Why do we care about internal rotation at the hip (specifically the FA joint) ?
Being able to internally rotate at the hip joint is a necessary action for non-compensatory gait. In other words it’s a movement we need when we walk. Which means we need it to run, when we play sports, or when we train in the gym.
Gait requires the movement of our centre of mass over and around the stance limb, to allow the swing phase from the non stance limb. This movement should occur primarily at the FA joint of the hip (the ball and socket joint). In other words the pelvis must be able to rotate OVER the femur of the stance leg. Being able to observe an acetabular rotating over a femoral head during normal gait is challenging at best – hence the need for passive table based assessments (the goal of which is to understand truly what that individual body can do when someone else is in charge).
If for whatever reason adequate internal rotation is not available at this joint then we, as the master compensators that we are, will ‘borrow’ motion from the next available segment – usually one segment above or below (so in this case the knee or the lumbar spine).
Hip internal rotation is affected by a number of factors, but principally by alignment and the maintenance of a ‘canister’ position between the pelvis and the ribcage. A canister position not only safeguards the lumbar segment, but also orients the two hip sockets in the same direction – meaning that as long as we don’t have any other mechanical restrictions (bone spurs, screws, pins, labral issues etc), then we should see reciprocal movement from both joints.
Learning to assess internal rotation at the hip joint gives a far greater understanding of what a client or athlete will experience when you come to challenge them with exercise or movement. The incredibly smart people at the Postural Restoration Institute have a myriad of resources for non manual techniques to restore the orientation of the pelvis, and therefore improve reciprocal moves of the hips during gait. You can check out their educational resources here
Paying attention to the details can make all the difference when looking to improve performance, marginal gains do add up in both general population as well as elite athletes. The expression small hinges swing big doors was coined for a reason!
Principles of assessment is one of the topics covered in mine and Tony Gentilcores Strategic Strength workshop, click here to sign up for the next event in London in September