Motor patterns of labriform locomotion: kinematic and electromyographic analysis of pectoral fin swimming in the labrid fish Gomphosus varius

1997 ◽  
Vol 200 (13) ◽  
pp. 1881-1893 ◽  
Author(s):  
M Westneat ◽  
J Walker

Labriform locomotion is a widespread swimming mechanism in fishes during which propulsive forces are generated by oscillating the pectoral fins. We examined the activity of the six major muscles that power the pectoral fin of the bird wrasse Gomphosus varius (Labridae: Perciformes). The muscles studied included the fin abductors (arrector ventralis, abductor superficialis and abductor profundus) and the fin adductors (arrector dorsalis, adductor superficialis and adductor profundus). Our goals were to determine the pattern of muscle activity that drives the fins in abduction and adduction cycles during pectoral fin locomotion, to examine changes in the timing and amplitude of electromyographic (EMG) patterns with increases in swimming speed and to correlate EMG patterns with the kinematics of pectoral fin propulsion. EMG data were recorded from three individuals over a range of swimming speeds from 15 to 70 cm s-1 (1­4.8 TL s-1, where TL is total body length). The basic motor pattern of pectoral propulsion is alternating activity of the antagonist abductor and adductor groups. The downstroke is characterized by activity of the arrector ventralis muscle before the other abductors, whereas the upstroke involves nearly synchronous activity of the three adductors. Most EMG variables (duration, onset time, amplitude and integrated area) showed significant correlations with swimming speeds. However, the timing and duration of muscle activity are relatively constant across speeds when expressed as a fraction of the stride period, which decreases with increased velocity. Synchronous recordings of kinematic data (maximal abduction and adduction) with EMG data revealed that activity in the abductors began after maximal adduction and that activity in the adductors began nearly synchronously with maximal abduction. Thus, the pectoral fin mechanism of G. varius is activated by positive work from both abductor and adductor muscle groups over most of the range of swimming speeds. The adductors produce some negative work only at the highest swimming velocities. We combine information from pectoral fin morphology, swimming kinematics and motor patterns to interpret the musculoskeletal mechanism of pectoral propulsion in labrid fishes.

2000 ◽  
Vol 203 (7) ◽  
pp. 1241-1252 ◽  
Author(s):  
B.C. Jayne ◽  
M.W. Daggy

Although lateral axial bending is widespread for the locomotion of ectothermic vertebrates, the axial motor patterns of terrestrial taxa are known only for a limited number of species and behaviors. Furthermore, the extent to which the trunk and tail of ectothermic tetrapods have similar motor patterns is poorly documented. We therefore recorded the activity of the epaxial muscles in the trunk and tail of sand-swimming Mojave fringe-toed lizards (Uma scoparia) to determine whether this specialized behavior has features of the motor pattern that differ from those of diverse ectothermic vertebrates. Muscle activity during initial sand-swimming was a standing-wave pattern in the trunk and tail. Next, the hind limbs moved alternately and the caudofemoralis muscles and nearby axial muscle in the trunk and tail had similar long-duration electromyographic bursts, whereas the anterior trunk had shorter, more frequent electromyographic bursts. The final tail burial involved a traveling wave of posteriorly propagated axial muscle activity within localized regions of the tail. With increased temperature (from 22 to 40 degrees C), the mean frequencies of axial oscillations increased from approximately 7 to 21 Hz, and the greatest value (33 Hz) was nearly twice the maximal limb cycling frequency during running. The mean burial time at the lowest temperature (3.8 s) was nearly twice that for a 10 degrees C higher temperature. For the axial electromyograms, a decrease in temperature of 18 degrees C more than doubled the electromyographic and cycle durations, whereas the duty factors and intersegmental phase lags changed only slightly with temperature.


1999 ◽  
Vol 202 (24) ◽  
pp. 3523-3539 ◽  
Author(s):  
L.J. Rosenberger ◽  
M.W. Westneat

Rajiform locomotion is a unique swimming style found in the batoid fishes (skates and rays) in which thrust is generated by undulatory waves passing down the enlarged pectoral fins. We examined the kinematic patterns of fin motion and the motor patterns of pectoral fin muscles driving the locomotor system in the blue-spot stingray Taeniura lymma. Our goals in this study were to determine overall patterns of fin motion and motor control during undulatory locomotion, to discover how these patterns change with swimming velocity and to correlate muscle function with kinematics and pectoral morphology. Kinematic data were recorded from five individuals over a range of swimming speeds from 22 to 55 cm s(−)(1) (0.9-3.0 DL s(−)(1), where DL is body disc length). Electromyographic (EMG) data were recorded from three individuals over a range of velocities (1.2-3.0 DL s(−)(1)) at seven locations (four dorsal, three ventral) along the pectoral fin. As swimming velocity increases, fin-beat frequency, wavespeed and stride length increase, number of waves and reduced frequency decrease and fin amplitude remains constant. There is variability among individuals in frequency and amplitude at a given speed. An inverse relationship was found in which a high fin-beat frequency is associated with a low fin amplitude and a low fin-beat frequency is associated with a high fin amplitude. The motor pattern of undulatory locomotion is alternate firing activity in the dorsal and ventral muscles as the wave moves along the fin from anterior to posterior. Fin muscles are active along the entire length of the fin except at the lowest speeds. As swimming velocity and fin-beat frequency increase, the time of activation of posterior muscles becomes earlier relative to the onset of activity in the anterior dorsal muscles. The duration of muscle activity is longer in the ventral muscles than in the dorsal muscles, indicating that they play a central role in the power stroke of the fin-beat cycle. The anterior muscles (dorsal and ventral) are active for a relatively longer part of the stride cycle than the posterior muscles. Both the anterior position and the large duty factor of the anterior muscles reflect the role of these muscles in initial wave generation. Synchronous recordings of kinematic data with EMG data reveal that the anterior dorsal and middle ventral muscles do mostly positive work, whereas the dorsal and ventral posterior muscles do negative work at most swimming speeds.


1989 ◽  
Vol 141 (1) ◽  
pp. 359-375 ◽  
Author(s):  
PETER C. WAINWRIGHT

This study examines patterns of variation in 15 electromyographic (EMG) variables measured from recordings of pharyngeal jaw muscle activity during prey processing in four species of the perciform fish family Haemulidae. Two questions were of primary interest. (1) Are motor patterns conserved across the four species? (2) Do the fishes alter (modulate) muscle activity patterns when feeding on different prey types? The experimental design used allowed the partitioning of variance in EMG variables among species, among individuals within species, among days within individuals, among feedings within days, and among prey types. Only one variable exhibited a significant species effect, indicating that the four species used virtually the same motor pattern during prey processing. In response to three prey types differing in hardness, all four species demonstrated an ability to modulate several EMG variables that characterized the intensity of electrical activity. However, variables characterizing the relative timing of muscle activities were not influenced by prey type. A significant variance component was found among recording days and, together with the possibility of variation among experimental preparations, this raises questions about the extent of previously reported inter-individual variation in EMGs. These results support a growing data base on aquatic feeding in lower vertebrates which finds that: (1) motor patterns tend to be highly conserved among closely related taxa; (2) the ability to modulate motor patterns in response to different prey types appears to be a general property of teleost fish feeding mechanisms; and (3) variation in experimental EMG data is ubiquitous and, when unaccounted for, confounds comparisons among treatment groups.


2000 ◽  
Vol 203 (18) ◽  
pp. 2781-2796 ◽  
Author(s):  
C.D. Wilga ◽  
P.J. Motta

This study investigates the motor pattern and head movements during feeding of a durophagus shark, the bonnethead Sphyrna tiburo, using electromyography and simultaneous high-speed video. Sphyrna tiburo feeds almost exclusively on hard-shelled crabs, with shrimp and fish taken occasionally. It captures crabs by ram feeding, then processes or reduces the prey by crushing it between molariform teeth, finally transporting the prey by suction for swallowing. The prey-crushing mechanism is distinct from that of ram or bite capture and suction transport. This crushing mechanism is accomplished by altering the duration of jaw adductor muscle activity and modifying jaw kinematics by the addition of a second jaw-closing phase. In crushing events, motor activity of the jaw adductor muscles continues (biting of the prey occurs as the jaws close and continues after the jaws have closed) throughout a second jaw-closing phase, unlike capture and transport events during which motor activity (biting) ceases at jaw closure. Sphyrna tiburo is able to take advantage of a resource (hard prey) that is not readily available to most sharks by utilizing a suite of durophagous characteristics: molariform teeth, a modified jaw protrusor muscle, altered jaw adductor activity and modified jaw kinematics. Sphyrna tiburo is a specialist feeder on crab prey as demonstrated by the lack of differences in kinematic or motor patterns when offered prey of differing hardness and its apparent lack of ability to modulate its behavior when feeding on other prey. Functional patterns are altered and coupled with modifications in dental and jaw morphology to produce diverse crushing behaviors in elasmobranchs.


1993 ◽  
Vol 180 (1) ◽  
pp. 209-227 ◽  
Author(s):  
P. C. Wainwright ◽  
R. G. Turingan

Teleost fishes typically capture prey with the oral jaws and perform most types of prey- processing behavior with the pharyngeal jaw apparatus. In these fishes, the motor patterns associated with the different stages of feeding are quite distinct, and fish can modify muscle activity patterns when feeding on different prey. We examined motor pattern variation in the queen triggerfish, Balistes vetula, a versatile predator that both captures and processes prey with its oral jaws. During feeding on three prey that differed in hardness and elusiveness, three distinct patterns of behavior could be identified on the basis of patterns of muscle activity: prey capture, buccal manipulation and blowing. During prey capture by suction feeding, the retractor arcus palatini muscle (RAP) commenced activity before the levator operculi muscle (LOP). In both buccal manipulation and blowing, the RAP began activity well after the onset of activity in the LOP. Both prey capture and buccal manipulation motor patterns varied when fish fed on different prey. When capturing hard-shelled and non-elusive prey, B. vetula did not employ suction feeding but, instead, the fish directly bit parts of its prey. The motor pattern exhibited during direct biting to capture prey was different from that during suction feeding, but was indistinguishable from the pattern seen during the repeated cycles of buccal manipulation. Harder prey elicited significantly longer bursts of activity in the jaw adductor muscles than did soft prey. In spite of the involvement of the oral jaws in virtually all stages of feeding, B. vetula shows levels of variation between patterns of behavior and types of prey characteristic of previously studied teleost fishes. Thus, the coupling of capture and processing behavior patterns in the repertoire of the oral jaws does not appear to constrain the behavioral versatility of this species.


2000 ◽  
Vol 203 (20) ◽  
pp. 3161-3176 ◽  
Author(s):  
J.R. Grubich

This study explores the evolution of molluscivory in the marine teleost family Sciaenidae by comparing the motor activity patterns of the pharyngeal muscles of two closely related taxa, the molluscivorous black drum (Pogonias cromis) and the generalist red drum (Sciaenops ocellatus). Muscle activity patterns were recorded simultaneously from eight pharyngeal muscles. Electromyographic (EMG) activity was recorded during feeding on three prey types that varied in shell hardness. Canonical variate and discriminant function analyses were used to describe the distinctness of drum pharyngeal processing behaviors. Discriminant functions built of EMG timing variables were more accurate than muscle activity intensity at identifying cycles by prey type and species. Both drum species demonstrated the ability to modulate pharyngeal motor patterns in response to prey hardness. The mean motor patterns and the canonical variate space of crushing behavior indicated that black drum employed a novel motor pattern during molluscivory. The mollusc-crushing motor pattern of black drum is different from other neoteleost pharyngeal behaviors in lacking upper jaw retraction by the retractor dorsalis muscle. This functional modification suggests that crushing hard-shelled marine bivalves requires a ‘vice-like’ compression bite in contrast to the shearing forces that are applied to weaker-shelled fiddler crabs by red drum and to freshwater snails by redear sunfish.


2015 ◽  
Vol 114 (5) ◽  
pp. 2564-2577 ◽  
Author(s):  
Stefan R. Pulver ◽  
Timothy G. Bayley ◽  
Adam L. Taylor ◽  
Jimena Berni ◽  
Michael Bate ◽  
...  

We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca2+ indicators. The Ca2+ signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca2+ signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca2+ signals were normally initiated did not eliminate production of Ca2+ waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques.


1978 ◽  
Vol 21 (3) ◽  
pp. 538-562 ◽  
Author(s):  
Frances J. Freeman ◽  
Tatsujiro Ushijima

Laryngeal muscle activity during fluent and stuttered utterances was investigated via electromyography. Analysis revealed that stuttering was accompanied by high levels of laryngeal muscle activity and disruption of normal reciprocity between abductor and adductor muscle groups. Results are interpreted as demonstrating the existence of a laryngeal component in stuttering and showing a strong correlation between abnormal laryngeal muscle activity and moments of stuttering.


2002 ◽  
Vol 16 (2) ◽  
pp. 92-96
Author(s):  
Tiina Ritvanen ◽  
Reijo Koskelo ◽  
Osmo H„nninen

Abstract This study follows muscle activity in three different learning sessions (computer, language laboratory, and normal classroom) while students were studying foreign languages. Myoelectric activity was measured in 21 high school students (10 girls, 11 boys, age range 17-20 years) by surface electromyography (sEMG) from the upper trapezius and frontalis muscles during three 45-min sessions. Root mean square (RMS) average from both investigated muscles was calculated. The EMG activity was highest in both muscle groups in the computer-aided session and lowest in the language laboratory. The girls had higher EMG activity in both investigated muscle groups in all three learning situations. The measured blood pressure was highest at the beginning of the sessions, decreased within 10 min, but increased again toward the end of the sessions. Our results indicate that the use of a computer as a teaching-aid evokes more constant muscle activity than the traditional learning situations. Since muscle tension can have adverse health consequences, more research is needed to determine optimal classroom conditions, especially when technical aids are used in teaching.


2019 ◽  
Vol 2 (1) ◽  
pp. 30-34
Author(s):  
Sanchez Jorielle C ◽  
Manlutac Crisalyn T ◽  
Salas Joven V ◽  
Soriano Marilou R ◽  
Santos Michael E ◽  
...  

The purpose of the study was to describe the dance movements of the folk dance Tinikling which is the most popular traditional dance and former national dance of the Philippines.  The researchers adopted the movement analysis method similar to that of Mackenzie that involves the (1) description of the actual movements which occur at the joints involved; (2) the plane in which the movement occurs; and (3) the muscles producing the movement (agonist & antagonist). In addition, the researchers also had done a mechanical analysis on the lever type involved in the execution of the dance movement in terms of force, axis, and resistance. The prominent dance steps in the Philippine local dance Tinikling are the (1) running, (2) tinikling steps, (3) diagonal step, and (4) straddle jump with a turn step. The joints involved are: hip muscle which is ball and socket type of joint; and knee and ankle which are hinge joints. The major muscles involved in the dance include mostly the lower body muscle groups such as the quadriceps, hamstring, gluts, adductor muscle group, and calves. The type of lever used in performing the dance comprise majority of 1st, 2nd and 3rd class levers. Thus, the Tinikling is a viable dance which could improve the health related fitness of the performers in terms of muscular strength, muscular endurance, cardiovascular endurance and flexibility. Also, the dance could improve skill-related fitness such as power, agility, balance and coordination.


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