CRICKET BOWLING & BACK INJURIES Summary Presentation

1. CRICKET BOWLING & BACK INJURIESSummary Presentation The 2013-14 Ashes series is underway but the build-up has been slightly overshadowed by the injuries to 5 of the fast bowlers (Right) who played in the summer’s Ashes series. Each of the five bowlers suffered from a variation of lower back injuries, namely stress fractures. The risk of the lower back injuries is one that all fast bowlers have to deal with due to the nature of the cricket bowling technique as outlined in the following presentation.

2. The Bowling Action • Run-Up • A accelerating approach to the crease • Exposes body to normal running GRFs • Finishes with a bound into the crease where body alignment is set • Delivery Stride • Back foot and front foot contact moments to set pelvis in position • Exposes body to excessive GRFs (6-8x Body Weight) • Trunk rotation follows to bring bowling arm through to release point • Excessive stress and strain placed on spinal column • Follow Through • Continued rotation of the upper body bringing bowling arm across to far hip • Couple of steps following push off out of bowling stride • Gradual return to standing position Full unedited video:

3. Back- and Front-Foot Contact (BFC and FFC, respectively) • At FFC, body is exposed to • 6-8x Bowler’s body weight • Causes spinal column • compression • ↘ Excessively loading the • intervertebral discs • Creates the base from • which the bowler • bowls • Locks pelvis in position • for trunk to rotate • around • Extended front leg significantly correlated with bowling speed • ↘ Suggested flexion- • extension motion to • avoid injuries and • allow high bowling • speeds • Extended FFC lead knee • significantly correlated • with back injuries • Use of extended knee (or • hip) reduces shock- • absorbing capacity

4. The Delivery Stride While absorbing the high GRFs, the trunk makes a variety of motions in a short period of time • Predisposes the bowler’s trunk to injury

5. Hyperextension & Flexion • ROLE • Allows bowling arm to fully rotate around the shoulder • joint and across the body • Allows bowler to look inside their non-bowling arm • Aids in targeting ball trajectory • DANGERS • Can cause damage to intervertebral discs when excessively • loaded • ↘ Hyperextension places loads on rear of disc • Can cause spinous processes of spinal column to collide • Continued extension-flexion motion of further predisposes • bowler to back injury

6. Lateral Flexion • ROLE • Raises bowling shoulder creating high release point • Allows full rotation of bowling arm without full shoulder ROM • Eases arm’s follow-through across the body to opposite hip • DANGERS • Excessive flexion can loose ball release height • Puts excessive strain on side muscles • ↘ Can cause different loading patterns on each side • Moves the spine from neutral alignment • ↘ Creates excessive on the articular processes • Excessive repetition can cause spondylolyis and/or • intervertebral disc strains in the lateral aspects of the disc

7. Axial Rotation (& Counter-Rotation) • ROLE • Brings bowling shoulder and thus bowling arm forward • towards target • Utilises trunk rotator muscles in producing ball release • speed • Aids in propelling the body through remainder of action • Excessive counter-rotation is significantly correlated with decreased bowling accuracy • ↘ Decreases head and trunk stability • ↘ Loss of visual link on target • DANGERS • Excessive counter-rotation significantly correlated with • increased injury risk to lower back • Creates high levels of torsion on spinal column and trunk • musculature • Increases compressive loading on facet joints when • combined with trunk forward and lateral flexion as well as • hyperextension • Trunk muscle co-activation patterns increase stress and • strains on spinous processes Axial rotation around the spine

8. Common Back Injuries • Spondylolysis • Vertebral defect in the pars interarticularis (vertebral arch) • Can result in back and neck pain, stress fractures, spinal stenosis, • caudaequina syndrome, radiculopathy, cervical myelopathy, and • spondylolisthesis • Scoliosis • Curvature of the spine • Can produce distortion in the epiphyseal cartilage that deform the • vertebrae or intervertebral discs which leads to a variety of further • injuries • Disc Degeneration • A wearing away of the intervertebral disc • Decreases shock-absorbing properties of spinal column • Can cause vertebrae to collide and/or grind against one • another and lead to further damage to the vertebrae