Sports injuries: prevention and treatment of groin pain and the dreaded hernia
Understanding and dealing with hernia in sport
Sports hernia can strike athletes from all sporting backgrounds, yet is still a poorly understood condition. Alicia Filley sorts out fact from fiction and provides training activities to strengthen the pelvic region and keep the ‘bulge’ at bay.
A hernia is an out-pouching of organs or tissue from the abdominal cavity through a weakened or ruptured area in the abdominal wall musculature. A hernia can be caused by anything that increases the intra-abdominal pressure, like coughing or heavy lifting. A sportsman’s hernia, however, is more of a challenge to define.
Sportsman’s hernia, also known as athletic pubalgia, Gilmore’s groin, or incipient hernia, is a ‘catch-all’ phrase for undiagnosed chronic groin pain in athletes. Athletes may complain of groin pain for several months without recalling a specific mechanism of injury. The pain usually resolves with rest but resumes immediately with a return to sport. Conservative therapeutic management does not resolve the pain. Physical examination, however, does not typically reveal an actual hernia so there is little consensus among researchers or practitioners that sportsman’s hernias actually exist!
The groin is the area where the leg meets the trunk. This area, supported skeletally by the pelvis and femur, is where the transition of forces is greatest during athletic activities that require powerful starts, stops, and kicking, such as soccer and hockey. The pelvis is made of two bones that, along with the sacrum, form the bony ring of the lower trunk. At the front, the pelvic bones join together at the pubic symphysis joint (see figure 1).
The abdominal muscles of the trunk attach to the upper portion of the pubic bone. The rectus abdominis, the central-most abdominal muscle, originates as a broad, flat muscle and narrows significantly at its insertion on the pubis, causing a concentration of forces near the pubic symphysis joint. The adductor muscles of the thigh attach to the lower portion of the pubic bone. The largest of these muscles, the adductor longus, lies immediately below the rectus abdominis.
These two muscles share an aponeurosis, or fibrous covering, which connects the muscles to each other and the pubic bone. The adductor longus and rectus abdominis are antagonist muscles, with opposing force vectors generated by each. This opposition of forces, especially significant during sports that require kicking and powerful starts and stops, produces a constant strain at the pubic symphysis.
The other significant anatomical feature of the groin area is the presence of the inguinal canal. It runs between the layers of the anterior abdominal wall (made of the internal and external oblique muscles) and the posterior abdominal wall (composed of fascia and the conjoint tendon – the common tendon of the internal oblique and transverses muscles). The spermatic cord passes through the inguinal canal in males and the round ligament in females.
Theories of sports herniaTheory #1 – Athletic pubalgia, literally ‘pain in the pubic area’, is what some researchers and practitioners prefer to call chronic groin pain. The thought is that the pain originates from tears in the rectus abdominis or adductor longus tendons, or the common aponeurosis shared by both. Because these muscles function in opposite directions and share a common fibrous sheath, even a micro-tear in one of them will affect the function of the other. The resulting instability at the point in the pelvis where shear forces are the greatest further weakens other areas. (Note the close proximity of the inguinal canal to the lateral border of the rectus muscle.)
Seeking to standardise the diagnosis of athletic pubalgia, a group of radiologists from medical centres and universities around the world defined the radiographic parameters found on magnetic resonance imaging (MRI) in patients with athletic pubalgia. Recent advances in MRI have allowed visualisation of an injury to the lateral border of the rectus not previously noted(1). The physicians observed this tearing in varying degrees among patients, from minimal tears in one muscle to complete tears in both the rectus and adductor longus muscles. MRI rarely revealed a true hernia in these patients.
These practitioners theorise that hernia-like symptoms arise from the proximity of the rectus to the inguinal canal. They also suggest that once a weakening of either the rectus abdominis or the adductor longus muscles compromises the stability of the pelvis, a strain can occur in the other muscles that try to provide compensatory stability. Since there are indeed many other syndromes that manifest as groin pain, a general screening MRI is recommended to rule out other issues. If none arises, then these physicians recommend a detailed MRI study of the pubic symphysis.
Theory #2 – At the department of surgery at Drexel University in Philadelphia, Pennsylvania, physicians examined two decades of sports hernia patient records and noted trends in both diagnosis and treatment. They report that currently, they see ten times the number of patients in clinic for sports hernias than they did 20 years ago(2). They also agree that sports hernia is a misnomer; they perform few actual hernia repairs on patients who present with chronic groin pain.
These practitioners found that chronic groin pain stems from disruption of many of the muscles within the pubic complex. In 2006 they examined the MRIs of 100 consecutive patients with athletic pubalgia(3). The results showed defects in not only the rectus abdominis and adductor longus muscles, but also the pubic joint, the other adductor muscles of the leg, and even the hip (see table 1).
Theory #3 – Theories 1 and 2 centre around defects in the pubis and adductor muscles of the leg. However, at the University of Insubria in Italy, one researcher sites a different origin for the chronic groin pain experienced by many athletes. Campanelli postulates that because the adductor muscles are usually stronger than the abdominal muscles, the shear forces that cross the pelvis in sports like soccer result in a tearing or weakening of the muscles and fascia in the posterior abdominal wall(4). This surgeon prefers to refer to chronic groin pain as pubic inguinal pain syndrome (PIP).
The reason Campanelli’s nomenclature differs is that he agrees with studies that show surgical findings of posterior abdominal wall defects in 80-100% of the cases of groin pain(4). The experience of his surgical centre shows that there are usually additional defects in the rectus abdominis and external oblique muscles as well. The muscle defects in this area impact the nerves that pass through the inguinal region and result in a dilated and stiff external inguinal ring.
Where’s the hernia?
Groin pain specialists in Sydney, Australia think they finally located the elusive sports hernia. They agree that the underlying mechanism of injury is the imbalance of opposing muscles that results in pelvic instability. However, they prefer to think of chronic groin pain as a groin disruption injury, which encompasses all of the above theories(3).
This theory is that when athletes endure repeated loading and stress to the pubic symphysis, the joint eventually degenerates, creating an unstable pelvis. This instability leaves the surrounding musculature vulnerable to stress and strain. The strain first manifests as micro-tears where the tendons attach to the pelvis, then progresses to more significant tears within the muscles. The resulting weakness in the posterior abdominal wall muscles leads to a sportsman’s hernia (see figure 2).
According to these groin pain specialists, the elusive sportsman’s hernia is a dynamic phenomenon. To visualise it, you must conduct a real-time imaging study, such as an ultrasound, computed tomography (CT) or MRI while the patient actively strains, as in an abdominal crunch. If a mild bulge is seen in the posterior abdominal wall, there is usually an associated lesion in the conjoint tendon of the inguinal canal. While not felt on clinical examination, these real time images provide proof that there can be, at perhaps the end of a continuum of injury, a real hernia in the posterior abdominal wall when straining.
Sportsman’s hernia is most commonly diagnosed in soccer, hockey and Australian football players with chronic groin pain. These sports carry an inherent risk in the sudden starts, stops, changes in direction and kicking that they demand. However, there are some underlying biomechanical issues that may predispose an athlete to suffering a groin disruption injury.
The first is a leg length discrepancy. If one limb is just five millimetres shorter than the other, it increases the ground reaction forces the pelvis must endure(3). Leg length differences are easily treated with orthotics.
Tightness in the internal and external rotation of the hip joint is another risk factor. A previous groin injury also increases the risk that an athlete will suffer another one. And muscle imbalances around the pelvic and hip joints increase the risk of chronic groin pain.
When an athlete presents with groin pain, conservative measures are always implemented first. The typical course of treatment includes ice, rest, stretching, strengthening and physiotherapy. If the injury lies somewhere along the continuum of a groin disruption injury, the pain will improve initially and return once the athlete returns to normal training activities. Groin pain that persists for more than six months and does not respond to conservative measures is the hallmark of this syndrome and is usually treated surgically.
There are as many surgical approaches to treatment as there are theories to the cause of chronic groin pain. The treatment studies reported in the medical literature are Level IV studies, which means they are largely case series reports without any controls and with poor reference standards. Despite the variability in the surgical approaches, these studies typically report good outcomes and return to play statistics ranging from 77% to 100%(5).
Keeping in mind that these are case series studies, it is still interesting to consider that whether someone performs a repair to the rectus and adductor muscles or a hernia repair with surgical mesh placed along the posterior abdominal wall, the evidence suggests that the athlete usually benefits. No matter where the athlete is along the continuum of injury, repairing any part of the pubic complex seems to result in at least some improvement in pelvic stability. That said, recurrent groin pain is not unusual and athletes may need to visit a surgeon with a different speciality if the pain returns. Regardless of the type of surgical repair, most athletes return to play in three to six months.
With the recent advances in MRI and real-time imaging, there may be some standardisation in the diagnosis of chronic groin pain in the near future and the repairs implemented should become more individualised. Given that there is a progression of injury, there should not be a ‘one size fits all’ procedure for every athlete who has groin pain.
If you play soccer, hockey, or Australian football, you are already at high risk for a groin disruption injury. Leg length disparity is also a significant risk factor. Therefore, everyone playing these sports should consult with a physiotherapist for leg length measurements. Even small differences can make you more vulnerable to injury.
The best way to minimise your risk is through stretching and strengthening the core musculature around the pelvis and the adductor muscles of the thigh. Pilates and yoga address both flexibility and strength and should be an integral part of your off-season training. If you are new to these exercise techniques, train with a qualified instructor until you have mastered the basics. Simple exercises using a band at home can also make a great impact on your strength in these areas (see figures 3-5, above).
Historically, sportsman’s hernia was a diagnosis of exclusion. Recent medical diagnostic imaging now reveals that sportsman’s hernias do exist and can be reliably diagnosed with real-time imaging that corresponds with a history and physical exam. The hernia, however, is not the end of the story.
There is a continuum of injury within the pubic complex that results from an imbalance in the pubic musculature, namely the rectus abdominis and the adductor longus. It is this imbalance that leads to injury and weakness of the posterior abdominal wall and thus, the hernia. When groin pain lasts more than six months and does not respond to conservative treatment, surgery is usually indicated. The surgical management technique often reflects the speciality of the physician, rather than the actually diagnosed impairments.
As diagnostic imaging becomes more standardised, management should become more individualised to the patient. Surgical results are often excellent, with most returning to previous level of play within three to six months. Knowing your risk factors and integrating appropriate off-season core training should improve your standing in the battle of the bulge.
Alicia Filley, PT, MS, PCS, lives in Houston, Texas and is vice president of Eubiotics: The Science of Healthy Living, which provides counselling for those seeking to improve their health, fitness or athletic performance through exercise and nutrition
1. Radiographics. 2008;28(5):1415-1438
2. Ann Surg. 2008 Oct;248(4):656-665
3. Hernia. 2010;14:17-25
4. Hernia. 2010;14:1-4
5. Curr Sports Med Rep. 2007;6:111-114
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