So what is the Serratus Anterior? It is a muscle that is attached on one end to the underside of the inner scapula (shoulder blade) and fans out in serrations (hence name) to attach to the lateral and lateral anterior portions of the first 9 ribs.
Injury results in pain to the muscle site mostly, but can also refer through the shoulder, down the arm and into the neck.
What is its action? The Serratus Anterior works a few actions:
- Protracting the scapula (moving it anteriorly around the rib cage).
- Acts to anchor the scapula to the thorax when using the arms.
- Aids in turning the shoulder socket upwards to allow arm movements above shoulder level.
The first two actions apply very strongly to golf. In fact in the duration of the golf swing the leading and trailing arm Serratus Anterior muscles will rarely fall below 20% of its maximal muscle tension. This makes it one of the most active (percentage of maximum wise) muscle’s in the whole swing.
This is particularly the case in the leading left arm which is predominantly where the Serratus Anterior is injured. This prolonged activity in the swing, when repeated over many hits, can lead to fatigue in a weak muscle which will either cause injury to the muscle or compensatory swing movements.
- He started hitting 100 extra balls a day (leading to increased muscle fatigue?)
- Changed his downswing to come back slightly over-plane. Though technically this was probably warranted (I’m not a swing coach), this create’s more work for the Serrratus Anterior to control the scapula as the arms are slightly further from the body.
Firstly, normal acute muscle injury management (physiotherapy and relative rest as advised). Then, when appropriate, exercise’s to start increasing Serratus Anterior strength (push-up plus etc.).
Lastly, a specific screening through the upper limb and back.
With training the golfer will have to moderate the number of balls they hit when returning until the Serratus Anterior gets stronger. If pain remains after all these steps, the coach may have to intervene technically.
If ignored and played ‘through’ the pain and muscle function will only deteriorate. In some golf case’s continued training and hitting of excessive balls (with a fatigued and/or strained Serratus Anterior) can lead to development of stress oedema and eventually stress fracture’s developing at the rib attachments.
This outcome leads to a long duration of complete rest and more complicated management.
So as with any injury, get onto it and fix it straight away.
Martin McInnes - Physiotherapist