Gross structure and function of the quadriceps femoris in Lemur fulvus: An analysis based on telemetered Electromyography†
TL;DR: Analysis based on telemetered electromyography from the quadriceps femoris of Lemur fulvus, a Malagasy prosimian, during walking, galloping, leaping, and a variety of postural behaviors partially confirms and partially contradicts earlier hypothesized functions of this musculoskeletal complex.
Abstract: Analysis based on telemetered electromyography from the quadriceps femoris of Lemur fulvus, a Malagasy prosimian, during walking, galloping, leaping, and a variety of postural behaviors partially confirms and partially contradicts earlier hypothesized functions of this musculoskeletal complex. As predicted on the basis of morphological criteria (large physiological cross-section and long parallel fibers), the vastus lateralis is of special functional significance in leaping. This relatively large muscle consistently initiates the leap and frequently undergoes a very long period of force enhancement via active stretch. By contrast, the vastus intermedius fails to exhibit increased electrical activity and undergoes little or no active stretch during jumps. The myological details of vastus intermedius (short fibers, no fusion with other components), therefore, cannot be accounted for as adaptations to leaping. Rather, a primary postural role is indicated for the vastus intermedius, because in normal resting postures, with the knee quite flexed, it alone is continuously active. The existence of a fibrocartilaginous superior patella in the tendon of vastus intermedius, however, is most plausibly related to the complex tensile and compressive stresses generated in the tendon during the completely hyperflexed phase of leaping. The phasic patterning of the quadriceps femoris of Lemur fulvus does not point to any special role of the vastus lateralis or vastus intermedius during walking and galloping; it does indicate very different patterns of muscle recruitment in comparison to those in nonprimate mammals and some anthropoid primates. The forward cross walk (diagonal sequence, diagonal couplets) of primates versus the backward cross gait (lateral sequence) of most other mammals probably accounts for some of these differences. Lemur fulvus lacks the degree of elastic storage and release of kinetic energy in the quadriceps femoris that characterizes the gallop of dogs, cats, and Erythrocebus patas.
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TL;DR: The current chapter reviews symmetrical gait utilization in primates and compares primates and nonprimates in the activity of certain muscles, especially forelimb muscles, during quadrupedal locomotion, demonstrating that these three topics are not unrelated.
Abstract: In a recent review on locomotor behavior and control in primates, Vilensky (86) suggested that locomotor control mechanisms differ between primates and other cursorial mammals. The current chapter to some extent argues that hypothesis further. Additionally, it reviews symmetrical gait utilization in primates and compares primates and nonprimates in the activity of certain muscles, especially forelimb muscles, during quadrupedal locomotion. Here we will demonstrate that these three topics are not unrelated.
162 citations
01 Jan 1998
TL;DR: One of the most distinctive characteristics of primate quadrupedalism is that they typically utilize a diagonal sequence/diagonal couplets Walking gait pattern, in contrast to the almost universally employed lateral sequence walking gait of nonprimate mammals.
Abstract: Quadrupedal walking and running are certainly not the first things that come to mind when one considers unique aspects of primate locomotion. However, there is a growing body of information about how the form of quadrupedalism displayed by primates differs from that of nonprimate mammals (see Vilensky, 1987, 1989). One of the most distinctive characteristics of primate quadrupedalism is that they typically utilize a diagonal sequence/diagonal couplets walking gait pattern (i.e., foot falls in sequence: left hind, right fore, right hind, left fore, with diagonal limbs moving as a pair), in contrast to the almost universally employed lateral sequence walking gait (left hind, left fore, right hind, right fore) of nonprimate mammals (Howell, 1944; Prost, 1965, 1969; Hildebrand, 1967; Rollinson and Martin, 1981; Vilensky, 1989; Vilensky and Larson, 1989). This difference in gait pattern is not trivial, since a diagonal sequence/diagonal couplet walking gait creates a strong potential for interference between the ipsilateral hind and forelimbs (Figure 1). The potential for hind/forelimb interference is exacerbated in primates by their long limbs (due to their relatively longer limb bones, Alexander et al., 1979), and by their propensity to use relatively longer stride lengths than nonprimate quadrupeds (Vilensky, 1980; Alexander and Maloiy, 1984; Reynolds, 1987). As a result, many primate quadrupeds must regularly “overstride” during walking, that is, touch down with their hind foot ahead of their ipsilateral hand by passing it either “inside” or “outside” of the forelimb (Hildebrand, 1967; Reynolds, 1985b; Larson and Stern, 1987; see Figure 1). Another distinctive aspect of primate gait utilization is the infrequent use of a running trot (defined as diagonal limbs moving synchronously with relative stance duration of each limb less than 50%; see Hildebrand, 1967).
154 citations
TL;DR: The state of the field of GM is assessed and an overview of the techniques available to assess shape, including aspects of visualization, statistical analysis, phylogenetic control, and more are provided.
Abstract: Geometric morphometrics (GM) has increasingly become an important tool in assessing and studying shape variation in a wide variety of taxa. While the GM toolkit has unparalleled power to quantify shape, its use in studies of functional morphology have been questioned. Here, we assess the state of the field of GM and provide an overview of the techniques available to assess shape, including aspects of visualization, statistical analysis, phylogenetic control, and more. Additionally, we briefly review the history of functional morphology and summarize the main tools available to the functional morphologist. We explore the intersection of geometric morphometrics and functional morphology and we suggest ways that we may be able to move forward in profitably combining these two research areas. Finally, this paper provides a brief introduction to the papers in this special issue and highlights the ways in which the contributing authors have approached the intersection of GM and functional morphology. Anat Rec, 298:5–28, 2015. V C 2014 Wiley Periodicals, Inc.
102 citations
Cites background from "Gross structure and function of the..."
...…been combined with kinematic analysis have also elucidated how primates grasp (e.g., Boyer et al., 2007; Kingston et al., 2010), jump and leap (e.g. Jungers et al., 1980; Anapol and Jungers, 1987), knuckle walk (e.g., Tuttle et al., 1972; Tuttle and Basmajian, 1974a,b), and brachiate (e.g.,…...
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TL;DR: Fiber architecture of the extensor musculature of the knee and ankle is examined in two African gueon species and interspecific differences in the triceps surae indicate the inherent flexibility of muscles may be preadaptive to a primary species shift in locomotor modality until the bony morphology is able to adapt through natural selection.
Abstract: Fiber architecture of the extensor musculature of the knee and ankle is examined in two African gueon species--the semiterrestrial Cercopithecus aethiops, and the arboreal C. ascanius. Using histologic and microscopic techniques to measure lengths of sarcomeres, the original lengths of muscle fasciculi and angles of pinnation in quadriceps femoris and triceps surae are reconstructed from direct measurements on cadavers. Calculations of reduced physiological cross-sectional area, mass/predicted effective tetanic tension, maximum excursion, and tendon length/fasciculus+tendon lengths are correlated to preferred locomotor modalities in the wild. For both species, greater morphological differences occur among the bellies of quadriceps femoris--rectus femoris, vastus intermedius, v. lateralis, and v. medialis--than among the bellies of triceps surae--gastrocnemius lateralis, g. medialis, plantaris, and soleus. With regard to quadriceps femoris, few differences occur between species. Interspecific differences in the triceps surae indicate (1) redirection of muscle force to accommodate arboreality in which the substrate is less than body width; (2) muscles more suited for velocity in the semiterrestrial vervets; and (3) muscles used more isotonically in vervets and more isometrically in red-tailed monkeys. The inherent flexibility of muscles may be preadaptive to a primary species shift in locomotor modality until the bony morphology is able to adapt through natural selection.
99 citations
TL;DR: Although non-human primates unquestionably make a better experimental model than cats or dogs for understanding human locomotor control mechanisms, exactly how much better remains to be determined.
73 citations
References
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TL;DR: It was found that the soleus and vastus intermedius muscles had the highest proportion of slow oxidative fibers in all five species, demonstrating the constancy of muscle fiber profiles dependent upon anatomical position and functional utilization.
Abstract: The fiber type profiles of hindlimb muscles in the Hartley guinea pig, Sprague-Dawley rat, cat, Galago senegalensis (lesser bushbaby) and Nycticebus coucang (slow loris) were estimated histochemica...
1,119 citations
TL;DR: The division of labor between MG and SOL and the absolute force levels required from the MG during the full range of hindlimb movements in posture, locomotion, and jumping appear to be precisely matched to the very different characteristics of the motor-units composing these synergistic muscles.
Abstract: 5. During the step cycle the peaks of both MG and SOL force profiles occur before the end of the yield (E2) phase, as both muscles undergo active lengthening. In contrast, peak MG and SOL forces during vertical jumping coincide with the end of active lengthening and the onset of ankle extensor shortening. 6. The results are consistent with the hypothesis that the inherent stiffness of active muscle during the step cycle is an important factor in the control of force output from hindlimb extensor muscles in locomotion. The division of labor between MG and SOL and the absolute force levels required from the MG during the full range of hindlimb movements in posture, locomotion, and jumping appear to be precisely matched to the very different characteristics of the motor-unit populations composing these synergistic muscles.
699 citations
TL;DR: The second molars of insectivorous species were found to parallel closely those of leaf-eating species, and the smallest Living primate leaf-eater is on order of magnitude larger than the largest living primate insectivore.
Abstract: Measurements were taken on the upper and lower molars of 37 species of primates and one tupaiid to assess the relative importance of shearing, crushing and grinding features. Significant correlations were found between pairs of allometrically standardized dimensions which measure the same molar function (shearing, crushing, or grinding). Correlations between pairs of dimensions which do not measure the same function are not significant. Second molar adaptations for shearing, crushing, and grinding, as well as the length of the second lower molar, and the total surface of the post-canine dentition are negatively allometric with respect to metabolic rate. Species which take different proportions of fruit, leaves, and insects in their diets have different molar structure. Frugivores have small teeth for their adult body size with poorly developed shearing, crushing, and grinding features on their molars. By contrast, leaf-eating species tend to have large teeth for their adult body size with well developed shearing, crushing, and grinding. The second molars of insectivorous species were found to parallel closely those of leaf-eating species. The two groups are clearly distinguishable from the former on the basis of body size alone: the smallest living primate leaf-eater is on order of magnitude larger than the largest living primate insectivore.
690 citations
TL;DR: A mechanical model is given for the walking and running processes and appears to be identified as elastic recoil energy from the stretched contracted muscle and amounts to about half the energy spent in running.
Abstract: The external and internal mechanical work in running has been measured through various procedures. Different from walking, in running the work due to the forward speed changes (variation of kinetic energy) and to the vertical displacement of the center of gravity (variation of potential energy), throughout the step cycle, are substantially in phase. The external work performed per kilometer is independent of speed, amounting to 0.25 kcal/kg km. The total mechanical work amounts to about 0.40–0.50 kcal/kg km. The efficiency in running has been calculated as about 40–50%: such a high value involves a contribution of a substantial amount of energy delivered at a very low cost; this appears to be identified as elastic recoil energy from the stretched contracted muscle and amounts to about half the energy spent in running. A mechanical model is given for the walking and running processes. mechanics of locomotion; kinetic and potential energy during step cycle; elasticity of contracted muscle; mechanical models...
610 citations
TL;DR: A cinematographic analysis of the unrestrained walking, trotting, galloping, jumping and landing movements of 11 adult cats was undertaken to provide previously unavailable information concerning the demands imposed on the nervous system for the control of low and high speed movements.
Abstract: A cinematographic analysis of the unrestrained walking, trotting, galloping, jumping and landing movements of 11 adult cats was undertaken to provide previously unavailable information concerning the demands imposed on the nervous system for the control of low and high speed movements and the demands imposed by such natural movements on muscle performance and proprioceptive response.
With due regard for the swing (F and E1) and stance (E2 and E3) phases of the step cycle of an individual limb, single frame analysis of the film permitted measurement of instantaneous angles of the lower spine, hip, knee, ankle and metatarsophalangeal joints. Appropriate lever arm measurements were also made on 50 freshly dispatched cats and 25 cadavers such that the Law of Cosines could be used to calculate instantaneous lengths of select hind limb muscles that would apply to the natural movements of adult cats of small (1.5–2.5 Kg), intermediate (2.6–3.5 Kg) and large (3.6–4.5 Kg) size. Muscle displacements were analyzed relative to maximum and minimus in situ lengths and the lengths associated with quiet standing. Use was also made of a previous electromyographic analysis of hind limb muscles during unrestrained locomotion (Engberg and Lundberg, '69).
The sequential relations between the four phases of the step cycle are maintained as forward speed increases from walking ( 16 mph). There are significant differences in the time consumed by each phase, however, with a greater reduction in the E3 phase, little reduction in the E2 and E1 phases and virtually no reduction in the F phase. When each phase is expressed as a relative percentage of the duration of the total step cycle, the greatest reduction is again in E3 with little change in the E2 phase. In contrast F and E1 phases increase in the percent of time they occur in each cycle, with the greatest increase in the F phase. For all speeds, analysis of the phase relations between movements of various sections of the hind limb revealed a remarkable unity of knee and ankle joint movement. The hip joint is largely out of phase with the knee and ankle during E1 and E2, all three joints being in phase in F and E3. The digits are essentially out of phase with the other joints except in the stance phase of the gallop.
Rates and extents of muscle displacement during natural movements are greater than might be anticipated when expressed in absolute mm's and mm/sec but not when considered in relation to maximum and minimum in situ length and the length associated with quiet standing (Ls). During stepping a progressive increase in forward speed results in: (a) a greater usage of muscles at lengths between Ls and maximum in situ length; (b) for knee and ankle extensors, pronounced increase in the lengthening contraction associated with the E2 (yield) phase of step; and, (c) for both flexor and extensor muscles, an increased active phase of lengthening or near isometric contraction immediately prior to periods of active shortening. In contrast to these changes in active muscle status, the change from walking to galloping has little effect on the extent and rate of passive muscle displacements, particularly the F phase stretch of extensors.
For the soleus muscle, calculations were made of the relation between changes in overall muscle length during natural movements and the length of the average muscle fiber and the tendon of insertion. These measurements revealed that the increases in fiber length when passive and decreases in length during active shortening are less than would be anticipated from the extensive liteature on extirpated fibers. In contrast, the increase in fiber length when active is greater than would be expected from the admittedly sparse literature on this subject.
The results of this study are discussed largely in relation to two points of neurophysiological interest: the physiological range of muscle stretch as it pertains to the responsiveness of muscle spindles and tendon organs; and those mechanical aspects of lengthening contractions that give insight into the neural control of stepping. For exciting both spindles and tendon organs passive muscle stretch and shortening contractions are shown to be relatively ineffective and lengthening and isometric contractions particularly effective movements. It is suggested that, just as recent literature has emphasized the co-activation of efferent alpha and gamma motoneurons as a muscle becomes active, so too is there a synchronous activation of afferents, particularly the Ia and group II endings of muscle spindles and Ib endings of tendon organs. Finally the thesis is advanced that, while it has been convenient to separate E2 from E3 in the description of the stance phase of the step cycle, extensor muscles are actually undergoing a single mechanical event: an active stretch-shorten cycle for knee and ankle extensors and an active isometric-shorten cycle for hip extensors. This hypothesis has significant implications for the neural control program that regulates the stepping sequence in that it emphasizes the extent to which appropriate changes must be preprogrammed in the mechanical properties of muscles for the smooth execution of stepping.
603 citations