I’ve been having an ongoing discussion online with regards to testing and improving core function. The discussion was over an isometric test for hip Abduction in supine being a relevant test for core and hip stability for swimming. The problem with this is the theory behind core function and how it is deemed to be applicable to specific sports or actions.
Most of our understanding of core dysfunction comes from the research done in the late 90’s by Hodges, Hides, Richardson et al in Australia. Their research was ground breaking in terms of showing the diminished response of transverse andominis in the presence of pain and dysfunction, therefore resulting in potential further problems in rehabilitation. This model has been developed and progressed by these and many others, however from my perspective there is a problem with what the research found and how it has been interpreted for ‘core’ function.
If we look at the lumbar spine, everyone can agree that we do not want instability, but we also do not want rigidity. Most of the ‘core’ tests involve the core being engaged isometrically (no movement) and then moving the lower of upper limb in one plane of motion whilst in a supine/prone position. If we have an unstable segment this approach will probably stop the excessive motion by making the spine rigid, but how much carry-over is their to the clients day to day activity and do we want a rigid spine?
If we look at freestyle, the rib cage and pelvis will separate in all 3 planes of motion creating movement in the spine and lengthening and shortening the abdominal muscles simultaneously. This can be seen brilliantly via this youtube video of Michael Phelps
If his core was working isometrically (no movement) would be move so well? Of course not!
Creating a rigid core would not only decrease his swimming efficiency but also decrease his thoracic motion (abdominals attach as high as 3rd rib?) affecting his upper limb mechanics, but also the pelvic motion would be restricted affecting the lower limb. Recipe for disaster!! And poor performance
If we are to look at the core function of a client/athlete we need to assess the demands of their daily lives and create an assessment and rehabilitation process for the individual, whilst always remembering that the core has to move in all 3 dimensions both eccentrically and concentrically and occasionally isometrically.
The other question we need to ask is, why has the Lumbar spine become unstable? This may be due to pathology or restriction else where in the kinetic chain. A sagittal plane restriction in the hip flexor would immediately demand more of the lumbar spine into extension when walking, but may be increased when looking at swimming. The same may be true of an extension restriction in the thoracic spine, and this is only a one dimensional approach.
At momentum physio we use a 3 dimensional approach to assessment, treatment and rehabilitation of lumbar instability. Finding the cause of the instability is the key and not just focusing on the symptoms.
Isometric abdominal holds = rigidty = dysfunction.