Planar covariation of limb elevation angles during bipedal locomotion in common quails (Coturnix coturnix)

Abstract

In human bipedal walking, temporal changes in the elevation angle of the thigh, shank and foot segments covary to form a regular loop within a single plane in three-dimensional space. In this study, we quantified the planar covariation of limb elevation angles during bipedal locomotion in common quails to test whether the degree of planarity and the orientation of the covariance plane differ between birds, humans and Japanese macaques as reported in published accounts. Five quails locomoted on a treadmill and were recorded by a lateral X-ray fluoroscopy. The elevation angle of the thigh, shank and foot segments relative to the vertical axis was calculated and compared with published data on human and macaque bipedal locomotion. The results showed that the planar covariation applied to quail bipedal locomotion and planarity was stronger in quails than in humans. The orientation of the covariation plane in quails differed from that in humans, and was more similar to the orientation of the covariation plane in macaques. Although human walking is characterized by vaulting mechanics of the body center of mass, quails and macaques utilize spring-like running mechanics even though the duty factor is >0.5. Therefore, differences in the stance leg mechanics between quails and humans may underlie the difference in the orientation of the covariation plane. The planar covariation of inter-segmental coordination has evolved independently in both avian and human locomotion, despite the different mechanical constraints.

A kinematic synergy for terrestrial locomotion shared by mammals and birds

“…During forward progression, HL and FL segments oscillate back and forth with specific phasing relative to the footfall pattern ( Figure 3A ). We confirmed the validity of the planar covariation previously reported in humans ( Bianchi et al, 1998b ), macaques ( Courtine et al, 2005 ; Ogihara et al, 2012 ), birds (quails, Ogihara et al, 2014 ), and dogs ( Catavitello et al, 2015 ), and extended it to a large set of other animal species. Even though different recording systems were used in these previous studies, the planarity index (PV 3 ~1–3%) and the orientation of the covariation plane ( u 3 vector) for the bird ( Ogihara et al, 2014 ), human ( Bianchi et al, 1998a ) and dog ( Catavitello et al, 2015 ) were similar to those reported in the current study ( Figure 3 ), confirming the reliability of our kinematic recordings and suggesting that each animal adopted its own pattern of the inter-segmental coordination.…”

“…we found that the u 3 vector rotation correlated with L shank /L foot and L thigh /L foot ), the orientation of the covariation plane reflects specific phase relationships in the control of segment motions ( Bianchi et al, 1998b ; Lacquaniti et al, 2002 ; Ivanenko et al, 2008 ). For instance, birds form a group of animals with a compact orientation of the u 3 vector close to the thigh axis ( Figure 4A , see also Ogihara et al, 2014 ) while primates show rather variable u 3 orientation ( Figure 3—figure supplement 1 ). Also, birds show characteristically wide gait loops, while for other animals the loops are much narrower for HL ( Figure 3—figure supplement 2 ).…”

“…One might expect this to be the case, given the potential connection linking the neuromuscular control patterns, the kinematic synergy, and energy saving at the COM. Initial evidence for the application of the planar law beyond the human species comes from the observation of a similar law in bipedal walking of Japanese macaques ( Ogihara et al, 2012 ) and common quails ( Ogihara et al, 2014 ), as well as in quadrupedal walking Rhesus monkeys ( Courtine et al, 2005 ), dogs ( Catavitello et al, 2015 ) and cats ( Shen and Poppele, 1995 ; Lacquaniti et al, 1999 ).…”

Guineafowl with a twist: asymmetric limb control in steady bipedal locomotion

“…Many researchers have found evidence of joint coordination in steady locomotion (e.g. Ogihara et al, 2014), and we identified similar integration of hip and knee LAR during maneuvering (Kambic et al, 2014). However, in this study we did not find a strong correlation between hip and knee LAR patterns -a result that should be investigated further.…”

Minimizing the cost of locomotion with inclined trunk predicts crouched leg kinematics of small birds at realistic levels of elastic recoil

“…Fischer et al, 2002;Stoessel and Fischer, 2012) that are typically unique and not transferrable between species with different leg geometries (Gatesy and Pollard, 2011). This suggests the existence of criteria such as simplification of locomotor control (Ogihara et al, 2014) or economy of locomotion (Alexander, 1991;Günther et al, 2004) that govern the motion of the segments.…”