Ballistic movement can be defined as muscle contractions that exhibit maximum velocities and accelerations over a very short period of time. They exhibit high firing rates, high force production, and very brief contraction times.
The muscle contraction of a ballistic muscle movement can exhibit a muscle coactivation of concurrent agonist [1] and antagonist muscles or the characteristic triphasic agonist/antagonist/agonist muscle activation. [2] Electromyography (EMG) recordings of demonstrate the triphasic muscle activation begins with a brief agonist motor unit activation signal with firing rates of 60 to 120 Hz that may last for 100ms and occurs 50 to 100ms before movement begins. The firing rates of ballistic movements are much higher than that of slow ramp movements (5–15 Hz). The brief agonist muscle contraction is thus followed by antagonist muscle unit activation. The degree of antagonist muscle unit activation is dependent on the task at hand unlike the first agonist muscle activation which is independent to environmental stimuli. The function of the antagonist muscle contraction is believed to control the amplitude and timing of ballistic movements. Antagonist muscle contraction may serve to prevent injury to joints by preventing the limb from overextending itself and also function to control the distance and time the limb is being moved. Experiments involving ballistic movement of small amplitudes show a marked increase in antagonist muscle activation and experiments where distance moved is not controlled antagonist muscle activation was decreased or absent. [2] The second agonist muscle activation is suggested to terminate the negative acceleration of the antagonist muscle contraction and thus the ballistic movement.
Ballistic movements are often powered through elastic energy storage and subsequent recovery mechanisms. The power required to produce the extremely rapid velocities of ballistic movements is made possible through muscle work being stored in elastic elements (such as tendons, aponeuroses, or even muscle). Muscle work is applied to these elastic elements over a relatively slow period of time, and is released very rapidly. [3] Higher power output is produced because the energy is released in a much shorter amount of time than it is stored. In this sense the power of the muscles is actually amplified. When energy is produced by muscle contraction, stored in a tendon, then released to increase mechanical energy of the body (or body segment), muscle power is amplified. It is important to note, however, that the term power ‘amplification’ may be deceptive. In animals, elastic mechanisms never add energy to the system; they amplify power in the sense that the energy is released more rapidly than it is stored. [4]
Ballistic systems are capable of power outputs that are significantly greater than that of the muscles associated with the actual movement. One prime example of this is tongue projection in salamanders. [5] This decoupling of muscle work from body/limb work is a major benefit of elastic energy storage mechanisms. Another benefit resulting from this decoupling is decreased thermal dependence of ballistic movement. [6] Deban and Lappin analyzed the prey capture behavior of toads (Bufo terrestris), which involves two types of movement: elastically powered, ballistic movement (mouth opening and tongue projection) and muscle-powered movement (tongue retraction and mouth closing). The toad feeding was observed across a range of temperatures (11–35 °C), and the kinematic, dynamic, and electromyographic variables were measured and analyzed. Over the 11–35 °C temperature range, the ballistic movements had Q10 values very close to 1 (Q10 = 0.99–1.25), signifying thermal independence and supporting the main hypothesis. The muscle-powered movements had a higher temperature coefficient (Q10 = 1.77–2.26), signifying thermal dependence.
Another example of a thermally independent ballistic movement is tongue projection in chameleons. [7] It was discovered that veiled chameleons (Chamaeleo calyptratus) were able to perform this high-performance tongue projection, and successful prey capture, across a wide range of temperatures (15 °C–35 °C). Anderson and Deban also found a contrast between thermal dependence of tongue projection and retraction (which is not elastically-powered). This further supports the hypothesis that the elastic recoil mechanism is responsible for the decreased thermal dependence of ballistic tongue projection.
In trap-jaw ants (Odontomachus bauri) ballistic movement can be seen in their extremely rapid mandible strikes. The trap-jaw ants mandible has an average closing speed of 38.4 m/s and can produce forces that are 371-504 times the weight of the ant. The ants use these extremely powerful mandible strikes in several novel ways. When the ant attacks a larger animal it will strike the animal and at the same time use the force from the strike to propel itself away from the animal. When facing prey of similar size such as another ant the strike actually results in both animals being propelled away from each other. When the ant is trying to flee from a predator it will strike at the substrate and propel itself vertically into the air. [8]
In crickets (Acheta domesticus) ballistic movements can be seen in the way they jump. The kicks that propel the cricket occur over a period of only 2-6ms, but during the 18-40ms prior to the kick the potential energy required is built up by the co-contraction of the antagonistic extensor and flexor tibiae. The crickets can also use these same ballistic movements for swimming. [9]
In the cone snail (Conus catus) ballistic movement can be seen in the way that it fires is harpoon-like radular tooth into its prey. After the cone snail’s proboscis comes in contact with its prey the tooth is ejected 240-295 ms later. It is believed that the propulsion of the tooth is accomplished by pressurizing the fluid space behind the tooth. [10]
In Salamanders, Toads, and Chameleons ballistic movement can be seen in their tongue projection which is controlled by an elastic recoil mechanism. The orientation of the muscle fibers is significant because it is what allows ballistic movements to be possible. In chameleons, the muscle fibers used for ballistic tongue movements were found to be in a spiral orientation, with an equal amount of fibers oriented clockwise and anti-clockwise to prevent torsional movement of the tongue during projection. The internal fiber angles are approximately 45 degrees, which is the theoretical optimum to create an equal strain throughout the accelerator muscles. [11]
In salamanders of the genus Hydromantes, the pattern of muscle activation has been mapped. The main muscles used for ballistic tongue movements in these salamanders are the subarcualis rectus (SAR) muscles. These SAR muscles can be further divided into anterior (SARA) and posterior (SARP). The first muscle to be activated is the SARA, which is located near the back of the head. The SARA remains active until the tongue makes contact with the prey. Next, the posterior SARP, located further back on the medial and lateral sides of the salamander is activated. Then the middle SARP is activated and the anterior SARP is the last to be activated. The time between activation shortens and duration of activation increases with increasing prey distance. Ballistic tongues have evolved two times previously in the Hemidactyliini and Bolitoglossini genera. The exact mechanisms of tongue projection vary slightly throughout the taxa, but the resulting projections have remained relatively constant. [12]
Frogs do not have a specialized muscular structure for tongue projection. They are able to bypass this issue by using very rapid jaw movement to project the tongue forward. Present in all frogs are the two mandibular muscles that are used to control the jaw and, therefore, tongue projection. The m. genioglossus is used to protract the tongue and the m.hyoglossus is the tongue retractor. Both of these muscles have longitudinally oriented fibers, which is in contrast to the spiral oriented fibers of the chameleon. [13]
In human, ballistic movements involve spontaneous propulsion of the limbs. [14] This can be seen in daily routines such as reach and strike reactions, which are atomic by nature. Pointing gestures and placing an object are reach reactions; they have low acceleration and deceleration. On the other hand, punching and throwing are strike reactions; they are characterized by high acceleration and deceleration. These movements have highly variable target locations, and they are referred to as “ballistic” in kinesiology. During ballistic movement an initial impulse is needed to accelerate the limb (hand/foot) toward the target, then a decelerating impulse act as a brake to stop the movement. These movements are characterized by a bell-shaped velocity profile. The Bayesian Model (see Bayesian network), which was developed to perform recognition without pose-tracking, explains human ballistic movement as a sequence of movements between objects and the environment. Each movement is independent from precedent and subsequent one, in varying context. Fast single joints movement in humans is controlled by a series of activation of agonist, antagonist and then agonist muscles; this process is called triphasic activation. Those movements are executed “with a pattern of bursts in the agonist and antagonist muscles of fairly constant duration but different amplitude…” (Acornero et al. 1984). [15] Any ballistic movement involving two joints will require an agonist and an antagonist burst; this can be viewed as the building blocks for different types of ballistic movements.
Chameleons or chamaeleons are a distinctive and highly specialized clade of Old World lizards with 200 species described as of June 2015. The members of this family are best known for their distinct range of colors, being capable of shifting to different hues and degrees of brightness. The large number of species in the family exhibit considerable variability in their capacity to change color. For some, it is more of a shift of brightness ; for others, a plethora of color-combinations can be seen.
The American bullfrog, often simply known as the bullfrog in Canada and the United States, is a large true frog native to eastern North America. It typically inhabits large permanent water bodies such as swamps, ponds, and lakes. Bullfrogs can also be found in manmade habitats such as pools, koi ponds, canals, ditches and culverts. The bullfrog gets its name from the sound the male makes during the breeding season, which sounds similar to a bull bellowing. The bullfrog is large and is commonly eaten throughout its range, especially in the southern United States where they are plentiful.
Skeletal muscles are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle tissue, and are often known as muscle fibers. The muscle tissue of a skeletal muscle is striated – having a striped appearance due to the arrangement of the sarcomeres.
Muscle contraction is the activation of tension-generating sites within muscle cells. In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as when holding something heavy in the same position. The termination of muscle contraction is followed by muscle relaxation, which is a return of the muscle fibers to their low tension-generating state.
A muscular hydrostat is a biological structure found in animals. It is used to manipulate items or to move its host about and consists mainly of muscles with no skeletal support. It performs its hydraulic movement without fluid in a separate compartment, as in a hydrostatic skeleton.
Reciprocal inhibition describes the relaxation of muscles on one side of a joint to accommodate contraction on the other side. In some allied health disciplines, this is known as reflexive antagonism. The central nervous system sends a message to the agonist muscle to contract. The tension in the antagonist muscle is activated by impulses from motor neurons, causing it to relax.
The Q10 temperature coefficient is a measure of temperature sensitivity based on the chemical reactions.
In pathology, a contracture is a shortening of muscles, tendons, skin, and nearby soft tissues that causes the joints to shorten and become very stiff, preventing normal movement. A contracture is usually permanent, but less commonly can be temporary, or resolve over time but reoccur later in life.
Odontomachus bauri is a species of ponerinae ant known as trap jaw ants. The trap jaw consists of mandibles which contain a spring-loaded catch mechanism.
Muscle coactivation occurs when agonist and antagonist muscles surrounding a joint contract simultaneously to provide joint stability, and is suggested to depend crucially on supraspinal processes involved in the control of movement. It is also known as muscle cocontraction, since two muscle groups are contracting at the same time. It is able to be measured using electromyography (EMG) from the contractions that occur. The general mechanism of it is still widely unknown. It is believed to be important in joint stabilization, as well as general motor control.
Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey using sheer speed or endurance, ambush predators avoid fatigue by staying in concealment, waiting patiently for the prey to get near, before launching a sudden overwhelming attack that quickly incapacitates and captures the prey.
The three-lined salamander is a species of salamander in the family Plethodontidae. It is endemic to the south-eastern United States. Like other Plethodontidae species, E. guttolineata captures prey via tongue projection.
Myomeres are blocks of skeletal muscle tissue arranged in sequence, commonly found in aquatic chordates. Myomeres are separated from adjacent myomeres by connective fascia (myosepta) and most easily seen in larval fishes or in the olm. Myomere counts are sometimes used for identifying specimens, since their number corresponds to the number of vertebrae in the adults. Location varies, with some species containing these only near the tails, while some have them located near the scapular or pelvic girdles. Depending on the species, myomeres could be arranged in an epaxial or hypaxial manner. Hypaxial refers to ventral muscles and related structures while epaxial refers to more dorsal muscles. The horizontal septum divides these two regions in vertebrates from cyclostomes to gnathostomes. In terrestrial chordates, the myomeres become fused as well as indistinct, due to the disappearance of myosepta.
Undulatory locomotion is the type of motion characterized by wave-like movement patterns that act to propel an animal forward. Examples of this type of gait include crawling in snakes, or swimming in the lamprey. Although this is typically the type of gait utilized by limbless animals, some creatures with limbs, such as the salamander, forgo use of their legs in certain environments and exhibit undulatory locomotion. In robotics this movement strategy is studied in order to create novel robotic devices capable of traversing a variety of environments.
Role of skin in locomotion describes how the integumentary system is involved in locomotion. Typically the integumentary system can be thought of as skin, however the integumentary system also includes the segmented exoskeleton in arthropods and feathers of birds. The primary role of the integumentary system is to provide protection for the body. However, the structure of the skin has evolved to aid animals in their different modes of locomotion. Soft bodied animals such as starfish rely on the arrangement of the fibers in their tube feet for movement. Eels, snakes, and fish use their skin like an external tendon to generate the propulsive forces need for undulatory locomotion. Vertebrates that fly, glide, and parachute also have a characteristic fiber arrangements of their flight membranes that allows for the skin to maintain its structural integrity during the stress and strain experienced during flight.
Although projectiles are commonly used in human conflict, projectile use by organisms other than humans is relatively rare.
Normal aging movement control in humans is about the changes in the muscles, motor neurons, nerves, sensory functions, gait, fatigue, visual and manual responses, in men and women as they get older but who do not have neurological, muscular or neuromuscular disorder. With aging, neuromuscular movements are impaired, though with training or practice, some aspects may be prevented.
Elastic mechanisms in animals are very important in the movement of vertebrate animals. The muscles that control vertebrate locomotion are affiliated with tissues that are springy, such as tendons, which lie within the muscles and connective tissue. A spring can be a mechanism for different actions involved in hopping, running, walking, and serve in other diverse functions such as metabolic energy conservation, attenuation of muscle power production, and amplification of muscle power production.
A spinal interneuron, found in the spinal cord, relays signals between (afferent) sensory neurons, and (efferent) motor neurons. Different classes of spinal interneurons are involved in the process of sensory-motor integration. Most interneurons are found in the grey column, a region of grey matter in the spinal cord.
Anatomical terminology is used to uniquely describe aspects of skeletal muscle, cardiac muscle, and smooth muscle such as their actions, structure, size, and location.