There are many different causes of abdominal pain, but despite being quite common, there is little written about abdominal pain from a musculoskeletal perspective. Read on as we discuss some of the more common musculoskeletal disorders.
Incipient (Sportsman’s) Hernia
The various muscles of the abdominal wall are penetrated by the inguinal canal, which contains nerves and, in men, the spermatic cord. In women, the inguinal canal contains a small fibrous ligament. Where the inguinal canal penetrates the abdominal wall, weak spots arise, and this is the site of an incipient inguinal hernia. It is effectively a tear of the muscles and connective tissue in the area.
There is some debate in the literature as to how this is diagnosed, but the symptoms include the following:
- Lower abdominal pain
- Stiffness or soreness after training
- Groin pain that is increased by running, sprinting, twisting and turning
- Groin pain that is increased when coughing, sneezing, etc.
It is claimed that in 30 percent of athletes, there is a history of sudden injury, but the majority indicate an incipient hernia is a gradual overuse injury.
It depends upon the skills of the doctor or therapist as to whether a sportsman’s hernia can be diagnosed, but this problem accounts for many of the unsuccessfully treated abdominal and groin injuries seen in sports today. If any of your clients complain of the above types of symptoms, one of the main areas to check first is the sacro-iliac (SI) joint function.
If there is an abnormal positioning of the SI joint, this can increase the load on the external and internal obliques and consequently the inguinal canal, causing damage. So before trying to manage the hernia, you need to try to correct any biomechanical causes that may be loading the area. The two best tests to check for correct biomechanical function of the pelvis are Downing’s sign and the 4-sign (Patrick Fabre’s sign). This is according to Barrow and Haines when they biomechanically tested over 4,000 people to look at which manual tests had the highest correlation with the biomechanical tests in the lab for establishing pelvic function.
Downing’s sign is a non weight bearing test and also establishes whether there is a functional or apparent leg length discrepancy. To perform this test, have your client lie supine, ask him to bridge, then lift his knees to his chest and then straighten his legs out to the floor. At this point, measure any difference in height between his medial malleoli. Then, move his hips by taking them passively into adduction then flexion, then abduction and then into extension. Then take a look at the heights of his medial malleolus. If his pelvis is working correctly, that leg should have lengthened, and the malleolus on that side should be lower. Reverse the movement, and when you now measure the medial maleolus height, that leg should have shortened again, making the leg lengths the same as they were after they bridged. Try it on both sides. If the legs lengthen and shorten, the pelvis is working correctly. If they don’t, then the pelvis is dysfunctional and can be loading the hernia area.
The 4-sign (Patrick Fabre’s sign) is usually applied clinically rather than biomechanically. With this test, have your client lie supine (or you can do it seated) and cross one leg over the other with the lateral malleolus placed on the lower quad of the opposite leg. Look at how low the knee drops to the floor or mat. Then repeat on the other side. They should be symmetrical. If they aren’t symmetrical, then the pelvis is dysfunctional.
In addition, if the pelvis is abnormally rotated, as well as causing a functional leg length discrepancy, it can increase the load on the symphasis pubis, which can also refer pain into the lower abdominals. The best way to mobilize the pelvis and correct any SI dysfunction through exercise is to perform anti-spasm exercises (a form of hold-relax exercise) for the hip extensors and specifically glutes and piriformis. Once the pelvis is in good biomechanical shape, then core work can help to stabilize it. Also, work on the scar tissue around the inguinal canal to help the healing. When your client is ready, you can progress on to the functional stability work. It is critical that you work the adductors of the hip as well. This is because the adductors and the trunk muscles work closely to control and stabilize the pelvis, and for men especially, their adductors are often “weak” or inhibited. This may be one of the reasons that they have the incipient hernia in the first place.
While today the latest trend is “functional movements,” there are times in rehab and conditioning when you need to isolate muscles first, and this is one example. As Mark Verstegen says: “First isolate, then integrate.” Working the hip adductors symmetrically in the seated adductor machine helps engage the adductors (and core when positioned correctly) and mobilize the symphasis pubis. Then progressing to asymmetrical adductor work on the total hip machine (hip conditioner) will introduce a more weight-bearing challenge with additional torque through the pelvis, and furthermore, functional movements can be a very effective way of integrating the pelvic and trunk musculature.
The problem with functional movements, in this example, is that if one of the muscles is not firing correctly or is inhibited (in this case, the adductors), and you do functional training for the hip and trunk, the body is a master of compensation, and other muscles can take over to protect it. The muscle needs to be “taught” how to contract and fire again, so it is able to be integrated in a functional pattern of movement. So in this case (as with many others), isolate then integrate.
More often than not, the incipient hernias can be managed through exercise rather than surgery. Just try to make sure you correct the mechanical faults with the pelvis as well as strengthening the obliques.
Separated Rectus Abdominus (Diastasis Recti)
While this condition is not an injury, it is worth discussing it here as part of a discussion on abdominal issues. Diastasis recti is a separation between the left and right side of the rectus abdominus muscle, which covers the front surface of the belly area. Another name for the more commonly described separated rectus abdominus, it is usually caused by pregnancy and the rectus muscle being stretched by the baby in the uterus. This condition is most common in the later trimesters and more so with multiple births or repeated pregnancies.
A diastasis recti looks like a ridge that runs down the middle of the abdominals. It stretches from the sternum to the navel and increases with abdominal muscle contraction. In the later part of pregnancy and in extreme cases, the top of the pregnant uterus can be seen bulging out of the abdominal wall when the rectus is engaged. Post natally, to check if your client has diastasis recti, have her lie supine with knees bent and ask her to raise her head. You commonly see a central ridge protrude in the center of rectus abdominus, and if you carefully palpate above the navel, you should feel a soft gap between two hard muscles. Measure the space of the gap using your fingers (this is called a rec check). If the gap is greater than two finger-widths, your client may be suffering from separated muscles.
No treatment as such will help pregnant women with this condition, although exercise may help, but there is limited evidence that exercise will resolve the problem. However, post natally, conventional wisdom suggests that after any discomfort has settled, it is reasonable to start some light abdominal work. However, do not work the obliques initially.
Understanding their origin and insertions reveals any oblique contraction will most likely exaggerate the split of rectus. Start with pelvic floor work and stabilizing work using TA with the pelvis in the correct position, then do co-activation work with pelvic floor and then progress to try to shorten the rectus by doing inner range work. Please note that the production of relaxin (a hormone that is secreted in abundance in pregnancy) affects the collagen make up in the linae alba (the central tendon in rectus abdominus) and may be a cause of the diastasis. As soon as the placenta is delivered, the increased secretion of relaxin reduces to normal. At this point, another hormone called prolactin is secreted. Prolactin has the same effect as relaxin and can last for up to five months. Breastfeeding will keep it higher than normal until your client has stopped. This may affect how quickly the diastasis recti will reduce.
Please also be careful while working the transverse abdominus. While conventional wisdom is sometimes right, it sometimes isn’t! Let’s challenge it now. If you look at the origin and insertion of the transverse abdominus and consider its function, logically when it contracts it will pull the rectus apart further, much the same as contracting the obliques would. There is no evidence to suggest that doing TA work is the right thing to do. It’s just something that we all do without much thought as to why. Just think, if the TA inserts into the aponeurosis of rectus (anteriorly below the navel and posteriorly above the navel), any TA contraction should pull the rectus apart further.
So why do we work TA initially with a diastasis recti? Are we suggesting going back to the days of doing sit ups? Not necessarily, but more work needs to be done before we know working TA is right for ladies in the early stages of diastasis recti.
Referred Abdominal Pain
Referred pain is a term used to describe the phenomenon of pain perceived at a site adjacent to or at a distance from the site of an injury’s origin. The International Association for the Study of Pain, as of 2001, has not officially defined the term, so several authors have defined the term differently. Despite an increasing amount of literature on the subject, there is no definitive answer regarding the mechanism behind this phenomenon. Physicians and scientists have known about referred pain since the late 1880s, yet the true origins and causes of referred pain are unknown. However, we do know that referred pain can come from a number of areas, like the thorax (pneumonia, pulmonary embolism, ischemic heart disease and pericarditis), the spine (radiculitis) and from the genitals (testicular torsion).
So if you have any uncertainty at all, refer your client to a relevant medical specialist. If you think there may be some cardiac involvement, refer to a cardiologist, and if you are concerned that the pain may be referred from the spine, then any good manual therapist should be able to help. Don’t worry too much about whether it’s a physiotherapist, osteopath or chiropractor. Consider the person rather than the qualification. Try to find one who understands biomechanics so he/she can work out why your client has the pain and also find someone who understands exercise and is prepared to discuss the science with you to come to a logical conclusion.
As long as there is no underlying clinical pathology, exercise is an excellent way of managing musculoskeletal-related abdominal pain and its many causes. The key is to identify the biomechanical causes (rotated pelvis, weak or inhibited adductors, tight lumbar spine, tight thoracic spine etc) and manage them. Then if you progressively condition the relevant muscles, the abdominal pain usually looks after itself.
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