Physio: Swimmer's shoulder develops from overuse
During this Okanagan heat wave, many people are hitting the water for leisure or to train for upcoming races.
Like any sport, aches and pains can occur in swimming, with shoulder pain being the most common complaint. The term swimmer’s shoulder is used to describe painful shoulder overuse conditions that occur in the sport.
The shoulder is a ball-and-socket type of joint, which allows for a large amount of motion. This excessive mobility is balanced by surrounding tissues to make it more stable. Included in the structures that help stabilize the shoulder is a fibrous capsule that surrounds the head of the humerus (the arm bone), as well as the rotator cuff.
Four muscles make up the rotator cuff and serve to keep the humerus properly placed in the joint. The bony structure that you can feel on the top of your shoulder is called the acromion, under which muscles and bursae pass and where impingement can occur.
Many movements occur at the shoulder during swimming, a lot of which is overhead. Different swimming strokes involve different patterns of motion, but all have some combination of rotation, circumduction and scapular movements. As the arm reaches overhead, especially if it is also in internal rotation, the shoulder is placed in an impingement position. To give an idea of the position of the arm, think of the stroke pattern used in the butterfly.
Injuries to the shoulder complex from swimming are typically microtrauma: small injuries over time from the repetitive activity rather than a macrotrauma from a one-time incident. There are many factors that can contribute to injury, both from within (such as the anatomy of the joint) and external (how the joint is used).
Intrinsic factors: • If the capsule surrounding the joint is tight at the back, it pushes the humerus forward, increasing the likelihood of impingement of the tissues under the acromion and placing more stress on the tendons of surrounding muscles • A lax (hypermobile) shoulder joint places more demand on the rotator cuff muscles • Muscles that help maintain space under the acromion during movement, or to control the joint, can fatigue, which then can affect stroke pattern
• Rounded shoulders with increased forward bending in the upper back is a common posture in swimmers. This lengthens and weakens muscles that stabilize the scapulae, can contribute to a tight posterior capsule and decrease mobility in the spine.
Extrinsic factors: • Overuse: training so often than the tissues don’t get a chance to recover • Misuse: swimming with improper form; for example, not enough rotation of the body during a freestyle stroke pattern • Abuse: placing too high of a demand on the muscles and joint (for example, using hand paddles)
• Disuse: atrophy and weakness can occur when time has been taken off from training.
So what can be done to prevent or treat this kind of injury?
It is important to get a correct diagnosis and to assess where the problem lies. Any impairments should be addressed, which can include mobilizing stiff or tight structures, strengthening the rotator cuff and other supporting musculature and improving technique.
Be cautious of overtraining—don’t increase your distance, intensity or frequency of training too quickly. Give yourself adequate time to make strength and endurance gains, as well as time to recover.
Consulting your physiotherapists to address shoulder and posture impairments and a coach to look at your form, can help keep you swimming strong this summer.