Updated: May 29
Reflecting on my own coaching experiences as a young player, one of the more common instructions I was given was ‘turn your shoulders’. Back then when I was 13 I never really understood what they meant, therefore like most young players I simply did as I was told and copied what I was being shown. So much for discovery, understanding and autonomy!
Golf is full of phrases such as shoulder rotation, and one could argue what harm does it do as long as the player moves in a healthy way, however young aspirational players are now much more educated in golf than I was at their age, plus much of the issues observed in later life (late teens onwards) come from definitions that are not accurate which then invariably end up creating a problem rather than solving a problem due to how players then interpret and achieve the movement based on the words used. The use of clean, accurate, non-contaminated language is vital as this asks and allows the player to interpret the command and produce a movement strategy without bias.
Therefore, let’s look at shoulder rotation and what this really is in golf compared to what some may think it is.
Shoulder rotation as it is historically known by some is actually ribcage/spinal rotation in golf. However, with the latest information now available we can now see and understand the activity and ranges achieved around the shoulder joints (glenohumeral joint – GHJ), what orientation the shoulder moves in and how this matches up with what I was led to believe as a young boy the movement called shoulder rotation. When looking at the historical definition of shoulder rotation in golf, to achieve and produce this movement it is actually the ribcage moving around the spine. For the spine to allow this movement to happen, multiple anatomical influences need to function correctly and this is an area we will discuss in future articles, however keeping this article primarily around the movement in the golf swing, locally the spine recruits the rotation available through the cervical and thoracic spine. For most subjects, there is at best 10°of rotation available through the lumbar spine as each vertebrae has ~ 1-2°available, therefore although it is a small contributor to ribcage/spine rotation, the main provider of rotation is through the thoracic and cervical segments. So let’s explore one of the first questions that perpetuates in golf which is ‘in the backswing, turn your shoulders 90°’. When it comes to 3D movement, one could say turn in what direction as there are multiple directions the shoulder joint can move in. Using two top 10 players in the world as case study samples, you will see that they achieve very different levels of ‘shoulder rotation’ at the top of backswing, one produces maximum rotation of 63° whereas the other achieve maximum rotation of 111°. Therefore where has 90° come from and how/where is 90° being defined?
Therefore based on what we now know, lets look at the patterns the shoulder joints move through in golf, the ranges they produce and how it matches up to and relates to the ribcage movement.
Let’s start with defining shoulder rotation in golf. My definition is humeral orientation relative to thorax orientation, in short the upper the arm relative to the ribcage. Anatomically, you can have significant amounts of ribcage rotation in golf, however minimal shoulder rotation. let me give you an example, if you take your start position in golf and fold your arms across your ribcage, rotate your ribcage through backswing, how much did your shoulder joints rotate and change orientation relative to the ribcage from start to top of backswing? The answer should be close to zero, therefore how much have the shoulders rotated in the backswing? So, let’s look at what really happens across both shoulder joints in swing and explore the movements and ranges both joint move through.
(These patterns and descriptions are for healthy, functioning joint however there are multiple different patterns and values achieved, however it is unusual to see a player achieve a different orientation of the shoulder throughout swing.)
Lead shoulder up/down – elevation of the humerus relative to the forward/backward bend of the ribcage.
Lead shoulder abduction/adduction – the horizontal movement of the humerus across and away from the ribcage relative to ribcage rotation.
Lead shoulder external/internal rotation - the external and internal rotation of the humerus relative to the rotation of the ribcage.
Throughout the backswing, relative to the movement of the ribcage the lead shoulder primarily moves through three patterns, internal rotation, adduction and elevation (this is not the shoulder moving up, it’s the humerus/upper arm bone moving up relative to its start position against the ribcage). Therefore at top of backswing the humerus is internally rotated, adducted and elevated relative to the orientation of the ribcage. Observed ranges the shoulder moves through during the backswing and the values observed across healthy, functioning joint are:
Internal rotation from address to top ~ 35°
Adduction from address to top ~ 40°
Humeral elevation from address to top ~ 35°
Typical in very powerful players the lead shoulder further adducts as the ribcage rotates clockwise at the start of downswing, with the shoulder also externally rotating and moving down where on impact, it is not unusual to observe the lead shoulder values on impact to be:
External rotation from top to impact ~ 30°
Abduction from top to impact ~ 25°
Humeral depression from top to impact ~ 30°
Post impact to finish, this is where the shoulder starts to display the highest rotational value with it moving into significant levels of external rotation, abduction and elevation, ranges achieved can be:
External rotation from impact to finish ~ 60°
Abduction from impact to finish ~ 45°
Humeral elevation from impact to finish ~ 30°
Therefore the shoulder moves through a very defined 4 dimensional pattern (3 orientations over time).
Trail shoulder up/down – elevation of the humerus relative to the forward/backward bend of the ribcage.
Trail shoulder abduction/adduction – the horizontal movement of the humerus across and away from the ribcage relative to ribcage rotation.
Trail shoulder external/internal rotation- the external and internal rotation of the humerus relative to the rotation of the ribcage.
Throughout the backswing the trail shoulder move into external rotation, elevation and abduction. You will note that the ranges the trail shoulder moves through in the backswing are very different than the lead shoulder.
External rotation from address to top ~ 50°
Abduction from address to top ~ 40°
Humeral elevation from address to top ~ 15°
Throughout the downswing, the trail shoulder moves through internal rotation, adduction and depression with observed values typically:
Internal rotation from top to impact ~ 35°
Adduction from top to impact ~ 30°
Humeral elevation top to impact ~ 10°
Post impact through to finish, the trail shoulder moves further into internal rotation, elevation and adduction.
Internal rotation from impact to finish ~ 50°
Adduction from impact to finish ~ 50°
Humeral elevation from impact to finish ~45°
Based on what we now know, what can we learn and how can we use this information?
Throughout the golf swing, the shoulder joints moves through very different patterns, with significantly different ranges. When we include the ribcage, it now starts to become more involved as we have multiple joints and segment moving in many different directions and ranges.
As discussed in previous articles, when looking at anatomical movement, everything effects everything therefore we cannot look at joints in isolation as invariably if there is an imbalance or adaptation around a joint, it can be in response to dysfunction elsewhere. However, for the purpose of this article and discussion, let’s look locally at the connections formed and the reliance shoulder function has on other segments/joints/articulations. Vital to good shoulder (GHJ) movement are scapula positioning and control, humeral head positioning, neck and upper spine posture and ribcage positioning. Dysfunctional posture or patterns around these joints will almost certainly create a bad response around the shoulder leading to reduced options available to the joints essentially leading to a compromised and dysfunctional pattern.
How we test structurally for good shoulder function in golf. Correctly, defining healthy shoulder movement anatomically will look for the clinician to look for expected/accepted ranges, however in golf do we really need what we have been led to believe for a period of time by some to have 90°of external rotation around both shoulders when the shoulder does not achieve these values in swing. Also, what these tests typically measure is how the joint moves in isolation, what is often does not acknowledge is the ribcage rotates with the arm in golf therefore perhaps a more accurate assessment of shoulder joint function in golf is to allow the ribcage to move with the arm in the way it can in the golf swing to provide a more valuable and relevant measurement for golf. Occasionally, what is measured/required and seen as the accepted normative value in anatomical assessments may not be required for the task the human is attempting to complete, however this will always be best answered by the clients question and the objectives from the session.
Prioritising the importance of good postural awareness, control and function around the neck, upper spine, GHJ and scapula, an area observed in many humans currently as showing as areas for concern.
Setting clear coaching concepts as to what patterns the shoulders move through and what patterns are best avoided. This is crucial as it helps avoid confusion in players as well how they are trying to achieve the movement historically referred to by some as ‘shoulder rotation’ as invariably they adapt and adjust other segments in an attempt to achieve what they understand to be shoulder rotation. This was me as a 13 year old!
The use of clean, accurate language as many issues are created by how the individual interprets the words used. This is where stats can be commonly misused, for example when used in campaigns, people will quote how a nationwide survey has over 100,000 signatures for a particular petition, well in the case of The UK that’s close to 59 million people not signing the petition so how you wish to read figures is very much the fun of interpretation.
Connection to shoulder related injuries. Understanding the patterns the shoulder moves through will help us best predict, avoid and in some cases rehab injury. Also, many elbow and wrist related pain can occur in response to dysfunctional shoulder movement
How shoulder rotation influences club delivery and launch monitor data. One study I am looking at (mainly anecdotally currently) is club delivery data vs. shoulder rotational patterns. Once I have a larger sample with some clearly defined patterns, I will share for discussion. One of my many aspirations is to continue to explore new information and question conventional thinking, after all perpetuation can be the death of all progression. Therefore with better information and more accurate solutions we can hope to aspire to create two main objective – more expansive, educated and evolving coaches/trainers etc. and healthy, better movers and hopefully more skilled players, if we can achieve this then we will be in a good place as in the case for human development, perhaps the biggest fear in life as things will remain the same...