Biomechanics
Biomechanics is the study of the body in a mechanical sense. This field attempts to make sense of the complexity of human movement by looking at the parts involved, analogous to the manner in which a car mechanic may explain how a vehicle works. The biomechanics of volleyball refers to the application of this field specifically to the movements in the sport.
The movements of Volleyball are a complex combination of strength, power, agility, and finesse. Each of these components is comprised of intricate, small movements, the summation of which are coordinated acts of striking the volleyball in a desired fashion. Due to the many aspects related to the biomechanics of volleyball, not every strike of the ball is perfect. Many times, mistakes made by athletes are due to the impossibility of executing hundreds of tiny movements perfectly every single time.
The complexity of the sport makes it impossible to explore every side of the biomechanics of volleyball here. It is helpful to instead focus on a few motions to gain a greater understanding of this field. A great example of the many aspects of volleyball can be outlined by reviewing the motions of the jump serve.
The jump serve requires an approach, jump, as well as shoulder and arm motion all working together to strike the ball at the right time in the proper manner. The list of muscles involved in these movements is very long. Among them are the quadriceps and hamstrings in the legs, deltoids in the shoulders, and triceps, biceps, and the muscles of the hand and forearm. A person studying the biomechanics of volleyball would be concerned with these and other related muscle groups.
American sports medicine institute: UPPER LIMB BIOMECHANICS DURING THE VOLLEYBALL SERVE AND SPIKE STUDY
I have found the results for a study done by the American Sports Medicine Institute, which was performed by Dr. Jonathan C. Reeser, PhD; Dr. Glenn S. Fleisig, PhD; Becky Bolt, MS; and Dr. Mianfang Ruan, PhD. This is a great explanation of the biomechanics of Volleyball.
Background: The shoulder is the third-most commonly injured body part in volleyball, with the majority of shoulder problems resulting from chronic overuse.
Hypothesis: Significant kinetic differences exist among specific types of volleyball serves and spikes.
Study Design: Controlled laboratory study.
Methods: Fourteen healthy female collegiate volleyball players performed 5 successful trials of 4 skills: 2 directional spikes, an off-speed roll shot, and the float serve. Volunteers who were competent in jump serves (n, 5) performed 5 trials of that skill. A 240-Hz 3-dimensional automatic digitizing system captured each trial. Multivariate analysis of variance and post hoc paired t tests were used to compare kinetic parameters for the shoulder and elbow across all the skills (except the jump serve). A similar statistical analysis was performed for upper extremity kinematics.
Results: Forces, torques, and angular velocities at the shoulder and elbow were lowest for the roll shot and second-lowest for the float serve. No differences were detected between the cross-body and straight-ahead spikes. Although there was an insufficient number of participants to statistically analyze the jump serve, the data for it appear similar to those of the cross-body and straight-ahead spikes. Shoulder abduction at the instant of ball contact was approximately 130° for all skills, which is substantially greater than that previously reported for female athletes performing tennis serves or baseball pitches.
Conclusion: Because shoulder kinetics were greatest during spiking, the volleyball player with symptoms of shoulder overuse may wish to reduce the number of repetitions performed during practice. Limiting the number of jump serves may also reduce the athlete’s risk of overuse-related shoulder dysfunction.
Clinical Relevance: Volleyball-specific overhead skills, such as the spike and serve, produce considerable upper extremity force and torque, which may contribute to the risk of shoulder injury.
Background: The shoulder is the third-most commonly injured body part in volleyball, with the majority of shoulder problems resulting from chronic overuse.
Hypothesis: Significant kinetic differences exist among specific types of volleyball serves and spikes.
Study Design: Controlled laboratory study.
Methods: Fourteen healthy female collegiate volleyball players performed 5 successful trials of 4 skills: 2 directional spikes, an off-speed roll shot, and the float serve. Volunteers who were competent in jump serves (n, 5) performed 5 trials of that skill. A 240-Hz 3-dimensional automatic digitizing system captured each trial. Multivariate analysis of variance and post hoc paired t tests were used to compare kinetic parameters for the shoulder and elbow across all the skills (except the jump serve). A similar statistical analysis was performed for upper extremity kinematics.
Results: Forces, torques, and angular velocities at the shoulder and elbow were lowest for the roll shot and second-lowest for the float serve. No differences were detected between the cross-body and straight-ahead spikes. Although there was an insufficient number of participants to statistically analyze the jump serve, the data for it appear similar to those of the cross-body and straight-ahead spikes. Shoulder abduction at the instant of ball contact was approximately 130° for all skills, which is substantially greater than that previously reported for female athletes performing tennis serves or baseball pitches.
Conclusion: Because shoulder kinetics were greatest during spiking, the volleyball player with symptoms of shoulder overuse may wish to reduce the number of repetitions performed during practice. Limiting the number of jump serves may also reduce the athlete’s risk of overuse-related shoulder dysfunction.
Clinical Relevance: Volleyball-specific overhead skills, such as the spike and serve, produce considerable upper extremity force and torque, which may contribute to the risk of shoulder injury.
what is muscle memory?
Muscle memory can best be described as a type of movement with which the muscles become familiar over time. For instance, newborns don’t have muscle memory for activities like crawling, scooting or walking. The only way for the muscles to become accustomed to these activities is for the baby to learn how to do these things and then practice them with a great deal of trial and error. Gradually, as the baby becomes a skilled walker, he falls less, is able to balance, and finally is able to incorporate other activities into his life such as running.
Although the precise mechanism of muscle memory is unknown, what is theorized is that anyone learning a new activity, or practicing an old one has significant brain activity during this time. The walking child is gradually building neural pathways that will give the muscles a sense ofmuscle memory. In other words, even without thinking, the child is soon able to walk, and the muscles are completely accustomed to this process. The child doesn’t have to tell the body to walk; the body just knows how to do it, largely because neurons communicate with the muscles and say, “walk now.”
Although the precise mechanism of muscle memory is unknown, what is theorized is that anyone learning a new activity, or practicing an old one has significant brain activity during this time. The walking child is gradually building neural pathways that will give the muscles a sense ofmuscle memory. In other words, even without thinking, the child is soon able to walk, and the muscles are completely accustomed to this process. The child doesn’t have to tell the body to walk; the body just knows how to do it, largely because neurons communicate with the muscles and say, “walk now.”
How does muscle memory relate to volleyball?
Muscle memory relates to Volleyball in many ways. Take your footwork when you serve for example. Left step, toss, right step, hit. Left, toss, right, hit. Left, toss, right, hit. Just like that your muscles and brain memorize this movement, especially after doing it over and over again in practice. It doesn't take but a few practices before your muscles just "get the hang of it". The same thing happens when you're spiking the ball. Your muscles, and brain, get so used to you practicing your approach you don't even have to think about it. Left foot, big step, arms extended back, right foot, guide arm up, left foot, jump, guide, hit! This may sound complicated but after doing it over and over again your muscles, just memorize it. Passing the ball to your setter uses the same concept. An experienced volleyball player's arms will automatically extend and her feet shuffle over to pass the ball to her setter naturally when a passable ball is coming at her, without even thinking hard about it. Just like with any sport your brain, and muscles, memorize your techniques, but why?
How does muscle memory work?
Muscle memory is an informal way of referring to the acquisition of automatic and coordinated motor skill, and does not involve the muscles actually remembering anything. The memories are stored in the brain.
Several parts of the nervous system work together to learn and execute automatic smooth coordinated motor action. While interactive reflexes are implemented as low-level as the spinal cord, learned automatic coordinated motor skill (muscle memories) are represented in the brain.
How motor skills are represented and allocated across brain regions is still the subject of ongoing research, however the basal ganglia in the interior of the brain has emerged as a region of particular interest. The basal ganglia seems to be responsible for learned automatic and habitual action, although all complex motor skill, and especially voluntary goal-directed action, makes extensive use of the motor cortex (part of the cerebral cortex). The cerebellum is critical for learned smooth motor coordination.
Fine motor coordination relies heavily on proprioceptive feedback -- sensory input that tells the spinal cord and brain about joint angles and muscle resistance. Often these reflex circuits respond without learning at the level of the spinal cord, however the spinal circuits can be modulated by downward signals from the brain, which may allow them to be dynamically "reprogrammed" during the execution of complex feedback-controlled motor patterns.
Here is the basic brain circuit for sensorimotor control. (V1 = visual cortex; S1 = somatosensory cortex for touch; M1 = motor cortex; PF = prefrontal cortex for action goals and planning; BG = basal ganglia for automatic action; C = cerebellum for smooth coordination; VN = vestibular nuclei for balance. From Scott SH, 2004,Nature Reviews Neuroscience):
Several parts of the nervous system work together to learn and execute automatic smooth coordinated motor action. While interactive reflexes are implemented as low-level as the spinal cord, learned automatic coordinated motor skill (muscle memories) are represented in the brain.
How motor skills are represented and allocated across brain regions is still the subject of ongoing research, however the basal ganglia in the interior of the brain has emerged as a region of particular interest. The basal ganglia seems to be responsible for learned automatic and habitual action, although all complex motor skill, and especially voluntary goal-directed action, makes extensive use of the motor cortex (part of the cerebral cortex). The cerebellum is critical for learned smooth motor coordination.
Fine motor coordination relies heavily on proprioceptive feedback -- sensory input that tells the spinal cord and brain about joint angles and muscle resistance. Often these reflex circuits respond without learning at the level of the spinal cord, however the spinal circuits can be modulated by downward signals from the brain, which may allow them to be dynamically "reprogrammed" during the execution of complex feedback-controlled motor patterns.
Here is the basic brain circuit for sensorimotor control. (V1 = visual cortex; S1 = somatosensory cortex for touch; M1 = motor cortex; PF = prefrontal cortex for action goals and planning; BG = basal ganglia for automatic action; C = cerebellum for smooth coordination; VN = vestibular nuclei for balance. From Scott SH, 2004,Nature Reviews Neuroscience):