SPORTS SPECIFIC TRAINING

STABILITY TRAINING FOR THE PREVENTION OF

CANAL DISRUPTION By David Wales MCSP MSc

INTRODUCTION Stability training is a central component of many rehabilitation protocols and is particularly prevalent in the treatment and pre- vention of low back pain. There is strong evidence to support this approach for the management of low back pain (1). Clinically the stability concept has been accepted and implemented by thera- pists and trainers and the method is widely employed as an injury prevention strategy within the general training programme across many sports (2).

Elphinston and Hardman (3) have described how stability training in a sports environment increased training compliance, reduced the overall injury rate and improved sporting performance. Although the benefits of implementing a stability training pro- gramme are widely accepted, it is unlikely that all of these improvements are solely due to the implementation of stability training. Other variables such as the ability of the coaching and medical staff and a discontinuation of previous training methods are likely to contribute just as much as the implementation of new training interventions.

Anecdotally, the implementation of stability training has coincid- ed with a decrease in the incidence of inguinal canal disruption within elite level soccer players. Despite there being no objective evidence for a protective mechanism provided by stability train- ing in the pathophysiology of inguinal canal disruption, a theory is proposed whereby the anatomical composition of the inguinal canal is supported via the muscular bracing effect that can be elicited with stabilisation exercises.

THE INGUINAL CANAL AND INGUINAL CANAL DISRUPTION Teague (4) describes the role of the transversalis fascia and the conjoined tendon of the internal oblique and transversus abdomi-

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nus muscles in the formation of the posterior wall or 'floor' of the inguinal canal; as well as the role of the external oblique aponeu- rosis in the formation of the anterior wall (see figure 1).

The transversalis fascia, oblique muscle layers and conjoined ten- don can become stretched as a result of the extreme demands of soccer, notably during extreme ranges of hip abduction and hip extension. This stretch weakness can precede inguinal canal dis- ruption once these tissues are subject to increased intra-abdomi- nal pressure. Gradually, microtrauma and fascial sprains can lead to tissue damage and inguinal canal disruption.

The proposed protective mechanism of stabilisation training is the co-activation of these muscles in order to increase the stiff- ness of the inguinal canal. Increased stiffness is thought to help the inguinal canal withstand the tensile forces which are respon- sible for causing stretch damage.

STABILITY TRAINING The training of spinal segmental stabilisation and movement con- trol has been described well by Richardson (1). Direct and indi- rect evidence supports the use of isolated stabilisation training in the treatment and prevention of low back pain (5,6) and other sporting injuries (3).

Bergmark (7) asserted that two distinct muscle systems were responsible for lumbo-pelvic stability. The systems were defined as: 1) The global muscle system 2) The local muscle system

The global muscles tend to be superficial; are not generally attached directly to the spine; and are large torque producers eg. rectus abdominus. These muscles can't directly influence stability at a seg- mental level. Comerford and Mottram (8) more recently sub cate- gorised the global system muscles as global mobilisers or global stabilisers, based upon their action. In contrast, the local system

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