Rib injuries in swimmers: a pain in the chest you really should avoid!

During the front crawl (also referred to as freestyle) technique, a swimmer will use either a unilateral (breathing to one side) or a bilateral (breathing to either sides) breathing technique. A unilateral breathing approach increases the loading to one side, usually towards the dominant side, through rotation of the mid back and trunk onto one side.

It’s hard to argue against the use of a bilateral approach in terms of body symmetry. However, a unilateral approach is not necessarily incorrect, and many elite swimmers breathe unilaterally. But unilateral breathing may increase the risk of chest muscle pain in vulnerable swimmers. This is because at the point the arm enters the water, the shoulder and arm complex is raised over head with the ribs expanded and ready to exhale (following a breath of inspiration). To apply the ‘pull’ through the water, the pectoralis major muscles of the chest and latissimus dorsi muscles of the back engage to apply to the force to propel the body past the point where the arm entered the water.

During the front crawl swimming stroke cycle, the thoracic spine (the mid back) initiates full body rotation and is required to rotate to allow for the arm to exit the water and reach forwards ready to re-enter the water (see figure 1)^{Clini J of Sports Med, 1995, 5, 254-257.}. Because the ribs connect directly to the thoracic region, the demands placed on the ribs and mid back are greater than other strokes such as breast stroke and butterfly, where the forces are equally distributed across both the left and right side of the trunk. That isn’t to say that the swimmers training using primarily butterfly, backstroke or breaststroke (see figure 2) don’t ever suffer from chest or rib injuries. However a lot of the research that has been published relating to these types of injuries in swimming has been carried out on front crawl swimmers and therefore this article will focus more on the front crawl technique.

FIGURE 1: TRUNK ROTATION DURING THE FRONT CRAWL TECHNIQUE

FIGURE 2: BREAST STROKE DURING THE PROPULSION PHASE

Different chest-related injuries

*Costochondritis - A variety of injuries can occur to the front of the chest wall as a result of the swimming stroke. One example is ‘costochondritis’, which is inflammation of the cartilage in the costochondral rib joint. This is where the rib connects with the sternum - better known as the breast bone in the centre of the chest (see figure 3), and is more commonly diagnosed in females^{J Can Chiropr Assoc, 2010, Dec, 54, 4, 271–275.}. Unfortunately, this is a poorly-recognised condition within the field of sports physiotherapy, which means that it may go undiagnosed when a swimmer seeks help after experiencing rib aches and pains.

*Stress fracture - The majority of stress fractures occur in lower-limb sports that are running based. Rib stress fractures are less common but do occur in wrestling, dancing, squash, baseball, rowing and basketball^{Clini J of Sports Med, 1995, 5, 254-257.}. When they do occur, they are most likely to affect the first rib, and as a consequence of throwing and overhead arm actions. However, the trunk and body rotation in front crawl swimming, combined with the overhead action means that lower rib stress fracture can also occur in swimmers undergoing heavy training loads.

FIGURE 3: COSTOCHONDRITIS OF THE RIBS (VIEWED FROM THE FRONT)

In addition, chronic coughing, excessive lifting and physical labour can be contributing factors in the occurrence of rib stress fractures, as can heavy load lifting performed with incorrect technique. Research shows that all other things (such as training loads) being equal, females are more susceptible to stress fracture. This increased risk is mainly due to menstrual and hormonal factors, lower bone density and bone width, and also biomechanical differences^{Clini J of Sports Med, 1995, 5, 254-257.}. Secondary factors, other than exercise, that may contribute to stress factors include low levels of vitamin D, hyperthyroidism and Cushing syndrome.

Slipping-rib syndrome

Slipping-rib syndrome is a condition produced by increased mobility of the 8th, 9th and 10th ribs at the front of the rib cage due to a weakness in the connective tissue covering these structures (see figure 4) ^{Clinical Pediatrics, Sept, 1996, 35, 8, 403-5.}. The increased mobility of the ribs in this area occurs because these ribs don’t attach to the breastbone, but are instead simply connected to each other by a fibrous band – hence their common terminology ‘false ribs’). This increased movement can apply pressure to the intercostal nerve, which then radiates pain to the abdomen or the anterior chest wall^{Clinical Pediatrics, Sept, 1996, 35, 8, 403-5.}. This condition is often under or misdiagnosed and has been variously referred to in the literature as ‘clicking rib’, ‘painful rib syndrome’, ‘traumatic intercostal neuritis’, ‘rib-tip syndrome’ and ‘slipping-rib cartilage syndrome’^{J of Ath Train, 2005, 40, 2, 120-122.}

FIGURE 4: SLIPPING RIB SYNDROME

Symptoms of rib-related injuries

The first thing to say is that if you are experiencing rib or chest pain then it is essential to be examined by a doctor to rule out anything more serious such as a heart or lung-related condition. Costochondritis is often caused by an increased pull of the pectoral muscles on this region of the body. The typical symptoms are tenderness on the costochondral joint (see figure 3) but without any swelling. It may be useful to identify any differences in strength between the left and right sides as this may predispose you to increased stress in the chest on the more dominant side of the body. A stress fracture of a rib typically presents as a progressive dull ache in the back of the shoulder or the upper back. When the site of the stress fracture injury is palpated (pressed), a sharp pain is felt. A stress fracture can be confirmed with an X-ray, although a CT scan is more accurate for diagnosis^{Am J of Sports Med, 2005, 33, 9, 1400 – 1404.}.

CASE STUDY: Slipped rib in a collegiate swimmer

Amelia (name changed for privacy purposes) is a 23-year-old collegiate female swimmer who recently experienced a nine-month history of single-sided lower rib pain, which turned out to be slippingrib syndrome. Amelia was warming up prior to a race, swinging her arms above her head when she suddenly experienced mild pain in the lower rib cage. The pain persisted and was especially apparent during movements that produced compression at the front, back and side – eg sit ups. In particular, the pain was focussed between the 8th and 12th ribs, with pain also radiating into her lower back. However, there was no swelling, deformity or bruising in her lower rib cage.

After nine months of symptoms and multiple unsuccessful visits to the physiotherapy department and assessments by doctors, a surgeon suspected slipping rib syndrome. Surgery was carried out to reattach the 11th rib to the 10th rib above. After six weeks of relative inactivity post surgery, Amelia started some core exercises and light pool work. After eight weeks, she was able to increase her pool work to 2000 yards per day which progressed to 6000 yards at twelve weeks with mild discomfort. Six months after her surgery, Amelia was competing at the national swimming championships, and was completely pain free.

Rehabilitation exercises

If you have been diagnosed with a rib stress fracture, costochondritis or slipping rib syndrome then it is desirable to refrain from swimming or any aggravating activities until your symptoms have subsided. In the meantime, it is effective to ice, foam roll the mid back muscles and to undertake a variety of exercises to improve trunk mobility and to prepare the body for a return to activity (see figure 5). As the symptoms settle, the exercise load can be progressively increased to include some resisted trunk rotation and to include the upper body bike (figure 6). The upper body bike is great to start when pain free to include some controlled upper body resistance training but with a cardiovascular element using both a forward and backward rotation to replicate the demands of front crawl and back stroke.

FIGURE 5: PREPARING FOR ACTIVITY

A) Foam rolling the mid back muscles to reduce muscle tension for improved joint mobility in the mid back (to allow better trunk rotation to occur); B) Trunk rotation lying on the back; C) Superman exercise; D) Pectoral stretch using a door frame

FIGURE 6: BUILDING ACTIVITY

A) Resisted trunk rotation; B) Upper body bike using forward and backward rotations; C) Trunk rotation to stretch the trunk muscles

Prevention strategies

It is useful to implement strategies that not only help prevent chest related injuries but that will also improve and optimise overall performance. The key elements of prevention are:

• Appropriate strength and conditioning
• Adequate recovery
• Correct technique, focusing on stroke execution.

It is very easy to talk about strength and conditioning and to simply select some common exercises such as press ups. But what matters is how functional these exercises are to the demands of swimming. Therefore it is important to focus on exercises that challenge the muscles related to swimming - not only from a strength perspective but also in terms of movement function.

The exercises in figures 5 and 6 are still very relevant for prevention but should be progressed where possible. The use of suspension cables is a great way to do this and provide functional loading to replicate some of the demands of swimming. See figure 7, which provides some examples.

It’s also important to eliminate some common technique errors that may predispose to a chest wall injury. A correct angle at the elbow during propulsion is essential, which should also present with the hand in line with the shoulder, and not crossing the midline of the body (see figure 8). A straight arm not only increases the load at the shoulder joint, but also at the chest wall. If the arm crosses the midline of the body at the point of entry, it increases the side to side movement of the legs. This increases the stress on the spine and as well as single-side loading onto the chest wall.

FIGURE 7: FUNCTIONAL CONDITIONING EXERCISES FOR INJURY PREVENTION

In terms of reps and sets it is essential to not pause after each repetititon and to keep moving throughout. Aim 10-20 repetitions over 2-4 sets. Ensure you maintain good trunk alignment as you work to fatigue. Don’t compromise technique as this could transfer into your swimming stroke.

FIGURE 8: ELBOW ANGLE AND ARM ALIGNMENT