Updated: May 29, 2020
Despite the varying preferences of many coaching concepts, one body segment that typically attracts consistent debate is the function of the right arm within the golf swing. For the purpose of this discussion, all references are for a right handed golfer.
For me, one element of good golf swing biomechanics is the connection between right arm and trunk throughout back, down and through swing. Good function here often encourages good quality rotation and postural control, which subsequently helps create good swing dynamics such as ideal kinematic sequencing, body speeds/timing lags as well as helping to reduce undue stress and load throughout the entire chain, leading to minimising the chance of injury in high risk areas such as low right side of back, wrists, elbows and neck.
Good function of the right arm involves two main ingredients, firstly a structurally stable and mobile scapula/GHJ and secondly, a clear concept of how the wrist joint moves, primarily in takeaway. For point of clarity, connection in my definition is how stable the scapula sits on the ribcage, not how close the elbow remains to the trunk as it can often be misinterpreted as.
So in the world of biomechanics, what constitutes right arm function? At set up, the right scapula ideally will sit 'flat' against the ribcage, with the right forearm slightly supinated. This can often create the feel for connection in around tricep, arm pit....In takeaway, the right wrist works radially, the forearm supinates/rotates, the elbow moves into flexion with the humeral head sitting down. As a reference point, the elbow remains in front of the seam on your shirt, with the wrist in front the elbow. From waist height to the top of backswing the right wrist continues to work radially, the forearm moves into pronation, elbow further flexes and the humeral head remains sitting down. Biomechanically, this is good function, connected and best placed to encourage optimal trunk arm connection in down and thru swing, leading to ideal club delivery.
However a common pattern of dysfunction that I regularly witness is one where at set up, the right arm hangs excessively forward of the trunk, leading to the right scapula to elevate and protract. Essentially it can provide the golfer with the feedback of feeling 'switched off'. Therefore a pattern of poor biomechanics (pathomechanics) occurs in takeaway, as the right wrist moves into extension, as a compensation the elbow moves into excessive flexion with the forearm over pronating, additionally the humeral head elevates causing over activity around upper trapezius, levator scapulae and pec minor, in comparison a right arm with good function will recruit the muscles that best stabilise the scapula, namely serratus anterior, lower trapezius, triceps....
As a result of these swing breakdowns, numerous compensations can exist in the backswing such as excessive left lateral flexion in the spine, poor control of the pelvis and lower limb. Consequently, numerous recovery moves arise in the downswing as the golfer attempts 'to find impact'. It is these recovery moves that invariably cause both poor shot patterns and injury. When assessing the cause and effect patterns that lead to right arm dysfunction, consideration should be given to both local and global influences, such as postural adaptations, poor body structure, swing breakdowns happening elsewhere leading to right arm compensation, poorly fitted equipment (often seen in junior golfers) plus swing concepts that are often the root cause of many issues.
Below is an example of good right arm connection at address.
Below is an example of good right arm function in takeaway.
Here is an example of good right arm function at the top of backswing.
From a biomechanical/3D perspective, although there is no such thing as perfect, normative values of how the right arm work in function/dysfunction are shown below.
Note in good function ( green line) how the right wrist works into radial deviation (RD) with values of 22°of RD, whereas in dysfunction (blue line) it only has just over 4°of RD, limiting the ability to optimally load the joint, instead causing compression through the areas such as scaphoid, lunate, triquetral and the surrounding tissues etc. as shown below:
Additionally, the graph and values below chart good right arm function, with regards to wrist extension/flexion, radial/ulna deviation, forearm pronation/supination and elbow extension.
To summarise, check with your physio that you have sufficient control and range in and around your shoulder/scapula, as well as rehearsing good wrist/arm movement in a mirror, as this will help you connect your body feels with your swing feels and assist in improving all round body function and golf swing biomechanics.