Strength and Power Testing In Knoxville
The Three Layers of Every Test We Run
A score on its own tells you almost nothing. Here is what we actually read, and what each layer changes about your plan.
Put someone on a force plate and you get a number. Jump height, peak force, a percentage difference between sides. That number does not tell you much on its own.
Fig. 01
Two athletes can post an identical score and need completely different programs. The score does not separate them.
What separates them is what we read around the number. There are three layers, and we look at them in a specific order.
Layer 01
The strategy
This is the first thing we see, before any data loads.
How willing are you to load that leg? How quickly are you moving? Are you committing to the movement, or is something in you holding back a little at the bottom?
You can watch someone step onto the plates and tell a great deal from the first repetition. There is a difference between a leg that gets driven into the ground and a leg that gets lowered onto it. That difference shows up as trust, and it is not always something the person is aware of.
Then we ask the same questions of the other side. How does this compare left to right?
That comparison is often where the conversation starts. Someone will tell us their knee feels completely fine, and then load it noticeably more gently than the other one. They are not being dishonest. They genuinely do not feel it. Their nervous system has quietly decided to protect that joint.
Fig. 02
Here is what that looks like on the plates. This is one countermovement jump, both legs recorded at the same instant, one line per side.
Both legs unload evenly. That first dip looks about the same on each side, which is why this athlete passes the eye test.
What happens next is the problem. Through the whole lowering movement and on into propulsion, the left leg produces much less force than the right. The shaded gap is force that side never contributed. That is a willingness to load problem as much as a strength problem, and the two need different treatment.
Then look at the landing. The gap is wider still. The left side accepts far less force on the way back down, which is the same protective pattern showing up at the moment the joint is under most stress.
Nobody watching this athlete jump would have seen either of those things.
Layer 02
The result
This is the layer most people think of as the test.
Force and time. That is what the plates actually record, a thousand times a second, and from those two things comes a long list of metrics we can pull.
Fig. 03
Off that one shape we get peak force, peak landing force, jump height, and the symmetry between your two sides.
Then there are the questions underneath those numbers. How quickly can you decelerate? Slowing your bodyweight down is what protects a joint on landing, and it is frequently the thing that comes back last.
How quickly can you produce force, not just how much? A knee gets injured in the first fraction of a second after your foot hits the ground. Maximum strength alone does not act that quickly.
How springy are you off the ground when contact time is short, which is what running and cutting actually ask for?
There are dozens more, and part of the skill is knowing which ones matter for you. A distance runner and a soccer player with the same knee do not need the same metrics watched.
One leg at a time
A double leg jump shows us your strategy. A single leg jump shows us your true capacity on that limb.
Fig. 04
The difference shows up before the athlete leaves the ground. The uninvolved leg drops fast and gets deep. The involved leg barely dips, and that is an unwillingness to drop quickly rather than an inability to jump.
Watch what it costs. The lower peak force on that side means less work is being done during the lowering movement, which sets up a poor push off. Everything after that point is smaller.
That first dip is the problem. The lower jump height is only the consequence.
A number on its own gives us very little insight. Read alongside the force time curve and a detailed physical assessment, it tells us what to work on and how to get you back to doing what you love.
Layer 03
The context
This is the one that turns data into a plan. Why are you moving this way?
Is something restricted? A stiff ankle or an irritable joint will change how you load every time, and no amount of strength work fixes a range of motion problem.
Is something weak? Sometimes the answer really is that the tissue cannot yet do what you are asking. That is a straightforward problem with a straightforward solution, and it is often the quad.
Is there hesitancy left over from an old injury? This one gets missed constantly. Someone who tore an ACL two years ago, or rolled an ankle badly in high school, may still be protecting that side long after the tissue healed. The strength numbers can look fine and the movement still looks careful. That is a confidence problem, and it needs coaching and graded exposure rather than heavier weights.
Get this layer wrong and you can spend eight weeks loading a leg that did not need loading, while the actual restriction sits there untouched.
Why all three, together
Any one layer on its own will mislead you.
Strategy without numbers is just an opinion about how someone looks. Numbers without strategy tell you what happened but not how, so you end up chasing a score instead of the thing producing it. And both of those without context leave you with a very well documented problem and no idea what to do about it.
Put them together, with a clinician who has seen the pattern before, and you get something useful. You get to see exactly what is going on and build a plan that goes after it directly rather than hoping general rehab covers it.
Then we measure again
This is the part we care about most.
Testing once gives you a starting point. Testing repeatedly tells you whether what we are doing, and what you are doing between visits, is actually working.
Every four to six weeks we test again. If the numbers moved, we know the program is working and we progress you. If they did not, we would rather find that out at week six than at week sixteen, and we change the plan.
That is the whole point. Not to collect data for its own sake, but to make sure nobody is guessing about your recovery, including us.
Frequently asked questions
Do I need to be injured to get tested?
No. Plenty of people come in for a baseline before a season or a training block, and knowing your numbers while healthy makes any future injury far easier to manage.
How long does a test take?
The individual tests only take a few minutes each, so if we are retesting you it is very quick. Your first evaluation session is usually about forty minutes. If we are running a full return to sport or longevity testing battery, plan on eighty.
Will you explain the results to me?
Yes, in plain language, with the actual charts in front of you.
Does it hurt?
No. The tests are maximal effort so they are demanding, but we choose the right tests for where you are in your recovery.
What if my numbers are bad?
Then we have found the target. A number you do not like is far more useful than a vague sense that something is off.
Do I need a referral?
In Tennessee, generally no. You can come straight to us.
Get tested
Our passion is using this technology to guide you back to what you love doing.
If you are working back from an ACL injury, a stubborn knee, or you just want to know where you stand before a season, we can test you and show you exactly what we find.