DIAGNOSIS

action of the hip joint muscles. Muscle imbalances around the pelvis have been suggested as a factor in the aetiology of adduc- tor related pain (22). If not corrected during rehabilitation these imbalances may not only be the cause of the adductor strain but also prevent full rehabilitation.

Similarly it has been demonstrated that a loss in core stability may eccentrically overload the adductor muscles. Following acute strain this increased eccentric load may be sufficient to prevent a relatively minor strain from healing and allow the injury to go on to become chronic. The athlete may have had some time off sport resting following an acute adductor strain but the importance of continuing some modified core stability work, as pain allows, is tremendous.

5. Neural component in adductor muscle strain The possibility of neural component pain should be considered when an athlete presents with symptoms which continue for longer than the expected healing time.

It is now well accepted in the literature that sporting injuries such as hamstring strains and ankle injuries may have a neuro- genic component. Hamstring strains may have an element of sci- atic involvement and ankle sprains may involve the peroneal or tibial nerves (24, 25). The presence of altered neurodynamics in the groin has implications in the management of an athlete with groin pain.

It has been demonstrated that Grade 1 hamstring strains that tested positively to slump test (neurodynamic test) responded more favorably to treatment which addressed this neural compo- nent (24). Identifying and addressing altered neurodynamics in the groin region may be an important factor in the rehabilitation of acute adductor injuries.

Altered neurodynamics may elevate the resting tone of muscles. Increased tone predisposes muscles to intrinsic muscular pathol- ogy. This theory helps explain why some hamstring injuries recur and become chronic.

Traditional treatment methods may not have adequately addressed neural structures. Neural tests are now widely accepted in the assessment and treatment of hamstring muscle injury and the slump test can be used to assist in differential diagnosis and there- fore ensures the most effective treatment regime is implemented.

In the case of groin injury the same theory may explain why groin muscle injury recurs and becomes chronic. It is essential to test for neural mobility and implement the appropriate treatment if a component is found to exist.

Mechanisms which may result in altered mobility of the obturator nerve and neural pain: ■ Local inflammation may contribute to increased neural sensi- tivity. Athletes often suffer from conditions such as osteitis pubis for prolonged periods of time. The ongoing inflammatory process may increase nerve sensitivity (intraneural) and may explain some of the athlete’s pain and discomfort.

■ The athlete struggling with chronic groin pain may have suf- fered recurrent injuries resulting in scar tissue formation with-

www.sportex.net ALTERED NEURODYNAMICS – WHAT IS IT?

The concept of abnormal neural tension (ANT) was developed by Butler 1991 (26). More recent literature describes ANT as altered neurodynamics (27).

Altered neurodynamics describes the inability of the nervous system to move concurrently with changes in body position. The spinal cord and peripheral nerves are a mobile elastic structure which is designed to move and adapt to any changes taking place in body position. However physiological and mechanical dysfunction can occur which affects the nervous system resulting in pain and decreased range of movement (28).

The nerve may be affected by extraneural or intraneural fac- tors. Extraneural dysfunction describes an alteration in the mobility of a nerve within the tissue it runs through. This is known as an interface problem.

Intraneural pathology describes abnormalities within the nerve itself such as an increase in nerve sensitivity (27).

Normal nerve function is dependent on the maintenance of correct nutrient pressure gradient. Compression of the nerve greater than 30mmHg or tension greater than 7% elongation is sufficient to cause neural venous congestion (28).

Relatively minor trauma or subtle alterations in biomechanics around the pelvis can therefore produce changes in pressure gradients sufficient to result in neural pathodynamics.

Neurodynamic tests for different peripheral nerves may be deduced from their position relative to joint axis and the direction the joint is moved to exert a tension on the nerve. Neurodynamic tests involve a systematic increase of the ten- sion on nerves by successive additions of joint movements. The test may provoke the symptoms that the patient complains of or other symptoms such as pins and needles. The amount of resistance encountered during the test may be affected by each component of the test and the amount of resistance is particularly significant when comparing the uninjured side.

in the muscle. Scar tissue may interfere with the normal mobil- ity of a nerve as it passes through the muscles. Repetitive trauma in chronic adductor strain produces haemorrhage and chronic inflammation which can lead to either extraneural or intraneural pathology.

■ The obturator nerve may be compromised by changes in the fascia of the pelvis. These regional sheets of fascia can be dis- torted by factors such as trauma, poor posture or inflammation. It is therefore essential to ask the patient about previous surgery such as appendicitis, hernia repair or caesarian sec- tions. It is also relevant in the athlete who has had surgical exploration of the groin.

■ Adductor brevis fascia - the obturator nerve is thought to be at risk of entrapment at the level of the obturator canal and prox- imal thigh rather than the obturator tunnel as suggested by the obstetric and general surgical literature. The nerve becomes

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