DIAGNOSIS AND REHABILITATION

of the trunk. McGill et al (18) have high- lighted the important role of the quadra- tus lumborum in stabilizing the lumbar spine. As Weatherley (13) showed, 80% of unilateral spondylolyses occur on the opposite side to the bowling arm. This would suggest that repetitive forces through the opposite side of the lower back to the bowling arm may be aggravat- ed by a lack of stability due to an asym- metry in the quadratus lumborum and this could increase the risk of pars interarticu- laris fractures.

3) Psychological factors A study by Marras (19) showed that there is a biomechanical pathway to spine load- ing associated with psychological stress. It suggests that the pathway is complex but that spine loading is increased through alterations in muscle co-activity and trunk kinematics. The study does sug- gest however that this would be more apparent during low physical activities and that during high physical activities the biomechanical demands would out- weigh the effects of stress. The results of the study represent short-term responses to stress and it may be possible that long- term exposure, as would occur during fast bowling, may increase co-activation resulting in more permanent changes in the neuromuscular system.

This same study suggests that personality traits may be responsible for spine loading

KEY POINTS

■ Lumbar spondylolysis (or a defect of the pars interarticularis) is common in sports that involve combinations of lumbar rotation and lateral flexion under pressure

■ Young sportsmen and women are more susceptible to this form of injury ■ Young fast bowlers in cricket seem to be more prone than most ■ The cause may be multifactorial and could include biomechanical, physiologi- cal and psychological elements

■ The biomechanics of the bowling action has been the subject of much research, but despite this and the resulting changes in the bowling action that have been encouraged, the incidence of spondylolysis remains as high as ever.

■ Research has divided the bowling action into basically three different actions. The ‘mixed action’ is thought to be the one that puts the bowler at most risk of developing a spondylolysis in the lower back.

■ Treatment for this type of injury has traditionally involved just rest, but should involve a far more ‘functional rehabilitation’ approach

■ Functional rehabilitation should include taking the player back down to basics and building them up one step at a time, including such elements as pelvic stability, core stability and strength, flexibility, muscle imbalances and abili- ty to absorb shock through the various systems more effectively.

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differences. Introverts showed increases in compression and lateral sheer forces, which may be due to their internalising thoughts and feelings, which could result in increased co-activation and higher spinal loading. Although these studies were not performed on cricketers or even fast bowlers, it is of interest and demands more research if we are to identify all the possible causes of overuse injuries.

The fast bowler is often seen as the key member of the team, the one who is meant to ‘make things happen’ if the game is not going well. He will open the bowling attack in an attempt to dismiss the best opposition batsmen early on in the game. This responsibility can weigh heavily on young fast bowlers who do not yet have the maturity to deal with the demands placed on them by captain and coach.

These stresses could be compounded by the state of the game; bowling figures that do not read well; the need to take wickets in order to remain in the team and being asked by the captain to continue bowling when feeling fatigued.

SYMPTOMS Symptoms can vary greatly between play- ers. It is common to have some form of pain in the lower back which is gradual in onset and non-specific in nature. It some- times presents as a dull ache especially

after activity and a sharp pain during spe- cific activities such as the bowling action. Bowlers are often able to continue bowl- ing at 60-80% but are just unable to put in the extra effort to bowl at 100% with- out pain. They are often able to run around quite easily, but as soon as it is necessary to sprint around the boundary edge, as this is where most fast bowlers are asked to field, they pull up because of pain or just an inability to sprint. The area of pain tends to radiate from the lower back out towards the crest of the ilium. Although there may be some refer- ral of pain towards the gluteal area, this would probably be due to the involvement of other structures.

Findings on assessment ■ When assessing the player objectively, it is common to find pain on lower back extension as well as the quadrant position. Extension in the stork position (single leg standing) can also produce pain.

■ On palpation it is common to find that the quadratus lumborum on both sides and the multifidi at the affected level are tight with trigger points present.

■ Mobilisation of the affected level often reproduces pain and a sense of the joint bouncing back at you as it refus- es to be moved with ease.

The diagnosis of a lumbar stress fracture is not always an easy one to make and it is often a case of eliminating all the other possible causes before settling on a spondylolysis.

TREATMENT If one adheres to the premise that it is an overuse injury, then practitioners need to appreciate the multifactorial aspect of the aetiology of overuse injuries.

Although as a therapist we can do little to affect a player’s bowling technique or even the number of overs they are asked to bowl by coach and captain, it remains important to be aware of them and make the player aware of them. A good rela- tionship with the coach could offer an opportunity to discuss these issues but be warned against telling a coach how to do their job.

Once the diagnosis has been confirmed the player would have to be rested from bowling and it is not unheard of for a

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