This week's post is a primer on an excellent, quick way to view an athlete's ability to maintain motor control during a movement needed for virtually everyone (athlete or not). The ability to simultaneously stabilize on one leg while dynamically moving and controlling the other gives insight into whether an athlete is a coordinated gazelle or a broken mess. Check out the video and ideas below. Observing this simple movement (let's call it Standing Knee to Chest) can go a long way in screening and helping to diagnose movement faults:
Why is this movement important? Effective single leg stability and mobility is essential for those in nearly any sport. Sprinting, jumping, throwing, even going up the stairs all require movement of one leg with simultaneous stability in the other leg. If you don't create active stability and control in the system, your body will compensate to find it potentially resulting in overextension of the spine, pelvic drop, decreased range of motion, potentially leading to injury. Don't believe it? Read this new systematic review. These compensations create an inefficient motor pattern and waste energy which will decrease performance. While this motion is accounted for/in other excellent screening and assessment systems (FMS, SFMA), they don't require maximum knee to chest motion which is necessary in sport and also further elucidates movement and mobility faults.
As stated in the video we are really looking for 3 things during the Standing Knee to Chest (try it, can be an eye-opener):
1) Midline Control: First observe how the athlete controls the pelvis/lumbar spine. These regions are coupled meaning that pelvic position dictates lumbar position. An athlete that overextends at the lumbar spine (due to anterior pelvic tilting) is demonstrating inadequate abdominal motor control. This indicates that the athlete does not understand how to effectively brace the spine, allowing the hip flexors to powerfully tilt the pelvis forward and pull the lumbar spine into extension. The result is a decrease in hip flexion range as the femur prematurely runs into the hip. Try it yourself: first try the Standing Knee to Chest with appropriate midline control, then try it once with your back arched. You will notice less hip flexion and maybe even some pinching indicating that you're essentially self-impinging which is not great if you enjoy having a hip labrum. I'm not suggesting that the spine is mechanically unstable (the vertebrae probably won't buckle and collapse) but rather the lack of appropriate midline control is a detriment to optimal movement patterns.
The fix: Organize your spine! Squeeze the glutes and brace the abdominals prior to lifting. Clear up a disorganized midline and range of motion and stance leg stability will often fall into place. Some of Gray Cook & company's anti-rotation exercises are great here to stabilize in the diagonal planes - don't forget about spinal rotation.
2) Active Range of Motion: Active range is what we care about in athletics. The ability to control this range is even more important. Don't forget to look at the quality of the motion. Is the hip flexion smooth and coordinated? Does the leg externally rotate excessively (indicating a possible mobility impairment in an effort to get the hip up)? If you're able to passively take the leg further than the athlete can actively take it, that indicates a motor control problem.
The fix: Dig deeper. Start with organizing the spine - what may appear weak or stiff may just be a lack of proximal stability. Then figure out if the athlete's control is ugly or if they need some hip internal rotation/flexion mobility.
3) Stance Leg Stability: An inability to effectively stabilize on the stance leg is unbelievably common even in high level athletes. It's amazing how much poor stability people get away with before it catches up. Look at the pelvis: do they compensate for poor pelvic/glute control by excessively leaning the trunk? does it drop towards the stance leg (which loads the medial knee compartment and changes the pull of the quadriceps on the knee)? What about the foot? Clawing or splayed toes is something I see all the time in runners lacking stability, excellently described by Chris Johnson, PT. A wobbly foot and ankle is a shaky foundation and if the patient can't stabilize here, there is little hope for stability up the chain.
The fix: Start with an organized midline first. Then take a top-down or bottom-up approach to figure out the limiting factor. You may need to break down the movement into less-demanding components (decrease the hip flexion, for example) to find when and how the athlete is losing stability. Remember, it's often a coordination issue instead of just plain weakness.
Bottomline: the ability to dynamically stabilize and control movement is essential in both everyday life and athletics. If you're an athlete (or coach them) and cannot get your knee to your chest without falling over, it's time to dig deeper into what's driving this faulty movement pattern and the Standing Knee to Chest is a great starting point to make the invisible become visible.