What is Biomechanics?
Biomechanics evaluates the motion of a living organism and the action of forces upon it. In the strength and conditioning, biomechanics can be looked at as the study of how the body moves and what causes movement either internally (via muscles) or externally (via external load or added weight bearing activities). Biomechanics is simply the application of the Laws of Physics to the human body.
Why are we concerned about Biomechanics?
If you were to pick up a sports biomechanics textbook, it would most likely say there are two primary goals for biomechanics: performance enhancement and injury prevention/rehabilitation. Biomechanics enhances performance by utilizing mechanical principles to improve an individual’s technique, the equipment they use and to modify specific training protocols that the coach implements to help an individual achieve their goals. Similarly, for injury prevention and rehabilitation, biomechanics is used to develop techniques that reduce the chance of injury as well as changes in equipment design to reduce injury. Compare that with the goals of biomechanics. They are virtually the same – reach goals (performance enhancement) the most efficient, effective and safest (injury prevention) way possible! Think about what we’ve learned so far. When we move, our nervous system instructs our muscles to contract. These contractions cause bones to move around the axes of joints. For this reason, our bodies can be viewed as a series of levers (bones) which rotate around an axis (joints) under the direction of a force (muscular contraction). When working with an athlete, we have a responsibility to not only guide them to their goals, but to do so in a safe and effective manner. It is vital to have some understanding of how the human body is meant to move and more importantly, which movements to avoid and why. If a coach does not understand these fundamental principles, their workouts will be inefficient and potentially dangerous. Our primary concern as strength coaches should always be to give everyone the greatest benefit with the least amount of risk.
Biomechanics – a NEW way of looking at exercise
One of the primary goals of this article is to empower you with a solid foundation in biomechanics. Another is to introduce you to a new way of looking at exercise in general. This is new perspective is:
Exercise is simply a mechanical stress placed on the body to which the body will adapt.
In order to understand this new perspective and its importance, one must be willing to accept several premises.
The primary physiological effects of exercise (both good and bad) are in direct response to the mechanical stress placed on the body.
Hans Selye’s GAS Theory shows us that the body will undergo adaptations when it is stressed. Exercise can be seen as a mechanical stress (Force/Area), placed on the body where the body must accept forces from external sources and respond by creating the appropriate internal forces (from the muscles and connective tissue) to create the appropriate movement. The stimulus of these stressors (both externally and internally), stimulate the physiological adaptations within the body. These physiological adaptations may be structural (adaptations to connective tissue such as muscle, bone and fascia) or functional (neuromuscular adaptations – i.e. motor learning).
In order to facilitate the proper adaptations for athletes coaches must understand forces, how they are applied (how much, in what direction, over what range of motion and at what speed), and how the tissues of the body will adapt to those forces.
Put simply, understanding forces and their effects is at the core of all physical training programs. Remember, there are forces on us all the time (whether something is moving or not). And if there is movement, there’s a force that caused that movement.
Proper understanding and implementation of biomechanics is essential in all aspects of training (Assess – Design – Instruct).
When you reach the assessment section, you will find that much of the assessment process consists of postural and movement assessments. Put simply, these are biomechanical assessments (looking at how an athlete’s body adapts to forces over time). These assessments might indicate certain kinetic chain imbalances (short/tight muscles on one side of a joint) that need to be addressed.
As previously stated, understanding how the body is going to adapt to the biomechanical stress you place upon it is essential to program design. The exercises chosen (and how they will be implemented) are based on the athlete’s goals and needs, level of training (training/chronological age, experience), and your knowledge of how to make them adapt safely and efficiently. Lastly, exercise instruction – the area where most strength coaches associate the importance of biomechanics. Put simply, understanding basic biomechanics is the basis of instructing proper technique.
How do we use Biomechanics to Maximize Performance and Minimize Chance of Injury?
There is a systematic thought process that every coach must utilize in order to ensure that their athletes are getting the most of every rep in every set.
What do we analyze?
When we evaluate an athlete’s technique, we are doing a biomechanical analysis (remember – every rep of every set is an assessment). You should be able to distinguish between what is important and what is unimportant, what is correct/incorrect, what is possible/impossible, what is effective/ineffective, what is safe/unsafe, etc. The first thing to evaluate and understand is the movement itself, without regard to the forces that caused it. In physics, this is known as Kinematics i.e. the direction of motion, the path of motion, and the range of motion.
Futhermore, a kinematic analysis might include basic kinematic variables such as distance, speed and acceleration (which you will learn shortly). Only after you analyze the kinematics to you look at the forces that cause the movement (as well as other forces on the body). In physics, this is known as kinetics.
Another way of looking at the analysis process is to look at joints first (both static and dynamic and describing them kinematically), then the external and internal forces on the body (kinetics). Muscles are engineered to move joints in a particular fashion (based on the structure of the joint). A basic understanding of joint structure and function is essential for proper muscle activation (i.e. if we are moving the joints properly, then the muscles must be working properly). Furthermore, we don’t really know which internal forces are developed without first looking at the external forces that caused it.
By Tom Delong