Anatomy of the Golf Swing Blog-post No. 4
Anatomy of the Golf Swing – The Shoulder Girdle (esp. Scapula)
[All descriptions are for a right-handed golfer].
The Shoulder Girdle, and, for that matter, all parts of the upper body, have one main function – to present the arms and thus the golf club to the ball in such a manner that the ball can travel as far, straight and high as possible. [For which results, the club must be moving as fast as possible and from an inside and shallow direction].
Often the terms ‘shoulder girdle’ and ‘shoulder’ are used interchangeably. They do, however, refer to completely different parts of the body. The shoulder girdle refers to two bones – the clavicle or collar-bone, and more importantly, for golf, the scapula or shoulder blade. [For more technical details on the ‘movement of the scapula and humerus’ see pg. 1861 in http://ptjournal.apta.org/content/66/12/1855.full.pdf].
The thin, triangule-shaped scapula has, on one of its corners, an indented area (the glenoid cavity/fossa), which serves as the ‘socket’, for the arm’s ‘ball-and-socket’ joint.
So the ‘ball’ (the top part or ‘head’ of the humerus or upper-arm bone) has a range of motion – in three directions – which is determined by which direction the scapula’s ‘socket’ is facing. In simple words, if the ‘socket’ faces up, the left arm can climb up across the chest more easily during the backswing. The opposite is true if the left ‘socket’ faces ‘down’.
Similarly, if the socket is presented forwards, with a hunched-forward shoulder, it restricts the range of motion of the right arm during the downswing.
[See how the right arm gets ‘crowded’ with a rounded back (pics on left, right arm in red) and is able to move freely with a flat right-side of the upper back (diagrams not to scale!)].
For the purpose of the golf swing, it must be noted that the main role of the ‘shoulder girdle’ or more specifically the scapula, is to be positioned so as to facilitate required directions of upper arm movement. The range of motion of each arm is determined by the direction in which its scapula is facing.
What are the expert opinions on the role of this region in the golf swing?
One result of a google search on the role of the ‘scapula’ or ‘shoulder girdle’ in golf, is Titleist Performance Institute’s C-Posture, or rounded shoulders. Two of several causes for this posture, they say, are – a lack of shoulder girdle mobility; or of scapular stability.
Actually, normal people have very stable scapular regions during the golf swing, simply because so many big muscles attach the scapula to the spine and the ribs.
Also, there is never any restriction of shoulder girdle mobility, AS LONG AS a golfer’s body positions the scapulae in the direction in which the arms need to move. UNLESS there is a CONFLICT of INTEREST in the roles of the scapulae and the arms, there is never a problem (with normal golfers).
The main lack of mobility in the area occurs when then right shoulder becomes protracted (hunched forward, with the right elbow staying behind, when seen from the side). Even young professional golfers with perfectly neutral spines (the lack of which TPI promotes as a big cause of poor swing mechanics) can get into a position similar to the dreaded C-Posture for various reasons (which will be discussed with the hip joint blog-post).
See the protracted right shoulder of many fine Tour Players:
See shoulders which are not protracted and allow a lot of freedom of arm movement in the impact area:
The protracted right shoulder is a problem because the humerus (bone of the upper arm) is not able to move freely off the scapula, and the right elbow and wrist are forced to straighten in directions they are not designed to straighten from, creating imperfect impact, as well as potential for injury at the elbow and wrist, when repeated over time. In other words, there must be gleno-humeral freedom of movement for an efficient, unrestricted downswing.
Looking at two consecutive positions during Suzann Pettersen’s downswing, with a protracted right shoulder pre-impact, can you see how her right elbow and wrist are bent at awkward angles? [Could that be why she had right elbow surgery in 2004? To see her entire swing motion see http://www.golfswinggallery.com/2011/suzann-pettersen-golf-swing/]
NOW THAT we understand that where the scapula faces is an important issue in the freedom (or lack of it) of the arms’ movement, we must ensure body positions which place the scapulae so that they do not interfere in the role of the arms. A mere correction of a C-Posture is not enough – even after a correction, or despite a perfectly neutral spine, a golfer can get the right shoulder (scapula) into position for poor impact.
The Minimalist Golf Swing not only positions the right scapula for better presentation of the right arm at impact (even for those with an existing C-Posture), but also positions the left scapula for a more efficient backswing (to be discussed in the blog-post on the shoulder/upper-arm).
The right scapula in the Minimalist Golf Swing, is rotated back, pre-swing, so that even a true C-posture-possessing shoulder region still has a long way to travel before it arrives at the ball, thus giving the right arm more room to move without being crowded-in by a protracted shoulder – see pic. below. [The above are not how-to comments, they’re strictly FYI].
Incidentally, have you ever FELT an over-the-top impact? A feeling of a crowded right shoulder and, if you look/feel closely enough, a right thigh which is pushed forward too much, too?
This FEELING is as old as the golf swing itself – one does not need swing video with circles, lines and angles drawn on a monitor to figure out a shot has been hit ‘over-the-top’ (ie. the club has arrived ‘over-the-top’ of the ball rather than approach it from its inside-right-quadrant).
