Today’s podcast features Bill Hartman.  Bill is a physical therapist, and in-demand educator in his approach to restoring a pain-free lifestyle, and understanding the governing principles of movement.  He has been a mentor to, or has inspired the knowledge of many previous guests on this podcast, particularly in regards to movement biomechanics, infra-sternal archetypes, and the compression-expansion model.  Bill owns IFAST Physical Therapy in Indianapolis, Indiana and Co-owns Indianapolis Fitness and Sports Training with Mike Robertson, where he works with clients ranging from very young athletes to professionals. It is very interesting to look at how we approach the nature of “muscle weakness” and compensations in training.  For example, it is common to look at all compensatory action in the body as a “bad thing”, rather than looking at how the body actually uses compensatory action to produce force, or adapt to a particular sport skill, in addition to when that compensation might actually be a problem.  The human performance field has also looked at muscle weakness in isolation, rather than digging deeper into the underlying structural alignment of the body contributes heavily to what we are seeing out of muscle strength and function. In today’s podcast, Bill goes into the adaptive nature of the body and what it really means when we are seeing compensatory actions in movement.  Within this, Bill also gets into the nature of reciprocal, or more “locking” movement of joints, depending on the task an individual needs to accomplish.  Bill spends a lot of time talking about strength training, how it can be a positive, but also the dynamics of the interference effect that can lead to undesirable adaptations for athletes over time.  Bill also covers external rotation and pigeon-toed athletes, and the nature of power training for wide and narrow ISA archetypes, and much more. Today’s episode is brought to you by Lost Empire Herbs, Exogen wearable resistance gear, and the Just Fly Sports Online Courses. For 15% off your Lost Empire Herbs order, head to lostempireherbs.com/justfly. To try Pine Pollen for free (just pay for shipping), head to: justflypinepollen.com. To learn more about the Sprint Acceleration Essentials or Elastic Essentials courses, head to justflysports.thinkific.com View more podcast episodes at the podcast homepage. Timestamps and Main Points 5:00 – Bill’s journey from working purely in the traditional therapy and training model, into one that embraces more of the complexity of nature, and universal principles of movement 15:28 – The adaptive process of the body, and how this leads into different alignments and representations 18:14 – The compensatory strategies of the body as an adaptive process 29:02 – Examples of when strength gains may end up creating an interference effect on the body 33:32 – How children are so flexible, and the role of shape change in human motion 36:50 – The role of mobility and “stiffness” in terms of speed and running efficiency 43:37 – General thoughts on stiffness and compliance for a typical field sport athlete 49:10 – Connective tissue and stiffness adaptations to heavy strength training, and the point where heavy strength can be a negative for explosive sport activities 1:04:45 – Relative motion and force production biomechanics in squatting, and knee mechanics as it relates to joint pain and injury risk 1:12:42 – The externally rotated, “bowlegged” representation of the legs, on the level of athleticism 1:23:16 – Power training with the needs of a Wide ISA type in mind Bill Hartman Quotes “When you start to look at the human as a complex adaptive organism, your perspective starts to change” “If you are made of water (fluid dynamics) is going to be one of the foundational principles” “The goal is not to negate everything that came before… but the level of reasoning is what the biggest change has been...