I'm 35. Yep, that's right, 35. I know that's not that old, but I'm not exactly built for a lot of physicality. When I played football in high school I was about 140 lbs and was a running back for a team that ran the ball about 50 times a game. For my breif stint in college football, I was a 155 lb reciever attempting to play division I with some of the best athletes in the country. In both places, I was the smallest guy out there and I got my tail kicked all over the field. I get a lot of silly nagging injuries and I attribute that to my time playing football and the fact that (saying in my little girl high pitched voice) I'm just a little guy. Throughout the years I've had two shoulder surgeries, a reverse curve in my neck, a slight case of spondylolysis (I think that's how it's spelled), and my knees are showing signs of fatigue. Oh yeah, and I have an undiagnosed rotator cuff injury on the other shoulder. The neck hurts every single day and the more I run the more I feel it.
I'm not talking about all of this to draw attention to myself. My point is that I have learned to take care of my joints. I wish I had half the knowledge of joint care that I had when I was a teenager that I have now. I recently graduated from the University of Louisville with my Master's Degree in Exercise Physiology. I took 4 semesters of classes, most of which were geared towards research and labwork. But my final class there was taught by the Director of Sports Performance and her team of strength coaches and it was easily the most useful class I took. It's that class that I truly learned about mobility and stability and importance of taking care of muscle imbalances and deficiencies before moving on to progressing to more advanced movements.
This way of looking at training is called the joint by joint approach and was first introduced by Gray Cook and Mike Boyle. In a nutshell, it says that your body is one kinetic chain of joints that all affect each other. If one goes bad, it is likely to cause problems in the joint above and/or below it. Each joint is either uniquely designed for stability or mobility. Ankle is mobile, knee is stable, hips are mobile, and so on. When this concept is truly understood, you can start applying numerous different exercises to help the deficient joint.
I have 2 issues. I have terrible ankle mobility and terrible thoracic spine mobility. The ankle mobility, or lack thereof, causes me to lean forward on squats which is hard on my lumbar spine and knees. My lack of t-spine mobility is the culprit of why my shoulders are torn apart. Since incorporating exercises to improve these areas, I have felt much better and have improved my mobility in those joints and stability in the surrounding joints. Recently, my knees have been a little sore from all of the running I'm now doing. It's more running than I have ever done. Even with the interval training, I'm still racking up the miles. So I really need to ensure I'm getting plenty of ankle and hip mobility training and knee stability training to ensure I keep everything moving smoothly. Believe me, a foam roller has become my best friend.
In a nutshell, take care of your joints. Below are several links to check out if you want to learn more about mobility and stability. Even the boys over at CrossFit have jumped on board with this and Kelly Sterrett is leading the way. It's something you need to pay attention to and incorporate in your training.