Updated: May 29, 2020
For some time I have been intrigued by what software developers refer to as regression testing. In short, when a new version of a software program is released, it is tested rigorously by independent end users to establish whether new bugs have been put in to the system as a direct correlation to the update. Developers never find their own bugs (which is also true for most of us when it comes to understanding more about how we function), therefore companies invest large sums of money on regression testing every time they launch a new version of their software to ensure it is robust and stable prior to being released for sale. This made me think about how we apply such principles to golf and essentially it led me to start to explore that when we make change in golfers effectively, what changes when we make change?
One of Sir Dave Brailsford’s many performance measures was to identify where the athlete could achieve marginal gains. As a small caveat to this we also have to acknowledge that in order to make gains, can we experience marginal or significant loses? With this in mind, if the losses outweigh the benefits then why are we making such changes, what’s the rationale behind our decision making, have we really identified the first breakdown in the motion and what it was being influenced by? During the past few months I have been looking closely at once a new signal, stimulus, piece of feedback is given to a player in the attempt to improve the function of a segment, joint etc... I have immediately captured and looked at the first 3-5 shots the player hits with this new awareness. Using the 3D data, this allows me to highlight what the player has changed in order to make the new change. Now as mentioned above, although there may be gains made in improving the understanding and function around the segment targeted, however has there been regression in other areas in order to make change? This provides us with much vital feedback, as effectively it allows us to understand several important influences such as:
How has the player interpreted change? How to they see, feel and understand the new movements?
At what cost has the change come with? Poor joint loading? Possible injury?
Have we achieved aesthetics over function? It may look better but is it working better? After all define what good is? Good can often be a matter of opinion which is effectively the difference between a book and research, a book is often one person’s view of the world where as research is invariably peer reviewed and subjected to rigorous review prior to acceptance.
How are they now moving around the new feels?
Has this identified areas within the golfers body structure that may find the new movement challenging (more on this later)
Have we provided the right environment, opportunity for them to make the new change?
Are their external influences that may be corrupting the player?
Let me share with you two recent case studies, the first one outlines that when improving one segment this allowed for significant improvement in another area, with the second study discussing that in order to change the behaviour of a segment this caused much regression elsewhere.
Case study one.
A player was commenting that they were not happy with how their pelvis was moving in the backswing and this had over time caused poor movement around their left hip which ultimately led to the player sustaining an injury. This movement was identified some time ago however as the way of the world, until things break often people do not listen, therefore it took the injury to happen for the player to accept that perhaps it is the way they move in swing that may be causing the left hip to react in the way it has, hence the problem. Many of you have heard me say that injuries often are a 3-5 year cycle of repeated loading the players go through before they experience pain and become symptomatic. On investigation of their swing patterns, it became quite evident that the left hip was being overloaded and being asked to make some pretty unhappy movements in swing. After discussion with the players’ coach and physiotherapist we all agreed that it was the way they moved in swing that was causing the problem. However, the first question that always needs to be asked when assessing movement is what is the joint, segment, muscle, club, ball etc... reacting to, what’s making what do what it does and what’s effecting what? How I make that call is to use the 3D data to establish what segment misfires first and what compensates elsewhere in order to move around the problem which is often what the player feels and we observe. In the case of this player, the first point of failure occurred with how they initiated backswing around their right wrist, this led to an imbalance and compensation then occurring around the right elbow and ultimately changing function and range of movement around the shoulder. Due to how the shoulder moved, this effected how the ribcage rotated by encouraging it to move into excess elevation which then caused a compensation to exist through the pelvis by encouraging it to put high levels of load around the left hip joint as the pelvis was attempting to rotate. As an example to show how valuable wrist function is on shoulder movement, if you invert the body and turn it upside down, the arm and leg perform similar roles – the wrist acts like the ankle, the elbow behaves like the knee and the shoulder works like the hip. In the world of biomechanics, it is commonly accepted that ankle and foot function is crucial as its this that supports the humans body weight, interacts with the ground as well as directly effecting lower limb movement (as well as other segments up the chain), therefore good ankle and foot function is vital in allowing for good hip control and movement. With this understanding, this is one reason why good wrist function is as valuable for golfers as a stable wrist allows for a more mobile shoulder. After discussion with player, coach and physio and taking them through the players patterns, it was agreed that the left hip was purely responding to what the right wrist was doing, therefore every time the player hit a shot they effectively put the fault back in. Using biofeedback, we addressed the issues around how the player moved around the right wrist at start of backswing and after a short while the pelvis started to move and behave in the way the player and coach wanted it to do as in short, there was no reason for it to react for something no longer misfiring elsewhere. Therefore we were able to understand more about what changes when you make change, in this case in order to change the pelvis we had to understand what the pelvis was being influenced by. This was a good example of achieving clear gains without regression and working at the first point of failure.
Graph 1 below shows reduction in right wrist extension at start of backswing.
Graph 2 shows improved loading around right hip joint at top of backswing as a result of reduced right wrist extension.
Case study two.
An example of regression around change occurred with the player discussed in this case example. This player was unhappy about their club delivery through impact, therefore the player and coach wanted to improve how the golfers trunk rotated in the backswing as it was causing some imbalances around how the trunk and arms matched up which ultimately led the player to recover in the way they did through downswing which is why the delivery behaviour of the club was less than ideal. The player wanted to achieve more rotation around their trunk in the backswing so feedback was given to assist with this. Capturing the first 3-5 shots with the player attempting to increase how much their trunk rotated in backswing, the 3D data reported back very significant regression in other areas, mainly around how much the spine was moving into left lateral flexion during the backswing and the increase in pelvis sway away from the target (reduced right hip internal rotation). The initial summary was although the player had increased rotation through the trunk, however at what cost and what has regressed in order to make this change? This prompted a couple of initial questions - How has the player interpreted change? Has a polluted signal been given? Are there conceptual, structural, environmental issues influencing how the player functions? Is there neural interference which requires the plasticity of these neural pathways to change? Have we simply passed the error elsewhere in an attempt to change aesthetics over function? Are we working at the first point of failure? Possibly the most important question that we may need to ask ourselves is do we need to explore and understand our own values more around how we see the way the golfer moves in order to best solve the problem. After all, there are multiple ways of achieving the same outcome which is reflected by the difference between eggs and branches – branches have to break to fall, however eggs have to fall to break.
After much further investigation it emerged that this player had an issue with their cervical spine as well as an articulation around another joint due to an accident they had as a child which was never really fully resolved when it happened. This caused adaptations through their frame as over time the body attempted to restore balance through adjusting other segments elsewhere. The brain knows in advance of completing any task what resource it has available, therefore is designs a road map using these resources prior to moving in order to achieve the task. By increasing how much their trunk rotates in the backswing, the player needed sufficient range around this part of the body and the supporting peripheral structures and tissues which it simply didn’t have available, therefore in order to complete the task they simply adjusted how they moved their pelvis and the angle their spine rotated around in order to rotate the trunk further. Therefore exactly what was achieved and was the regression worth the gain? In graph 3 below, you will see the increase in trunk rotation at top of backswing.
Graph 4 shows an in response to increased trunk rotation an increase in left lateral flexion, therefore placing the spine and supporting structures into a less than optimal position. Joints work best and are happiest when they move from and around neutral, they become unhappy and compromised when they are made to move in directions they do not enjoy or from poor starting positions, hence they will find a way to move around the problem, often causing irritation as well as compensation elsewhere.
Graph 5 shows an increase in pelvis sway away from the target as a reaction to increasing trunk rotation.
One use of the 3D data I capture is to look at the more inherent movements, such as segment interaction, acceleration/deceleration values, peak segment speeds, segment lags, sequencing etc... These are very intrinsic movements that have huge effects on areas such as driving distance, ball/club connection, adaptability and injury avoidance to name a few. When making change, often some of the greatest gains to be had are by improving and enhancing these values, however it is also where some of the greatest regression can take place hence aesthetics over function.
This article provides a very small and short introduction around regression testing in golfers and it is something I am going to investigate much more over time. Working with the understanding that everything effects everything, when looking at large or small 3D datasets (or whether using launch monitors or other measurements devices where data is extractable) start to look at what’s changing when you make change. Analysing large sample of data can provide valuable feedback around correlations, abnormities and patterns, however I like using small datasets to start with as this is where the minutiae of change can be found as like mentioned, often what happened within the first few shots post intervention can reveal huge amounts of information as to how players interpret change and how the body attempts to move different in order to problem solve. This is a very in depth subject which requires considerable more discussion, investigation and exploration, however as a starter for the discussion the next time we make change in our athletes in an attempt to achieve gains, ask ourselves what may be regressing in order to make gains and have we really identified the first point of failure and what it is being influenced by, as if you can address this then invariably you will see significant gains with minimal if any regression. Possibly the most important question to start with is what’s effecting what?