How Much is Enough?
How much range of motion does your joint need?
While I was treating their knee, a client asked me, “How much range of motion is enough”? This question is often asked and has a different answer on a case-by-case basis because individuals each have different needs.
This particular client is a snowboarder, so I rhetorically asked him what the needs of snowboarding entail. Having spent time in snowboard and other binding types, I had a rough gauge of the rotational capacities needed for the knee. Obviously, the knees need to be able to flex and extend, but a person’s bindings are set up in a way that is particular to the rider, creating different constraints on the knees.
My client has his bindings 24” apart each at a 15-degree angle, keeping them symmetrical so he can switch stances from regular stance (left foot forward) to goofy (right foot forward) while riding.
This binding setup gives us a glimpse as to how much external rotation is needed, no less than 15 degrees. But this doesn’t account for the dynamics of his snowboarding style, so we need added degrees in external rotation as a buffer to, say, 20 or more degrees.
Side note: I recognize that the hips play a role in all of this as well, but to keep things simple, I am focusing on the knees.
Based on his assessment, we noticed we needed to put in more work on the internal rotation of the knee. Because of the 15-degree angle on the bindings, thus putting him in an externally rotated position, we also had to consider the amount of internal rotation created from the femur having to move relative to the otherwise fixed tibia or shin bone while flexing. This is what landing off of a jump would entail, minus the impact, which we can discuss later.
Given the amount of internal rotation we have already achieved via treatment, combined with the foot and shin position due to the bindings, it still wasn’t enough for the demands of snowboarding.
Fortunately, I could assess my client’s knees while in his bindings, which allowed me to watch his joints like any other assessment. Only this time, I had to assess fewer degrees of freedom. With his feet secured in his bindings at 15 degrees, I had him squat as he would when riding and landing off of a jump. Immediately as his hips descended, we could see our hard work paying off. I watched the femurs move around the shin bones nicely. But then we hit the outer limits of his joint rotation, and instead of continuing to squat (which requires more knee internal rotation), he began to hinge and reach his hips back to compensate.
He could feel the pull on his medial knee as he approached and hovered in his squat-hinge position. We had our answer: we needed enough internal rotation of the knee to allow his hips to drop close to his heels–however many degrees that ended up being, plus a little more as a buffer. Further, we also have to ensure that his connective tissue has specific capacities and buffers to withstand the demands of snowboarding. In other words, can the connective tissues of his knee joint absorb a landing off of a jump at a full squat and internal rotation?
Our goal is to create as much joint workspace in the knee joint via rotational inputs to give him the freedom to squat and transfer weights in awkward positions like the ones in snowboarding. We must train to achieve reactive strength of the connective tissue and also to support the demands of this sport.
We will achieve this goal by having a strategy working from our initial starting point toward the desired joint workspace. Our strategy will include manual therapy, joint-specific training from ACCES, and external-based strength training using sled work, over-speed eccentrics, and others in a particular programming sequence to elicit the desired effects.
A training week may look like this:
Day 1: Manual therapy to improve joint workspace and connective tissue load-bearing capacity.
Day 2:
Sled work–high volume, lower load
Curtsey squat–eccentrics–3x5
Over-speed Eccentrics 5x5
Day 3:
Rest, manual therapy, or joint-specific training
Day 4:
Repeat day 2
Enough is Enough
This is just a snapshot of one example of an individual who also falls into another niche, e.g., a snowboarder, showing how his “enough” would be different than your enough, or a baseball player’s enough. Enough depends on a person’s needs, depending on their environmental demands.