The scaling of postcranial muscles in cats (Felidae) II: hindlimb and lumbosacral muscles

Article, 0038 English OPEN
Cuff, Andrew R. ; Sparkes, Emily L. ; Randau, Marcela ; Pierce, Stephanie E. ; Kitchener, Andrew C. ; Goswami, Anjali ; Hutchinson, John R. (2016)
  • Publisher: John Wiley and Sons Inc.
  • Related identifiers: doi: 10.1111/joa.12474
  • Subject: Original Articles | anatomy, biomechanics, effective mechanical advantage, locomotion, mammal, morphometrics

In quadrupeds the musculature of the hindlimbs is expected to be responsible for generating most of the propulsive locomotory forces, as well as contributing to body support by generating vertical forces. In supporting the body, postural changes from crouched to upright limbs are often associated with an increase of body mass in terrestrial tetrapods. However, felids do not change their crouched limb posture despite undergoing a 300-fold size increase between the smallest and largest extant species. Here, we test how changes in the muscle architecture (masses and lengths of components of the muscle-tendon units) of the hindlimbs and lumbosacral region are related to body mass, to assess whether there are muscular compensations for the maintenance of a crouched limb posture at larger body sizes. We use regression and principal component analyses to detect allometries in muscle architecture, with and without phylogenetic correction. Of the muscle lengths that scale allometrically, all scale with negative allometry (i.e. relative shortening with increasing body mass), whereas all tendon lengths scale isometrically. Only two muscles' belly masses and two tendons' masses scale with positive allometry (i.e. relatively more massive with increasing body mass). Of the muscles that scale allometrically for physiological cross-sectional area, all scale positively (i.e. relatively greater area with increasing body mass). These muscles are mostly linked to control of hip and thigh movements. When the architecture data are phylogenetically corrected, there are few significant results, and only the strongest signals remain. None of the vertebral muscles scaled significantly differently from isometry. Principal component analysis and manovas showed that neither body size nor locomotor mode separate the felid species in morphospace. Our results support the inference that, despite some positively allometric trends in muscle areas related to thigh movement, larger cats have relatively weaker hindlimb and lumbosacral muscles in general. This decrease in power may be reflected in relative decreases in running speeds and is consistent with prevailing evidence that behavioural changes may be the primary mode of compensation for a consistently crouched limb posture in larger cats.
  • References (9)

    Adams DC, Otarola-Castillo E (2013) geomorph: an R package for the collection and analysis of geometric morphometric shape data. Methods Ecol Evol 4, 393-399.

    Alexander R (1977) Allometry of the limbs of antelopes (Bovidae). J Zool Lond 183, 125-146.

    Alexander R (1984) Elastic energy stores in running vertebrates. Am Zool 24, 85-94.

    Alexander R, Jayes AS (1978) Vertical movements in walking and running. J Zool Lond 185, 27-40.

    Alexander R, Jayes AS (1983) A dynamic similarity hypothesis for the gaits of quadrupedal mammals. J Zool 201, 135-152.

    Alexander R, Maloiy GMO (1989) Locomotion of African mammals. Sym Zool S 61, 163-180.

    Alexander R, Jayes AS, Maloiy GMO, et al. (1981) Allometry of the leg muscles of mammals. J Zool Lond 194, 539-552.

    Anyonge W (1993) Body mass in large extant and extinct carnivore. J Zoo 231, 339-384.

    1.06 1.15 2.31 2.54 0.029 −4.610 0.841 0.014 0.836 2.76 0.042 −5.129 0.999 0.024 1.57 1.71 1.72 0.862 0.977 1.05 1.1 1.17 1.14 1.32 Table 6. Significant RMA (before and after phylogenetic correction) scaling results for log tendon mass plotted against log body mass, displaying only those that differ from an isometric slope value of 1.00. Results with significant r2 are shown in bold. Column headings as in Table 2.

  • Related Research Results (1)
  • Similar Research Results (1)
  • Metrics
    No metrics available
Share - Bookmark