INTERDISCIPLINARY TRAINING FOR ATHLETES
Biomechanics is a relatively new scientific discipline within the field of Kinesiology and it is thus understandable when people are unsure of its study.
So what exactly is Biomechanics? It is the science that examines forces acting upon and within biological structures and the effects produced by these forces (Nigg, B, et. al, 2007). This definition allows Biomechanists’ to study a broad spectrum of varying topics. Some scientists concern themselves with things such as muscle mechanics, telemetry, human locomotion or sport biomechanics but the thing that makes biomechanics unique is that there is interdependence amongst other scientific studies such as Physiology, Engineering, Physics, and Anatomy which make its survival paramount. Once we acknowledge this fact we are given insight into methods of more efficient training protocols for our athletes.
The interesting thing with the Olympics literally just around the corner is that drug scandals have become very much a part of the games we love and enjoy to watch. I’m not going to sit here and say that drugs are either right or wrong, but the fact of the matter is, if we want to eliminate any unfairness at the starting line we would have to ensure that each athlete had the same training environment, same training methodology and same upbringing. Obviously, that is going to lead us down a never ending debate about how we form the rules when it comes to performance enhancing drugs.
Now, let’s suppose drugs weren’t an issue in sport, what are some other ways we as coaches and athletes could improve competition day performance?
Probably the first thing that comes to mind is training our physiological systems by means of aerobic and anaerobic strength training and analyzing our nutrition. The problem with this is that our genetics will only allow us to go so far. For instance, it doesn’t matter how long, how hard I train or how many vegetables I eat, I will never be able to beat Usain Bolt in the 100m sprint. I will touch more on this later when I talk about muscle mechanics, but the fact of the matter is my muscle fibre type is composed of too many Type I fibres which are better suited for more endurance situations.
Pretend now that we’ve figured out which type of sport our bodies are best designed for; sprint, middle or endurance events, what are the ways we can further improve our ability? An area I am big on, but is often overlooked by many athletes, is their psychology. If we can figure out a way to master our thoughts in stressful competitive situations, then it goes without saying that we should be able to improve our performance. There have been studies that show just by visualizing your performance the same neural pathways we use during competition are primed as if you were doing your event live.
Let’s take this one step further. If we’ve identified our sport of choice, we’re not using performance enhancing drugs, our diets are balanced and we have a fairly good grasp of our mental abilities, there really only leaves one area for improvement in our performance, which is our technique or mechanics. If we look back to the 2004 Olympic Games at the 800m event the margin for victory was less than 0.71 seconds. If we take a look at all the major PGA events over the past 25 years, the average margin of victory is less than 3 strokes. I could go on and on about small margins of victory but I’m sure we can all appreciate how small differences can make dramatic effects. I’m not about to say that all victories are due to biomechanical and technical abilities of the athlete, but I will venture to say that in the heat of the moment during competition there are no successful athletes who are thinking about their technique as they race for a breakaway in hockey or sprint the last 500 meters in a cycling race. You’re thinking about the prize at the end of the line! We know that the most successful athletes don’t spend their focus and energy during competition on the position of their limbs in space or how their muscles are contracting and at what precise moment, which is exactly why it’s so important to take time during your off season training to work on the specific mechanics of your sport.
If we look at things on a microscopic level you will really begin to see how the study of Biomechanics is truly interdisciplinary.
“Whenever we move as humans we use our muscles to direct forces onto our bones which act as levers and together with other biological structures we are able to achieve locomotion.”
But before this can happen, there is a series of chemical reactions that take place within our neural pathways before terminating in our muscle fibres and are controlled by our Central Nervous System. To give you a better understanding of the process I am going to elaborate on the architecture of the muscle itself. Our muscles are organized into thousands of myofibrils; these myofibrils are composed of millions of repeating units called sarcomeres. Sarcomeres are the functional units for muscles and when we speak about muscular contraction it is the action at the level of the sarcomere that produces our mechanical changes. Each sarcomere is composed of contractile proteins called Actin and Myosin which attach to each other and form a cross-bridge through the chemical processes mentioned above. Once attached and in the presence of ATP, these molecules are able to slide past one another which decreases the length of the sarcomere and we have muscular contraction. This is the current paradigm for muscular contraction amongst biomechanists and physiologists which is referred to as the “Sliding Filament Theory”.
The importance of this theory is that it allows us to look at force production from each sarcomere in something called the “Force/Length Relationship”. This relationship shows us that each sarcomere has an optimal range at which peak tension can be achieved. If the sarcomere length lies outside this range, peak force begins to decrease. This is the fundamental basis for any technique/biomechanical training of athletes. If we look at a cyclist, for example, when their seat is too high they are not able to generate enough muscular tension during the power phase because there are not a maximum number of cross bridges formed. Imagine now that your seat was too low, during that power phase of the stroke there are too many overlapping cross bridges which actually hinder force development and the possibility of injury exists. Therefore, proper muscle and joint alignment for whatever your sport may be is crucial for optimizing force production and success as an athlete.
We can now subsequently examine the rate at which each contraction takes place. Looking at the definition of Power we can see that it is the product of Force x Velocity. When maximal force is being generated no velocity can occur, and power is zero. Conversely, when velocity is at a maximum there will be no force generated and again power will be zero. Optimal shortening velocity for power generation has been found to be approximately one third maximum shortening velocity. This has important applications and consequences for things like limiting running speed and the height and distance we can jump.
Where the cross reliance between scientific disciplines comes into play is when we look at muscle fibre types. The two main types of muscle fibres are Type I fibres (slow twitch) & Type II (fast twitch) with some intermediate fibres possessing both slow and fast twitch properties. Our Type II fibres are the ones we rely on to generate peak forces at high speeds. A sprinter, for example, would have a high distribution of Type II fibres in his body. On the other hand, our Type I fibres generate lower peak forces; however, they are more efficient and can be recruited for a longer period of time, such as in a Triathlon race. This is where exercise physiologists do their best work. Here they are able to implement training programs for athletes enabling their muscles to contract at faster rates with greater resistance and specifically target the appropriate muscle fibre types most beneficial for that athlete’s success.
To conclude this lengthy discussion, we can reliably say that each area of sport science has its appropriate place but in order to allow athletes to reach their full potential there must be cooperation between disciplines which has the athlete’s best interests at heart. It would be naive to think that one coach specializing in one area is the primary reason for athletic success. Take Lance Armstrong for example. He probably has an exercise physiologist to train his muscular development, a nutritionist to help him eat properly, an engineer who designed his bike, helmet and shoes and a biomechanist to put him in the optimal position on his bike (although I’m sure Chris Carmichael is able to do a majority of that himself!) However you slice it though, if you’re missing one key ingredient while baking a cake you’ll be left with soup. The same can be said for athletes. If they’re missing any key aspect of their training, whether it is physiologically or mechanically, you’re going to have an unprepared athlete!
Adam Redmond
November 2009
