Gauging Groin Pain

Groin pain can be caused by numerous injuries and conditions. Here are ways to diagnose and treat this condition.

By Jodie Humphrey

Jodie Humphrey, PT, ATC, CSCS, is a physical therapist at South Coast Rehabilitation in New Bedford, Mass., and has worked as an athletic trainer for the University of Massachusetts, Dartmouth College, and Northeastern University.

Training & Conditioning, 11.7, October 2001, http://www.momentummedia.com/articles/tc/tc1107/groinpain.htm

An injured athlete comes into your athletic training room complaining of persistent groin pain that started the morning after an early-season hockey game. Is it a strain? Could a muscle be torn? Perhaps it's a compensation injury. In the case of a groin pull or groin pain, finding the answers to these questions can be complicated.

When athletes complain of groin pulls or strains, they are using a vague, general term that commonly describes pain in the medial femoral region. In most cases, a groin pull refers to an adductor strain, but it can also include an array of other soft tissue or joint mobility problems in the pelvic area. For these reasons, groin injuries can be difficult to diagnose.

An issue that further complicates the diagnosis of a groin injury is, unlike the immediate pain caused by a severe joint strain, the onset of groin pull symptoms typically occurs several minutes, or even hours, after the conclusion of a sporting event. As an athletic trainer facing this situation, you have to determine if the tissue producing symptoms is a muscle, bone, ligament, nerve, bursa, or, possibly, a systemic condition.

WHAT'S THE PROBLEM?
If you are treating someone with groin pain, ask yourself the following questions:
What happened that made the strain occur?
Was a muscle too weak?
Did the athlete have poor endurance?
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One important point to consider during diagnosis is the fact that muscle groups and joints are not isolated. They are interconnected and rely on other regions working in synchronization to do their job. When the body goes out of sync, an injury in one area can cause pain in another area. For example, if someone walks on the outside of his or her foot because the big toe is injured, the force of supporting and moving the body is altered throughout the lower kinetic chain. As a result, the excess ground reaction forces will be transferred up to the hip, which in turn alters mechanics at the joint and eventually causes pain in the hip and groin areas. Therefore, the location of pain and the site of injury are not always the same.

BIOMECHANICAL CONSIDERATIONS
If the pelvic area is determined as the source of injury, it is important to understand that there must be a dynamic balance between muscles for the pelvic girdle to be stabilized and to function without pain or injury. Imbalances of the musculature cause injury and pain. Healthy muscle has the practical ability to produce tension, partly due to its contractile force and partly due to the resistance of its connective tissue components to stretch. Once this capacity is exceeded due to an imbalance or trauma, a strain occurs, disrupting the muscle, connective tissue, multiple motor units, the vascular supply, lymphatic ducts, and so on.

The nerve and muscle spindle, collectively called the motor unit, interact to fine tune the muscle contraction to meet the necessary force production. Consequently, one of the first considerations is to look for an imbalance or lack of dynamic stability of muscle groups while your athlete performs a specific drill. For example, consider the analysis of a box jump in plyometrics for its quality of movement. If you watch the athlete closely during this exercise, you might observe the tight hip flexors causing hyperextension at the lumbar spine during the push-off phase to jump onto the box. Weak hip extensors may be hidden by a powerful gastrocnemius push off from the floor. If the athlete's knees fall inward at the landing phase, the problem may be weak hip external rotators and hip abductors.

Researchers such as A.C. Merchant have found that tensor fasciae latae produces 50 percent of the necessary force to maintain proper alignment when the hip is externally rotated by 30 degrees. Once the hip is internally rotated, the tensor does not work at all. Therefore, if the tensor and hip abductors cannot counteract the necessary force to keep the hips externally rotated, then there is a high likelihood of a dynamic weakness in this muscle group, which will cause groin pain.

In addition to assessing the dynamic capacity of the muscles that act on the hip and pelvic area, it is important to evaluate them for flexibility, strength, endurance, soft tissue mobility, and tissue density. The strength of the muscle must be considered in its full arc of movement. The break test, which is commonly used, allows other muscle fibers to be recruited to compensate for force production loss, giving a partial measure of strength. Lastly, the pelvic floor muscles, especially in females, need to be considered as a potential source or weak link to the pelvic unit manifesting as pain in the groin region.

An athletic trainer who is assessing an athlete's groin injury must consider all of the muscle groups working in synchronization. Considering the synchronization of these muscle groups is a necessary step in addressing groin pain, because any musculature imbalance will create such pain.

OTHER SOURCES OF PAIN
If the musculature is ruled out as the source of groin pain, there are numerous other options to consider. For example, the ligaments and capsules of the hip and sacroiliac joints are common underlying causes of groin pain and injuries. Examples of injuries that can be caused by trauma to these structures include acetabular labral tears, iliopectineal bursitis, inguinal or femoral hernia, and anterior capsule strains. The anterior capsule can be inflamed from excess impact, especially during high-impact sports. This anterior capsule irritation can cause inner groin pain. Moreover, the hormonal fluctuations associated with a woman's menstrual cycle may diminish the effectiveness of the hip's static stabilizers, thereby increasing the need for dynamic muscular stabilization. Finally, sacroiliac dysfunction commonly leads to inner groin pain, and should be considered during diagnosis and management.

Another consideration is a neuromuscular cause of groin pain. The communication within the nervous system can be distorted when a nerve ending is injured, entrapped, or when nerve function is otherwise disrupted. Muscle strains, contusions, overuse problems, and other trauma can cause this neuromuscular disruption. The nerve network in the pelvic area needs to move freely in the pelvic cavity, where it is held in place by, and passes through, several muscles. Inappropriate neural impulses could initiate the sense of pain in a healthy muscle if the nerve network is injured or disrupted by producing a referred pain response.

The probability of bony trauma, such as an avulsion fracture, stress fracture, or exostosis, would produce a constant ache and point tenderness. Bony pathology may also be congenital, as in the case of Legg-Calve-Perthes disease, slipped capital femoral epiphysis, or rheumatoid arthritis. Athletic pubalgia, which is constant microstresses of the pubic symphysis, can cause pain in the coxofemoral joint that radiates into the medial and lateral thigh.

There also is a variety of systemic problems that can elicit groin pain as well. If the problem does not seem musculoskeletal, if it causes pain without relation to sport activities, and if it is painful at night, then consider testicular cancer, fibroids, or sexually transmitted diseases.

MANAGEMENT APPROACHES
The treatments for groin pain are almost as varied as the causes. As an athletic trainer, your understanding of the biomechanics of sports and the forces that cause injuries can help dictate proper treatment of groin pain. Once you identify the cause of an athlete's groin pain, you must select the proper management approach for that particular patient. One treatment approach may not be enough to adequately get the athlete back to play. I will divide the management approaches into four major categories of groin injuries: muscular trauma, ligamentous/capsular damage, neurological sources, and systemic causes.

Muscular Trauma
Muscular trauma is the most common cause of groin injury and therefore, it receives the most detail in this article. Soft tissue mobilization is the common approach for treating muscular trauma. Here are several common categories and the proper management approach:

Travell and Simmons's Myo-fascial Pain and Dysfunction: Referred pain patterns, particularly from pectineus, vastus medialis, gracilis, adductor magnus, and sartorius, can produce medial thigh pain. A common approach for referred pain from trigger points in these muscles is to institute spray and stretch techniques, along with instructing corrective posture, body mechanics, exercises, and home therapeutic programs to treat any active trigger points causing pain.

Jones' strain-counterstrain is a manual technique that also involves trigger points. The muscle is shortened for a period of 90 seconds to quiet the active trigger point that is causing tension on the soft tissues, which, in turn, is causing the pain.

Deep friction massage is another approach that lessens the tissue density in cases where stretching muscles longitudinally is ineffective. Remember, the muscle fibers and connective tissue need to be mobilized apart to restore normal muscle function.

Flexibility exercise is one management approach to muscular trauma that can facilitate healing, but can also damage the muscle that is under repair. If performed too aggressively, the shear force of static stretching at the motor unit can be detrimental to the delicate nerve regeneration and muscle healing. Generally, a mild soreness is acceptable, but symptoms should cease upon termination of the hold of the stretch. A dynamic stretching routine, rather than static stretching, is a good starting point. An example of dynamic stretching of the hip adductors would be pendulum-style leg swings into abduction-adduction and flexion-extension with an extended knee. Another exercise is a lateral step with a squat (see "Functional Flexibility" in the July/August issue of Training & Conditioning for more information about dynamic stretching).

Deep friction, petrissage, rolfing, and other massage techniques can also provide valuable feedback from the damaged tissues. Once the treatment is performed, the clinician can confirm the origin of the injury by feeling the heat from inflammation arising from the soft tissues, and also get a sense of the tissue density involved in the groin injury that needs to be remedied.

Therapeutic exercise is another useful approach to groin injuries caused by muscular trauma. When therapeutic exercise is performed, the load demanded of the muscle should be gradually increased to stress the muscle to heal with proper matrix formation. In the first three to five days after an acute trauma, the athletic trainer should use caution to not disrupt tissue healing during the acute to subacute phase. Disrupting this healing phase will impede the athlete's recovery. Consequently, the load, sets and repetitions need to be carefully progressed and symptoms should be monitored before, during, and after exercising.

A good place to start when an athlete's injury is in an acute phase would be to use gravity-assisted active range of motion, which puts minimal stress on the healing tissue. For a strain of the adductor group, a sidelying abduction and hip extension would be a gentle start. If sidelying adduction is performed in the acute injury phase, the repetitions should be low (fewer than 10) with one to three sets performed.

In order to re-train the damaged tissues appropriately, you should emphasize quality over quantity during therapeutic exercise. This means the technique of the exercise should not be compensated to achieve a desired number of repetitions. The athlete should not experience any pain beyond that caused by the injury itself. A soreness that resolves quickly or after ice application is generally fine, but therapeutic exercise shouldn't cause lingering discomfort. In the hip, flexion or rotation at the joint can greatly alter the workload of the desired muscle involved to perform the work.

Ligamentous/Capsular Damage
For ligamentous/capsular damage, joint mobilization techniques to facilitate arthrokinematics of the hip, sacroiliac joint, lower lumbar spine, and knee can assist in proper healing of a groin injury. Muscle energy techniques are at the forefront for pelvic dysfunction in today's literature. As the ligaments and capsule heal, scar tissue builds up, but the amount of scar tissue needs to be controlled to restore normal function and stability to the joint capsule and ligaments. In some cases, damage to one of the passive restraints may require surgical intervention, since these tissues have a poor repair potential. Treatment should focus on a series of proprioceptive exercises to enhance stabilization, while working the hip and pelvic muscles. For example, bridging with a long arc quad or upper extremity resistance while unilateral standing is helpful.

Neurological Sources
Consider all of the stimuli that can produce painful nerve impulses. The identification of the offending stimuli greatly aids in the choice of treatment of the damaged neuromuscular connection. Painful impulses can be caused by a mechanical or chemical irritation of nociceptors. Possible pain triggers include temperature, cytokines, catecholomines, decreased blood flow and other metabolic factors, and mechanical pressure from swelling, muscle spasm, or other forms of nerve impingement.

Modalities can be effective tools for hastening neuromuscular healing. The choice and timing of these modalities should be determined by the tissue that is damaged and the phase of recovery. The following modalities have proven effective in the treatment of groin injuries arising from neuromuscular sources:

Electrical stimulation is best used as a muscle re-educator, but interferential electrical stimulation is also effective for pain modulation and the management of swelling. The best time to implement electrical stimulation is during the subacute or chronic phase of recovery.

Ultrasound. This treatment regime can be effective for many athletes. However, be sure to follow appropriate parameters and application.

Heat therapy. The use of the heat therapy modality can vary depending on the tissue involved. For muscle, the heat can assist in increasing muscle repair by assisting blood flow. Damaged nerve endings may respond poorly to the heat application. However, the use of an internal heating method, such as gentle exercise or soft tissue mobilization, can work just as effectively.

Cold therapy is an effective modality that is best used throughout the injury recovery process, and applied frequently.

Systemic
Treatment of the orthopedic manifestations of systemic disease should focus on symptomatic relief and maintaining proper biomechanics, gait, and posture. Adequate nutrition, hydration, and cardiovascular conditioning are required for normal tissue healing. The contraindications caused by the systemic disease must be considered when selecting therapeutic modalities and determining therapeutic exercise routines. The aquatic environment may be the safest avenue for relieving the symptoms while a patient's diagnostic workup is conducted.

Given the numerous interrelated conditions that can cause groin pain, the job of diagnosing and treating this condition is a challenge. This article hopefully provides a framework within which you can apply your skills when treating athletes with groin pain or injuries.