In pursuit of challenging myself to learn more and continue to grow as a coach, I'd like to talk about the use of how Strength is helpful in sport in preventing injury. I've got a lot of holes in my knowledge when it comes to strength training.
By no means should this blog post be taken as Gospel of training. I'm literally thinking through how this stuff works, putting my experience and observations on paper.
How does strength play a factor in creating force and preventing injury? Let's take a look at a recent groin injury to Las Vegas Raiders Quarterback Derek Carr (video below). NFL game speed happens real fast, but at the 26-30 second mark of the video, there is a good vantage point of when he injures his groin. I'll walk through what I saw at the time and what I'm seeing now looking over the video again.
First of all, it's a high stress situation. It's third and goal in the first quarter against the Chargers, a division rival, with playoff implications and Carr's future as a Raider quarterback on the line. Raiders need to take an early lead to help withstand the Chargers' offensive onslaught.
Carr is scrambling to his right as defenders are covering the receiver in the area and another defender right in Carr's face preventing him from just running in to the end zone. Carr is running pretty hard toward the right sideline and he sees a window to either pump fake the ball to distract the defender so he can run it in or he was trying to legitimately to throw the ball to his receiver. Either way, when Carr plants that left foot in the ground, things go wrong.
When he plants the left leg to slow his body down, the stress on the groin muscle is just too much and it gets "pulled", ie, the muscle can't withstand the rate of speed change and it (I honestly don't know which) has micro tears in the muscle, strains the tendon muscle connection, or full on tears the muscle.
As a strength training professional, here's what I see that could lead to the injury -- it is late in the season and his body is fatigued AND/OR there was too much pressure on the groin and it couldn't take the stress. So let's look at WHY his groin possibly couldn't take the stress.
The muscle is weak relative to demand
Pretty straight forward here. But how can you decrease the demand? Agh, glad you asked!
Poor Body Position Increased Demand Unnecessarily
Notice how his body's center of gravity is lower when he is running hard toward the sideline, but then just before the injury occurs, he goes upright and heightens his center of gravity. When he does that, it increases length of the "moment arm" which increases the amount of leverage at the fulcrum point (his hip/groin). So at just the wrong moment, Carr gets more upright AND tries to change his direction/speed and/or plant the leg to throw the ball.
If Carr's center of gravity had been lower, there wouldn't have been as much pressure on that groin. Alternatively, if Carr had tried to plant with his right leg being at that height as well, perhaps he would have rolled his ankle. Same physics apply.
His other muscles weren't ready to help
Tied into poor positioning is that his other muscles weren't able to help absorb the force. If Carr's hip and knee had been a little more bent, loaded position, the surrounding muscles (the quads, glutes, and hamstrings) could have had more stored energy. The stored energy of the muscle would have helped transfer Carr's force (bodyweight x speed) in to the muscles and joints acting like a spring.
Watch this video all the way through.
So, as a strength coach, what is my advice to Derek Carr?
First, add weightlifting exercises to strengthening his groin. There are lots of weight bearing exercises you can do to strengthen the groin -- sumo deadlift, wide stance box squats, squats, lateral squats, and I'm sure a gazillion others.
Second, get his groin used to deceleration again. The nervous system is going to remember the injury and will try to prevent it by limiting the body's exposure to that type of pressure again. So take time to get the groin used to stop -- just a little bit at a time till the brain feels comfortable with it.
Third, once he's working at game speed, work on body positioning drills to help him decelerate better -- this plyometrics, change of direction work, trying to replicate the game's demands as much as possible. These drills would help him drop his hips a bit, make sure the leg is partially loaded to absorb force, and probably teach his body to use his feet to absorb force as well. Or if he absolutely needs to get tall to throw the ball, work on him jumping (transferring force down in to the ground to push his body up) and then falling to the ground after he's thrown.
There is a lot to know and understand when it comes to training athletes to prevent injury (I'm working on getting there!). Understanding the basics of physics and human physiology is a good start. I'd love to work with your athletes to make them more resistant to injury, more explosive than the competition, and able to achieve their highest potential.