Topic 10 –Qualitative Biomechanical Analysis
Lesson Learning Outcomes
- Differentiate between technical and physical training.
- Understand how the results of qualitative analysis can improve technique and training methods.
- Be able to qualitatively evaluate a technical skill in sport.
- Describe the steps involved in a qualitative anatomical analysis.
- Identify the active muscle groups during any phase of movement and be able to recognize the muscle action.
Guiding Questions
- What are the steps involved in conducting a qualitative biomechanical analysis and what equipment are needed?
- Am I able to translate this information into a sporting situation as a coach/teacher?
- How is qualitative analysis different from quantitative analysis?
Biomechanics and Training
A fundamental principle of training is the principle of specificity. Exercises and drills must be specific to the sport or activity. If the exercises and drills you use in training closely match the aspects of the skill you are training for, you will have greater gains in performance. For some sports or activities, the type of training that is specific to the sport or activity is obvious. If you want to run a marathon, your training should consist primarily of running long distances. In other cases, the training exercises that are specific to the sport or activity may not be as obvious. For example, the specific strengths needed to be successful in pole vaulting are not obvious to the casual observer. Biomechanics can contribute to the improvement of training by identifying the specific technical or physical requirements necessary to perform a skill well..
Technical Training
Practice and training time for specific sport or movement activities is usually devoted to improving technique (technical training) or physical condition (physical training).
Biomechanics can contribute to improvements in technical training in several ways. First, a qualitative biomechanical analysis of an actual performance can identify deficiencies in technique. Another way biomechanics can contribute to improving technical training is by identifying exercises and drills that closely simulate the specific technical aspects of the skill.
Physical Training
Physical training is the other part of training. Whereas technical training is directed primarily at correcting or improving aspects of technique, physical training is directed at altering performance limitations due to the physical condition of the performer. Be aware that there is usually some overlap between the two types of training. Technical training may have some effect on the performer’s physical condition, and physical training may have some effect on the performer’s technical proficiency. In any case, physical training is directed at improving the
components of physical fitness, including
- Muscular strength
- Muscular power
- Muscular endurance
- Flexibility
- Aerobic fitness
- Body composition
Biomechanical analysis of an activity can identify the specific muscle groups whose strength, power, endurance, or flexibility limits performance. Specific exercises can then be chosen that strengthen or stretch these specific muscle groups. Likewise, a biomechanical analysis of an exercise can identify if the muscles used in the exercise are those used in the sport or activity.
Qualitative Anatomical Analysis Method
The purpose of a qualitative anatomical analysis is to determine the predominant muscular activity during specific phases of a performance and to identify instants when large stresses may occur due to large muscle forces or extremes in joint ranges of motion. The teacher or
coach may complete such an analysis on a student or on an elite performer who demonstrates effective technique. The analysis of the elite performance identifies which muscles are involved in performance of the most effective technique, whereas the analysis of the student identifies the muscles used in performing the specific technique. In either case, the methods used to identify the muscles involved are the same.
The following are step-by-step procedures for completing a qualitative anatomical analysis:
- Divide the activity into temporal phases.
- Identify the joints involved and the movements occurring at those joints.
- Determine the type of muscular contraction (concentric, eccentric, or isometric) and identify the predominant active muscle group at each joint.
- Identify instances when rapid joint angular accelerations (rapid speeding up or slowing down of joint motions) occur and where impacts occur.
- Identify any extremes in joint ranges of motion.
The results of a qualitative anatomical analysis can then be used to determine appropriate strength or flexibility exercises for the muscle groups identified.
Temporal Phases
The first step of a qualitative anatomical analysis is to break down the performance into specific phases or motions. For the simplest movements, such as slow movements or those that involve raising and lowering, the end of one phase and the beginning of the next may simply be designated by the change in direction of movement.
For example, let’s look at a bench press. The bench press involves two phases: the down phase, in which the lifter lowers the barbell to the chest, and the up phase, in which the lifter raises the barbell.
In contrast, faster, more complex movements may require breakdown into more phases than are obvious. The phases of a baseball pitch include the windup, delivery, and follow-through, but breaking the pitch into only these three phases may not provide enough detail about the joint motions to allow determination of the muscle activity that occurs.
Joint Motions
Once the performance has been broken down into specific phases or recorded on video, the next step is to identify which body segments and joints to examine. Which segments and joints are involved in the performance of the skill? Which segments move, and which joints are involved in the movements? For skills involving gross movement of the whole body, most of the major joints are involved. For example, running involves the ankle, knee, hip, shoulder, and elbow joints on either side of the body.
Once the segments and joints involved in the activity have been identified, the next step is to identify the motions occurring at each joint during each phase of the activity. Is flexion or extension occurring at the joint? Abduction or adduction? Internal or external rotation?
In a qualitative anatomical analysis, we are interested in joint motion, not joint position.
Muscle Contractions and Active Muscle Groups
The next step in a qualitative anatomical analysis is to determine what types of muscle contractions occur within the active muscle groups crossing each joint and to identify these active muscle groups.
Identifying the active muscle groups is simple once the type of muscular contraction has been determined. If the contraction has been identified as concentric, the active muscles are those that create torque in the same direction as the observed joint motion. For instance, if the observed joint motion is flexion and the contraction is concentric, the flexor muscles are active at that joint (the opposing extensor muscles might be active as well, but the resultant torque is a flexor torque, so the flexor muscles must produce greater torque).
Rapid Joint Angular Acceleration and Impacts
After identification of the active muscle groups, the next task in a qualitative anatomical analysis is to identify any instances when rapid joint angular accelerations and impacts occur. This task identifies the active muscle groups that must produce the largest forces as well as the positions of the limbs when these large forces must be produced. These are the muscle groups whose strength will be tested and the muscle groups that must be trained.
Extreme Joint Ranges of Motion
The last step in a qualitative anatomical analysis is to identify any extremes in joint ranges of motion. The purpose of this step is to identify those muscles and soft tissues that may be stretched and possibly injured. Flexibility exercises may be appropriate for these muscle groups. As with the previous step, this step is more important when we are analyzing fast movements.
Visual Representation of Anatomical Qualitative Analysis
Keeping track of what has been identified in each step of a qualitative anatomical analysis is difficult without a record of what you have identified in the previous steps. This job can be easier if you make a chart or table of the results of each step of the analysis. The chart might
include columns for the phases of the movement (or the frames of video), the joints analyzed, the joint motions, the muscle contractions, the active muscle groups, the rapid joint angular accelerations or impacts, and the extreme joint ranges of motion.
Shown below are some examples how how this chart may look like for different exercise movements and sports skills.
SUMMARY
- Biomechanics can be used to improve performance by improving training for that performance.
- A basic principle of training is specificity – Biomechanics can improve the specificity of training by identifying specific aspects of technique that need to be perfected.
- The five steps involved in a qualitative anatomical analysis are :
- Divide the activity into temporal phases.
- Identify the joints involved and their motions.
- Determine the type of muscular contraction (concentric, eccentric, or isometric) and the predominant active muscle group at each joint.
- Identify instances when rapid joint angular accelerations (rapid speeding up or slowing down of joint motions) occur and where impacts occur.
- Identify any extremes in joint ranges of motion.