Gait Video Case of the day: The Frontal Plane Hinging Knee.
This is both a simple case, and difficult one. Simple because the diagnosis is easy. Difficult because there is not much you can do for it. But you still have to recognize it.
This person came to see us with a chief complaint of left hip and knee pain and right medial foot pain. It should be simple to see that the left knee is degenerative particularly in the medial compartment of the knee. You can see with the person walking that when the left leg is loaded there is a frontal (sideways) shift of the knee to the outside. This gives the appearance of a bowed (genu varum) knee. What you need to see and understand is that when they load the limb the knee moves laterally to the outside and this is going to challenge the left hip, particularly the gluteus medius, but it it is also going to press the lateral trochanter bony prominence of the hip into the bursae and soft tissue structures like the IT band. Both of these soft tissue structures can become quite inflamed and painful. Fatigue failure of the left gluteus medius in this kind of case will lead to pelvic obliquity and abdominal asymmetry and difficulties with symmetrical core stabilization of the spine. Low back pain is not uncommon in these types of cases.
So why the RIGHT foot-ankle pain ? Well, when the left knee moves laterally the hip and pelvis move laterally very suddenly rendering a kind of functional short leg on the left but it will also, as you can see in this case, an abrupt lurch onto the right limb. This sudden lurch onto the right is because the brain knows that the left limb is unstable and challenging an improper plane for the knee (it is only supposed to hinge forward and backward) and so the weight bearing phase on the left is abbreviated. And so, when you abbreviate the stance on the left the right side is loaded sooner, longer and faster. In this person’ case, the loading as such has been going on for so long that the pronation phase has become excessive enough to pound down the right arch and challenge the right tibialis posterior muscle. Remember that the tib. posterior is designed to invert the rear foot (look carefully in the video, the client has lost this ability and the rearfoot is constantly everted) and it also helps to stabilize the longitudinal arch of the medial foot. In this case, the client has undergone such excessive loads into pronation that she is now hyperpronating. The tibaialis posterior has developed longitudinal intersubstance tears which now need surgery quite possibly.
This is a left knee that needs replacing asap to not only reduce the left knee issues, but to dampen the challenges into the left hip (so surgery there is avoided) and so that the timely stance phases on each foot can be restored and ease the burden on the right tibialis posterior and arch stabilizers.
Intervention ? perhaps temporarily, reduce the lateral shift and functional drop on the left with a full sole length lift. We start with 2mm of rubber infused cork and see them again in two weeks to see if more is needed. This will reduce all of the gait aberrations noted above, but it does not fix the problem. You are managing the issues for the client, buying them time. Adding an orthotic on the right foot can be done, to slow the pronation, but if the height of the orthotic is too much they will pronate into it and cause plantar pain from meeting the orthotic with force.
This is a pretty classic degenerative knee gait. We see this one in our offices several times monthly. Look for it ! We get some wild and worn body parts coming into our offices. Everyone walks so everyone gets a gait evaluation and an examination to prove or disprove the deviant gait appearance as part of the present clinical picture. Once you get good at the stuff and train your eye after many years, like us you might not need a treadmill or slo-mo camera.
Shawn and Ivo, the gait guys.