The most accurate way to determine the key joint actions and muscles involved in a strength exercise is to analyze biomechanically and kinesiologically, the movements that are performed. By doing this you can also determine the effectiveness of the exercise in relation to muscle involvement and function. Only in this way can you determine which joint actions and muscles play a major role and if the exercise is effective and safe.
In books and magazines exercises are usually described in very general terms. As a result it leads to misunderstandings. An exercise analysis, however, answers questions such as: If the exercise is effective, why is it effective? What is the role of each joint action? What is the role of the different muscles that are involved? With this information it is possible to determine which actions can be changed to make the technique more effective? Also, how can joint, body, or limb movements be changed to bring in greater involvement of specific muscles? How can specific actions be made more powerful? Should the exercise be modified? If the answer is yes, how can this be done? Most sources of standard instruction fail to address important points such as these.
There is a lack of agreement in regard to exercises and their execution among iron sport athletes, strength and conditioning coaches, athletes, personal trainers, and people who are involved in fitness programs. There is often disagreement when identifying the key actions and the exact execution that is needed to ensure safety and produce maximum strength or muscle involvement.
Nor is there conformity as to how each joint action involves specific muscles. Instead, we see articles espousing the opinions of exercisers, personal trainers, and celebrities which are often at odds with one another’s views. You have probably read articles dealing with certain issues, as for instance, whether the bar should be pulled down in front or behind the head when doing the lat pull-down. Or, if the arms should be raised shoulder level or completely overhead when doing the lateral or front arm raise, or if you should hold your breath on the exertion phase of a lift.
From biomechanics and kinesiology, that also incorporate pertinent physiological factors, we can come up with definitive answers to resolve these issues. These answers are based on science and facts, not opinion, as is often being done.
Biomechanics is the study of movement, more specifically, the movement (technique) involved in a strength exercise, or in execution of a sports skill. It deals mainly with physical factors such as speed, mass, acceleration, levers, force, and the physical functions of the movement. Some think of biomechanics as the science of movement based on principles derived from physics and anatomy. It explains the “why” and “how” of a movement and strategies to improve it through scientifically-based modifications.
Kinesiology is the study of human motion which deals mainly with the muscles and their functions. It describes movement, which muscles are involved in the movement, and how exactly they are involved. It explores the muscular involvement in strength exercises and sports technique while biomechanics looks at the physical factors involved in the movement.
By applying basic scientific laws it is possible to come up with accurate descriptions not only of what should take place in the exercise, but also the roles that key joint actions and muscles play. By studying the physical characteristics of the human body and the principles of mechanical physics, you will be able to better apply the information to your workouts or to those of your charges. You will have the basis for selecting and using specific exercises and movements to produce the results desired. Biomechanics and, to a limited extent, kinesiology are relatively new to the fitness and sports fields but are very important emerging sciences. They help to determine what exercises a person should do, how the workouts should be conducted, how effective the exercise execution is and if the exercises you use are safe. Biomechanics shows you the way to do exercises most effectively while kinesiology tells you which muscles are involved in the particular actions that take place in the exercise.