Trunk Training for the Youth Athlete: Part 1
Defining the Trunk
The powers of social media mean every man and their dog has an opinion on how best to train the muscles of the core, or what will be defined in the rest of this post, as the trunk.
Rather than talk about aesthetics (because let’s face it…young kids have enough of that to deal with), this blog post will focus on the role of trunk training in terms of athletic performance.
Before we dive into the nuts and bolts, let’s start with a definition of what the trunk and the function of the trunk actually is.
Everything between your knees and your neck is the trunk, and the role of trunk is to help create motion, resisted unwanted motion and ultimately transfer force between the lower and upper extremities.
The trunk should be able to perform all of these actions in all 3 planes of movement (more on this later) and respond to both low and high load stability challenges with the appropriate amount of effort (Barr & Lewindon 2014).
The reason why definitions in training are important is because how we define a certain training concept will ultimately dictate the exercises we select and the methods we utilise to train the trunk.
Based on this definition, our trunk training should:
· Involve up and down movements, side to side movements, rotational movements (i.e. movement in all 3 planes)
· Should help us create and resist forward and backward bending, sideways bending, and rotation
· Involve transferring force from the lower extremities to the upper extremities (Fletcher, 2014)
· Prepare us to deal with both low load and high load stability challenges in an appropriate manner
Based on this definition you should also see how a trunk training program that consists of endless crunches and planks will not cut the mustard with athletes.
Crunches are simply up and down movements, so this fails to tick the box of working in all 3 planes, with some researchers reporting that crunches may unwanted and unnecessary stress to the lumbar the interverbal discs (McGill 2007).
Planks involve no movement…so whilst this ticks the box of resisting movement…it doesn’t tick the box of helping us create movement.
Why there is no 'Best' Exercise for the Trunk
This is not to say every movement in our trunk training program should tick every box, however, if we are not ticking all these boxes, then we are leaving untapped performance potential on the table.
If we take a whistle stop tour of the anatomy of the trunk, we will soon see why there is no such thing as the 'best' exercise to train the trunk, and this is in part because we have certain muscles of our trunk are designed for specific roles within our body.
The trunk can be subdivided into smaller sections, which if well trained, can provide the appropriate level of stability at the appropriate time.
These smaller sections include:
· The local stabilisers-these muscles are closest to the spine, smaller, and as such are best suited to responding to low load stability challenges, such as changes in posture
· The global stabilisers-these larger muscles of the trunk are better suited to helping resist unwanted motion and as such they act as the body's brakes
· The global movers- since these muscles attach furthest away from the spine and are larger these are muscles are best suited to creating motion.
In terms of responding with the appropriate strategy, you can soon see how relying solely on the smaller muscles of the local stabilisers might not be ideal if our foot is hitting the ground with 10 x our bodyweight going through us when we sprint.
On the flip side, if we're recruiting the larger muscles of the trunk simply bending over to tie our shoe laces, we are expending unnecessary energy, and tiring ourselves at an incredibly inefficient rate.
Categorising Your Trunk Training
Now that we’ve established how certain sections of the trunk are suited for specific purposes let’s talk about categorising our trunk training.
Trunk stability exercises can be classified as those with little to no motion occurring in the spine or pelvis. Typically, these exercises are performed for longer durations to ensure the slow twitch fibres have a chance to be recruited, as such they could interchangeably be termed local muscular endurance or trunk capacity exercises. Trunk stability exercises, include, but are not limited to:
· Plank variations
· Any static holds (typically short levers, e.g. isometric glute bridge)
Trunk strength (which will also be referred to as high load stability) are exercises where the athlete attempts to resist excessive of unwanted motion of the spine and pelvis through a larger range of motion (e.g. excessive rotation, side bending, spinal bending). Typically, these exercises should involve longer levers and/or the additional of external load. Trunk strength exercises include, but are not limited to:
· Anti-rotation presses (also referred to as Pallof Presses)
· Loaded carries (e.g. Farmers walks, suitcase carries, overhead carries)
· Longer lever trunk exercises (E.g. hanging leg raises)
· Barbell roll outs
Trunk power-exercises that look to increase rate of force production of the core musculature. These exercises should be performed explosively, include some form of force transfer and ultimately include a ‘release’ phase (think med ball throw variations)
In the following parts of this trunk training series we will explore these concepts in greater detail:
· How to assess where your athletes are at in terms of their trunk training
· How these types of trunk training relate to sport
· Some practical tips for embedding trunk training into your program
· Examples of a trunk training program
Written by Todd Davidson
About the author
Todd Davidson is a UKSCA accredited Strength and Conditioning Coach currently working at Downe House school, in charge of the scholarship athletes' strength and conditioning program whilst introducing athletic development into the P.E curriculum.Todd's current interest on youth athletes was sparked by gaining experience with University, Paralympic and Olympic athletes as part of his internship roles with Duham University, Middlesex County Cricket Club and the English Institute for Sport, with GB Boxing and Paralympic Table Tennis, and speaking to other practitioners as to how this journey can be scaled more effectively to reduce injury risk, enhance performance and improve athletic development in youth athletes.
Todd can be found via:
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