system.  While it may seem intuitive that we are always choosing the best evidence to enter within our framework, the selection of evidence, is also subject to human fault and therefore should be evaluated by an objective decision making system.  Furthermore, this process should continue after we have entered our evidence to help facilitate the process of editing and adding new evidence for better decision making agency.


Croisier, J. (2012). Factors Associated with Recurrent Hamstring Injuries. Sports Medicine, 34(10), 681-695.

Erickson, L., & Sherry, M. (2017). Rehabilitation and return to sport after hamstring strain injury. Journal of Sport and Health Science, 6(3), 262-270.

Mendiguchia, Jurdan & Martinez-Ruiz, Enrique & Edouard, Pascal & Morin, Jean-Benoît & Martinez-Martinez, Francisco & Idoate, Fernando & Mendez-Villanueva, Alberto. (2017). A multifactorial, individualized, criteria-based progressive algorithm for hamstring injury treatment. Medicine and science in sports and exercise. 49. 

Opar D. A., Williams, M.D., Shield AJ. Hamstring strain injuries: factors that lead to injury and re-injury. Sports Med. 2012;42(3):209–26.


 The Art of The Squat Stance 

_DSC9120 (2)
“ Hence the skillful fighter puts himself into a position which makes defeat impossible and does not miss the moment for defeating the enemy”. – Sun Tzu

To understand the fundamental value of the squat stance is to appreciate a position that provides efficiency and effectiveness for multilateral function. 

We recognize The squat movement stance as essential for activities  basic human function such as sitting, lifting. However, in sport this fundamental yet complex stance provides the stage for executing a multitude of sportive tasks.  It is a position that also reverberates resilience to external forces. 

Functionally the squat stance represents a position of readiness

The squat stance can be recognized for its ability to place athletes  in a resourceful and efficient position for a multitude of functionally active movements.  In the squat stance one improves their ability to store potential energy for accelerative, jumping evasive, or attack like maneuvers. The squat stance employs  multitudinous function from a position of great stability when standing. In the Squat Stance one has the ability to maximize potential energy for synchronized use toward various evasive, jumping accelerative actions as well as the ability efficiently recover and/or absorb energy from these same maneuvers by returning toward the same squat stance.

         The squat stance demonstrates a complex composition of factors necessary toward understanding  human movement as it can reflect kinematic elemental systems such as neuromuscular control, strength, stability, and mobility from the ground up or standing position (Myer et al., 2014).  The various systems and components which support orthograde human posture owes its complexity, shape and function from human evolution and the evolving environment that has laid touch to human beings from their beginnings.  The human to environment relationship is an important foundation for exploring the art and special qualities of human movement.  And the squat stance a version of human upright posture,  unique among all mammalian creatures is a useful place to start. 

To appreciate the squat stance, one must evaluate human environmental demands – especially in sport. 

“Whatever one may think of it, the upright posture does not offer sufficient advantages for it to have persisted according to the classic criteria of natural selection …sufficient advantages” must have existed, and our ancestors were definitely able to fulfill the functional requirements of their environment and eventually acquired an erect locomotion. (Niemitz, 2010).


From an evolutionary perspective,  there appears to be a number of sufficient advantages for the transition from hominin quadrupedalism to bipedalism, that includes  the ability to resourcefully navigate varied environments, as well developing useful approaches to attack, defend and intimidate.  It is believed our early ancestors, valued bipedalism for the advantages it brought within their wooded habitat of the forest as well as the nearby shore where they walked and waded in shallow water finding rich food with little investment (Niemitz, 2010). The value of standing upright may rest on our ancestors desire to efficiently step through and around barriers in search for nutrients or resources.  Evolutionary scientists have also suggested that the adoption of bipedalism in hominins was associated with aggressive displays in which bipedal posture made the individual appear larger and more threatening.  Leading theory also suggests that early humans adopted an upright posture and gait to be able to wield resources for attacking and defending against their predators (Carrier, 2011).   

In the end, an evolutionary development associated with sufficient advantages in attacking, defending, intimidating and navigating multiple environments translated into  a closed-chain kinetic movement  that requires the activation of well over 200 muscles for proper function and serves as the biomechanical and neurological basis for several functional and multi-joint sporting movements.  The squat dynamically recruits most of the lower-body musculature, including the quadriceps femoris, hip extensors, hip adductors, hip abductors, and triceps surae as well as upper body  and supporting muscle groups such as the abdominals, erector spinae, trapezius, rhomboids, and many others) to facilitate postural stabilization of the trunk. (Schoenfeld, 2010)

Squat1To fully appreciate, the vastness in function and complexity of a simple squat is to recognize that balancing upright on two feet is fundamentally a human quality, one relegated to nature’s highest form of cognitive ability  The vertical arrangement of head, trunk, legs and feet with task specific links in the neck, spine, pelvis, knee and ankles to dynamically balance together is a testament to the power in design of nature or the divine.  The human being, a freely moving construct, in spite of the forces acting on it, exists on capricious ground, always an inch or two away from falling – and yet remains erect. In other words, The defying nature of human ability to stand resistant to fall, in spite of nature’s force, is a consequence of human cognition and construct.  

Dr.  Soo Borson Professor of Psychiatry and Behavioral Sciences, Director, Memory Disorders Program, University of Washington School of Medicine defined “Cognition” as broad range of largely invisible activities carried out by the human brain.  These activities include perceiving, thinking, knowing, reasoning, remembering, analyzing, planning, paying attention, generating and synthesizing ideas, creating, judging, being aware, and among others, having insight. (Borson, 2010). It is believed that these developed abilities give way to the potential for a habitually  erect stance maintained through the processing of gravitational and non-gravitational information.  Dr. John r. Skyoles desribes this processing as as a species specific vertical balance faculty that only came to be fully exploited through the evolution of early humans, larger brain size and the development of higher levels of cognition. 

The first step in appreciating and understanding the squat stance is to recognize that the multitude of skeletomuscular adjustments that allow for a constant perpendicular uprightness of the body axis to the ground in direct gravitational alignment, is born of (among other factors) a human brain capacity to balance. In particular, our evolved and developed human scope provides enough perspective to execute a complex balance system.  In a study published by the act of bioengineering and biomechanics, researchers defined human balance as  a system of organs and mechanisms, which generate postural reactions to counter the displacement from the equilibrium position of the body centre of gravity, and which control eye movement in order to maintain a stable image of the environment (Olchowik, G., et al.. (2015).  More than a system of generating reaction, the human balance system, is one that collects and communicates information for the execution of control and movement. It is a conglomeration of interdependent parts which serve to sense or collect valuable information through vehicles such as the vestibular, visual, proprioceptive systems, the musculo-skeletal system and the central nervous system. Interestingly, an important component in understanding balance is that to achieve it optimally, one must be able to collect and communicate impactful information ideally.

Perspective, a fundamental quality of art,  presents itself in the basis of human locomotor function and to the feasibility of the Squat. To glean information for function is important in movement and life, but perhaps as equally important is the perspectives in which we acquire such information. Leonard Da Vinci once said “Make yourself a master of perspective, then acquire perfect knowledge of the proportions of men and other animals.” This insight also serves as a central tenet to human movement and perhaps life.  Gain perspective, qualify these varied forms of information and acquire knowledge as well as an understanding of your environment. Researchers at the Medical University of Lublin, portray this idea in their description of sensory organization and its role in achieving human balance 

“Signals from the sensory organs are integrated in the central nervous system in order to maintain body balance. These signals are used to determine the position of the body’s segments relative to each other and to the environment. The displacement of the centre of gravity from the equilibrium position is also determined. The signals from the sensory organs are used to varying degrees, depending on the stimulation conditions. The greatest contribution is from those which provide the most reliable information about the actual displacement of the body centre of gravity from the equilibrium position.”   – (Olchowik et al., 2015)

Achieving the squat stance is the capacity to sense valuable information, from many perspectives, in a manner that is organized, hierarchal, systematically checked  for the purpose of making appropriate decisions to display a balanced state and to maintain a position which enables the potential for a multitude of higher functions.

       Biomechanists note that proper organization of sensory information, in maintaining body balance, leads to reliable sources of information about the position of the body centre of gravity for a given stimulation of the sensory organs. Insight into these various perspectives of sensory information and the faculty which organize them is a useful measure to gain appreciation for the complexity of the squat position and the systems that are intrinsic to the maintenance of balance and decision making.

There are three sensory systems which are understood to contribute to the maintenance of balance at all times.  We know them as the vestibular system, the visual system and the somatosensory system. These systems contain elements such as sensory receptors and communication vehicles or afferent neurons that are critical to providing information to the squat stance position.  However, each system and its parts are weighed and organized differently depending on both task and environment. 

_DSC9120 (1)When we maintain the squat stance with our eyes open and our feet placed  shoulder width apart,  it is the somatosensory and visual systems  that are chiefly involved in providing sufficient sensory information to maintain the balance necessary  for this quiet standing position.

        However, if we were suddenly required to squat on an unstable surface (such as a stand up paddle board in the middle of a  lake), the vestibular system suddenly becomes more involved in achieving a balance squat stance position.  (Li, Zhang & Dobson, 2018).  The flexibility in reliability of systems necessary for attaining information for balance  in an upright standing position is due in part to the inherent differences within each system as well as the vehicles which implore their function.




Borson S. (2010). Cognition, aging, and disabilities: conceptual issues. Physical medicine and rehabilitation clinics of North America, 21(2), 375–382.

Carrier, D. (2011). The Advantage of Standing Up to Fight and the Evolution of Habitual Bipedalism in Hominins. PloS one. 6.

Li, L., Zhang, S. & Dobson, J. (2018). The contribution of small and large sensory afferents to postural control in patients with Peripheral Neuropathy. Journal of Sport and Health Science. 8, 218 – 227

Myer, G. D., Kushner, A. M., Brent, J. L., Schoenfeld, B. J., Hugentobler, J., Lloyd, R. S., … McGill, S. M. (2014). The back squat: A proposed assessment of functional deficits and technical factors that limit performance. Strength and conditioning journal, 36(6), 4–27.

Niemitz, C. (2010). The evolution of the upright posture and gait—a review and a new synthesis. Die Naturwissenschaften. 97. 241-263.

Olchowik, G., et al.. (2015). The human balance system and gender. Acta of bioengineering and biomechanics / Wrocław University of Technology. 17. 69-74

Schoenfeld, B. (2010). Squatting Kinematics and Kinetics and Their Application to Exercise Performance. Journal of strength and conditioning research / National Strength & Conditioning Association. 24. 3497-3506.

Skoyles, John. (2006). Human balance, the evolution of bipedalism and dysequilibrium syndrome. Medical hypotheses. 66. 1060-10688.