Continuing with a theme from the previous article where I talked about movement and tissue quality, I wanted to hit on another topic that follows in the same vein. Cleaning up all types of movement is something that should come first and foremost on our list of priorities as strength & conditioning coaches. Of course, technique in the weight room is of paramount importance (although I’m still not entirely convinced we all have a great grip on the finer points of technique) in order to prevent injuries during training. Additionally, training technique is important because without proper technique we have no idea if the exercise we’ve chosen is even targeting what we want it to. Something as simple as a back squat turns into a low back and quad exercise/annihilator when performed in posterior pelvic tilt. If that doesn’t make sense to you, neither will the rest of this article.
For now though, what about movements more specifically related to the ones that occur in sport? Unless you have specific knowledge or credibility in certain areas it is unlikely that your input on the release of a jump-shot, or striking a corner kick will be welcome by a sport coach. What we should be aiming for is helping the athlete move safely, efficiently and resiliently.
In this article I want to hit two topics.
- Change of direction: Center of mass & Base of support.
- Single leg knee mechanics: Degree of excursion & Time to stabilization.
First: Change of Direction
In athletic movement, change of direction ability is something that weeds out the competent from the vividly average. An athlete who quickly and efficiently changes direction creates opportunities for themselves and their team. Watching some simple change of direction drills we can look at the relationship of two criteria to appraise the efficiency of the movement.
Below is a short video of two simple drills involving lateral change of direction using shuffles and crossover steps.
With respect to lateral cutting, I believe there are primarily two factors (postural correctness is the other) that dictate the quality and efficiency of movement. The relationship between the center of mass and base of support is what I’ll cover today.
So by now, you know I like to draw on my pictures. Anyways, these are taken from the video. The top image is a comparison of two separate reps on the shuffle drill with a cut. Fortunately I was able to line up the acoustical padding as a reference point in the picture. In the left picture the athlete was cued to execute the drill with 50% speed. In the right picture, she was cued to execute at 75% speed. Comparitively, as the speed of the movement increases, the demands change. The center of mass needs to drop, and the base of support needs to become wider. The shape of the triangle (as best and biased as I could) illustrates the degree to which it changes as the speed of movement increases. The line of force will follow directly from Point A (Center of mass) and Point B (Cutting foot contact.) If the athlete were moving at 75% speed in the first picture, the result would be different. The Center of mass would be too high for the base of support and momentum would have caused her to fall onto the outside edge of the cutting foot, or have to stutter-step in order to adjust the base of support.
This second picture is three reps (50%, 75% and 100% speed of execution.) Again, the objective was to illustrate the relationship between Point A (Center of Mass) and Point B (Cutting foot contact.) As the speed of movement increases, the angle of the line drawn from BOS (base of support) and COM (center of mass) must decrease in relationship to the floor in order to execute the cut correctly.
So in the spirit of “keeping it simple” these drills can be a very effective illustration for your athletes. Using them in a warmup for agility training sessions or before a game can help call their attention to the two most fundamental components of directional change. at 50% get low and get wide, at 75% get lower and wider, at 100% get lowest and widest.
Second: Single Leg Knee Mechanics
Moving on, in an effort to simplify a complicated topic. Here are some basic things I use to address injury protection specifically related to knee mechanics and what I look for during drills. In the case of single leg movements there are really three MAJOR components to sound movement strategies
- Postural Correctness
- Degree of Joint Excursion from “Ideal”
- Time to Stabilization (Return of Joint Position to “Ideal”
First: Postural Correctness
First and foremost comes postural correctness. Moving into a more specific movement challenge like single leg landings, it’s paramount that we detail the importance of postural correctness to our athletes. In this case specifically, I am referring to pelvic tilt and orientation of center of mass.
In landing mechanics coaches commonly cue things like “land soft,” “hips back,” or “chest over toes,” but does what we say line up with what we need? It’s possible to accomplish pushing the hips back and having the chest over the toes without actually providing any additional protection to the joints of the lower extremity.
- Hips back – You can push your hips back in posterior tilt and feed slack to your hamstrings. You can also choose to limit the duration of your athletic career. Slack hamstrings in landing mechanics equates directly to increased reliance on eccentric quad activity to absorb force and slow the flexion of the knee. With disengaged hamstrings, you create a forward shear of the knee which increases reliance on the patellar tendon and passive structures. These are mechanically suited for the job, but acting alone can (probably will) lead to tendonitis, and sprain/tear of ligaments.
- Chest over toes – You can easily get your chest over your toes in posterior pelvic tilt and lumbar flexion. Just because the landing is “soft” doesn’t mean it’s mechanically efficient. With a decompressed abdomen and spinal flexion, it’s true: you are displacing the ground reaction forces over more segments and dampening the impact. But you are also NOT TRAINING proper landing mechanics.
Here is a video of some simple drills. WARNING: The first rep SUCKS.
In order, the drills are:
- Hop & Stop
- Triple Hop & Stop
- 10 & 2’s
- 10 & 2’s – Stop Every 3rd Contact.
- Single leg Jumps
Aside from displaying my cinematic finesse, I’ve slowed down the landing portions of the movements in some cases so we can see them slowly.
Second & Third: Degree of Joint Excursion from Ideal and Time to Stabilization.
I attempted to draw both real and imagined possibilities over two images above. The green lines are ideal or close to it (although the second one might be a bit laterally exaggerated.) The red are lines detailing the DEGREE OF EXCURSION from the ideal position.
The degree of excursion is what we see when we recognize “wobbliness” or “buckling” of the knees. Doesn’t really matter what we call it. The degree of excursion (in the frontal plane in this case,) is a primary indicator for a couple of insufficient qualities.
Time to stabilization (by my definition) is how long it takes for the athlete to make the correction of joint position from pathological to ideal. From the time they initiate contact with the ground until the knee stops wobbling or buckling, is what I term the time to stabilization. A slower time to stabilization also indicates insufficient development of a couple of qualities.
In a very general sense, the following are what I believe to be some of the contributing factors to pathological landing mechanics and strategies.
- Poor Motor Control
- Poor Neuromuscular Coordination
- Postural Incorrectness
Although I believe some contribute more to the degree of excursion (Postural Incorrectness and Weakness) and some more to the time to stabilization (Motor Control and Neuromuscular Coordination.) They are all problematic by themselves in either case.
It is important that we recognize increasing strength isn’t always the only answer. Although there are some insanely strong people that despite horrendous athleticism and motor control have the ability to resist injuries, they do so IN SPITE of their training, not because of their training.
When progressing jumping and landing exercises, there is a simple progression I use, and simple criteria for advancing to each progression.
Following these simple guidelines you can progress your training drills in this regard based on choosing drills that follow the continuum. Advancing from one segment to the next will be dictated by your appraisal of the degree of excursion and time to stabilization.