Shoulder hyperlaxity is not the end-all-be-all of shoulder pain, but it is a prominent force that can be linked to pain, pain perception and motor planning. Like most other overhead sports, swimming requires increased shoulder mobility in order to complete each technique with good form. Swimmers will normally have excessive ROM from the repettive overhead strokes, and that’s OK within certain limits. Shoulder instability refers to the amount of translational motion the humerus has on the glenoid fossa. Translation can occur pain free and you will often find asymptomatic swimmers. Unfortunately, there are swimmers who can experience pathological laxity; referring to excessive glenohumeral (GH) translation that causes pain. Studies have shown that this laxity is noted to increase with a swimmer’s competitive level.
If overhead athletes are known for their repetitive motions and forces applied on the shoulder joint. So how is swimming different?
During practice a swimmer may swim anywhere from 4,000 - 10,000 yards or meters per practice. In 25 yd pool that converts to 160-400 lengths during the workout. If a swimmer takes 14 strokes per length (freestyle), we are talking about anywhere from 2,240-5,600 repetitions of overhead motion per practice! (Impressive when you look back and think about your swimming career, daunting when you think about what your coach has in store for this afternoon).
As the stabilizing shoulder musculature fatigues the joint capsule becomes the reliant structure. However, the capsule is suppose to be a last resort against external forces as it acts as a sling in the front of the GH joint. Now we see it being used to create stability in our swimmers everyday, throughout the progression of a swim stroke, from hand entry through the recovery phase. Much like a hair tie that’s been stretched too many times, once the GH capsule gets excessively stretched it loses its elasticity. Joint laxity can begin to create accessory motion that our swimmers can't control. A motor control gap can cause altered glenhohumeral and scapulothoracic biomechanics, abnormal movement patterns, uncoordinated muscle activation and eventually pain.
The research points to a correlation of shoulder pain and hyperlaxity, but that does not mean it is the causative factor. The knowledge of laxity shoulder be intertwined with a full examination.
Swimmers: If you ever feel you can’t control certain shoulder motions, or you just feel “unstable” talk to a coach or clinician (PT, AT etc.) and see how they can help. Remember to build your base BEFORE the season starts. As much as we want coaches to progress safely, little muscle imbalances can be corrected on your own. Take charge of your training!
Coaches: Think about implementing shoulder training to preseason conditioning. This shoulder focus on endurance stability and should progress cautiously as sometimes you don’t know what kind of shape your swimmer’s shoulder is in. Additionally stretching routines should be evaluated for utility and possibility of over stretching or capsular stretching. Ask one of our clinical professionals to come do a clinic, help with ideas and develop a plan for implementation.
Clinicians: Evaluation should always include joint mobility evaluation. Commonly used techniques are the sulcus sign, anterior/posterior drawer, and shoulder apprehension test. For swimmers it’s important to evaluate muscular imbalances in a variety of ROM. What may be provocative in one position may not be in another, the same thing goes for strength testing!
Grandeur Movement Science strives to be your expert in this category and provide the swimming community with the knowledge and tools necessary to prevent these types of injuries.Thanks for reading! Stay tuned for more.
Sam LaRiviere & Dan Fay
Grandeur Movement Science
References:
1. Tovin BJ. PREVENTION AND TREATMENT OF SWIMMER’S SHOULDER. North Am J Sport Phys Ther. 2006;1(4):166-174.