By Bart Brys
Swimming is regarded by many the ideal form of exercise because it is injury free.
Physical problems such as swimmer’s shoulder and breaststroke knee, normally only
occur with intense pool training, combined with heavy weight training. Bad technique
can also assist in creating microtrauma.
Besides explaining the swimmer’s shoulder, I’ll be looking at causes and prevention.
In order to fully comprehend the causes of swimmer’s shoulder a basic understanding
of the anatomy of the shoulder is required. So let’s get started.
WHAT IS SWIMMERS SHOULDER?
Swimmer's shoulder is more properly known as painful arc/ rotator cuff tendinitis, or
Impingement syndrome refers to the mechanical compression and/or wear of the
rotator cuff tendons as they pass under the bony structure of the shoulder.
Literally, impingement means contact or collision between the upper arm bone and the
softer parts of the shoulder. When does impingement occur?
Try the following: stretch your right hand out in front of you. When your thumb
points up, that is the neutral position. Now, twist your arm so that your thumb points
to the left, that causes moderate internal rotation of your shoulder. When you twist
even farther, so your thumb points down and your pinky points up, that causes
extreme rotation of the shoulder. In plain English, the upper arm bone is rubbing
against the soft muscles and tissues harder than it would if your hand and arm weren't
turned out. This rubbing and compression can cause inflammation resulting in a
persistent increase in pain, tenderness, and loss of motion in the affected shoulder.
ANATOMY OF THE SHOULDER
The shoulder girdle is made up of 3 bones: the
scapula (= shoulder blade), clavicle (= collar
bone) and head of the humerus (= top of upper
arm bone), 2 joints, and numerous ligaments,
muscles, and tendons. A gel like bag lies
underneath the acromion (part of the scapula). It
overlies the rotator cuff and can provide it with
some mechanical protection from the bony
acromion above in the face of impingement.
The shoulder is a ball (humerus) and socket (scapula) joint.
A group of 4 muscles helps to move your shoulder joint - they are called the "rotator
cuff". These muscles work together to help get your arm up over your head, as well as
rotate it in and out. That is why rotator cuff injuries generally result in weakness,
especially in trying to raise the arm overhead.
In addition, these rotator cuff muscles function to help keep your shoulder "in socket",
or "located" (when the shoulder comes out of socket, it's called "dis-located").
A healthy rotator cuff is essential to shoulder strength, flexibility, and control. One
potential outcome of impingement syndrome is a rotator cuff tear.
To better understand how the shoulder works in swimming, it may be helpful to think
of the upper extremity as a lever or “canoe paddle” mechanism. The swimmer's hand
functions as the flat end of the paddle. The rotator cuff functions as a fulcrum
stabilizing the joint between shoulder blade and upper arm so that the power muscles
of the shoulder are able to pull the arm through the water. This would be analogous to
the way in which a canoeist uses one hand to stabilize the upper end of a paddle as a
fulcrum, so that the lower hand can pull the paddle through the water more efficiently.
Many swimmers do swim with extreme or moderate internal rotation without apparent
pain or injury, but for many other swimmers, constant extreme internal rotation during
swimming will eventually cause impingement, irritation, chronic pain and injury.
Some research indicates that even moderate internal rotation while swimming tends to
increase shoulder impingement.
Swimmers may have shoulder pain for many reasons, including:
1. Poor technique
3. Unilateral breathing
4. Training equipment
Poor swimming technique is a major factor in shoulder pain. Both the pull-through
and recovery phase of freestyle can lead to impingement.
The pull-through phase of freestyle begins when the hand enters the water and
terminates when the arm has completed pulling through the water and begins to exit
the surface. If a swimmer crosses mid-line upon hand-entry, or if the hand enters the
water with the thumb pointing down and the palm facing outwards, this can result in
The reason is that with an hand-entry (= beginning of pull-through) across the mid-
line of the body, the shoulder is placed in a position that creates impingement. A
crossover pull-through usually results from a crossover entry and increases the time in
the impingement position. Proper body roll, however, can resolve most of the
The recovery phase is the time of the stroke cycle when the arm is exiting the water
and lasts until that hand enters the water again. As a swimmer fatigues it will become
more difficult for him to lift his arm out of the water, and the muscles of the rotator
cuff become less efficient and changes of impingement increase.
Overtraining, such as a sudden increases in training loads or intensity, can lead to
shoulder pain if the swimmer continues to swim with fatigued muscles. As the
muscles fatigue they will work less efficiently which has two poor consequences.
First, the muscles have to work harder in a weakened condition. Second, the swimmer
has to perform more strokes to cover the same distance, which is overusing already
fatigued muscles. Together these two factors can result in swimmer's shoulder.
Unilateral breathing may also cause swimmer's shoulder. Swimmers who consistently
turn their heads to the same side to breathe are risking shoulder pain in the opposite
shoulder as it has to work harder to support forward movement with the head turned
to the side.
Furthermore, asymmetric body roll can increase impingement by causing a
compensatory crossover pull-through on the side with less roll. Improper head
position, forward-sloping shoulders, and shoulder blade instabilities are also
implicated in arm, shoulder, upper-back, and neck pain.
The use of hand paddles that are much larger than the swimmer's hand, or those
paddles that do not have drainage holes place great strain on the shoulder muscles
during the pull-through phase of freestyle. Using a kickboard with arms fully
extended in front of the swimmer can place the shoulder in a position of impingement.
The longer the swimmers uses these items, or uses them incorrectly, the greater the
risk of shoulder pain.
Other common causes of swimmer’s shoulder include: training errors (such as
unbalanced strength development), higher levels of swimming experience,
high percentage of freestyle swum in practices, weaknesses in the upper trapezius and
serratus anterior, weakness or tightness of the posterior cuff muscles (infraspinatus
and teres minor) and or a hyper mobile or very lax shoulder joint.
After all of this you probably ask yourself, what to do to prevent swimmers’
Fix incorrect technique
Core conditioning and flexibility
The following is a list of a few technique items you can work on.
Climbing the ladder. The early catch phase of the freestyle arm stroke may be
explained as a pinky- or fingers-first entry (not thumb-first) with water exit just above
the beltline. This technique will keep the swimmer in the impingement range for as
short a period as possible by avoiding excessive internal rotation. The stroke is a
straight line, not S-shaped. A good description is to imagine that a long stepladder is
just beneath the surface, and swimmers are trying to grab each rung and pull
themselves down the length of the ladder with equal body rotation. Paddling on
surfboards may help swimmers establish the correct hand pattern.
Rotating on the axis. The correct stroke pattern must be accompanied with equal
body rotation to avoid injury. The body must rotate at least 45° from its long axis
equally in both directions. The head position should be neutral on the spine as if the
person were standing on a flat surface in good alignment. The correct body roll should
feel as if one were rotating on a barbecue skewer that goes through the top, center of
the head and extends the length of the spine to between the ankles. Using a pull-buoy
(a foam device held between the thighs) or breathing every third stroke (or other
alternate pattern) can help a swimmer practice body rotation.
Floating the legs. The body's centre of mass is around the pubis (just below your
umbilicus), but the centre of buoyancy is at the sternum (breastbone). The lungs filled
with air float the body, but the mass and density of the legs tend to bring the body
down feet first. The swimmer must use the counterbalancing weight of the head and
press the centre of buoyancy (sternum) into the water to float the legs. Floating drills
with the hands at the side are the best way to learn this technique. Playing around with
the air in the lungs can help. Instead of focussing on breathing in, focus on breathing
out at once instead of all the way through the stroke. By keeping the air in the lungs,
the legs will stay closer to the surface.
Conditioning and flexibility. Shoulder injury is prevented first by core stabilization
and then by scapular stabilization. The scapula is the link in the kinetic chain from the
legs and trunk to the shoulder. Developing core strength from the pelvic girdle to the
scapular stabilizers is the common denominator to mastering all the previously talked
about skills. A good start are our pilates and yoga classes, where the abdominal and
shoulder muscles get a good workout.
Strengthening exercises should focus on endurance training of the serratus anterior,
lower trapezius, and subscapularis muscles.
The use of the upper-body ergometry can greatly enhance the endurance component
of the strengthening of the scapular stabilizers. The traditional rotator cuff elastic
band exercises are particularly effective for strengthening the external rotators.
Strengthening of the rotator-cuff muscles provides the best stability to the joint and
decreases the chance of hypermobility. Military press (shoulder press), side raise with
dumbbells (with external rotation), medicine ball exercises, lateral pull-downs and
seated rows are examples of a few. In addition the strengthen and lengthen program in
the back of the gym also provides some usefull exercises (dumbbel crucifix, standing
cable catch, and double or single internal rotation).
Strength training is most effective when done after swimming or as an isolated
workout session. Strengthening exercises done before swimming can fatigue the
rotator cuff and possibly increase the risk of injury.