title: Kinematic and behavioral evidence for a distinction between trotting and ambling gaits in the cockroach Blaberus discoidalis.
abstract: Earlier observations had suggested that cockroaches might show multiple patterns of leg coordination, or gaits, but these were not followed by detailed behavioral or kinematic measurements that would allow a definite conclusion. We measured the walking speeds of cockroaches exploring a large arena and found that the body movements tended to cluster at one of two preferred speeds, either very slow (<10 cm s(-1)) or fairly fast (∼30 cm s(-1)). To highlight the neural control of walking leg movements, we experimentally reduced the mechanical coupling among the various legs by tethering the animals and allowing them to walk in place on a lightly oiled glass plate. Under these conditions, the rate of stepping was bimodal, clustering at fast and slow speeds. We next used high-speed videos to extract three-dimensional limb and joint kinematics for each segment of all six legs. The angular excursions and three-dimensional motions of the leg joints over the course of a stride were variable, but had different distributions in each gait. The change in gait occurs at a Froude number of ∼0.4, a speed scale at which a wide variety of animals show a transition between walking and trotting. We conclude that cockroaches do have multiple gaits, with corresponding implications for the collection and interpretation of data on the neural control of locomotion.
authors: Department of Biology, Case Western Reserve University, Cleveland, OH 44106-7080, USA. johnabender@gmail.com
authors: John A
authors: JA
authors: Bender
authors: Elaine M
authors: EM
authors: Simpson
authors: Brian R
authors: BR
authors: Tietz
authors: Kathryn A
authors: KA
authors: Daltorio
authors: Roger D
authors: RD
authors: Quinn
authors: Roy E
authors: RE
authors: Ritzmann
references: J Cell Comp Physiol. 1960 Feb;55:99-110
references: 14437836
references: J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2004 Mar;190(3):217-31
references: 14727135
references: Arthropod Struct Dev. 2004 Jul;33(3):287-300
references: 18089040
references: Integr Comp Biol. 2002 Feb;42(1):149-57
references: 21708704
references: Philos Trans A Math Phys Eng Sci. 2007 Jan 15;365(1850):221-50
references: 17148058
references: J Exp Biol. 1990 Jan;148:129-46
references: 2307925
references: J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2010 Jun;196(6):407-20
references: 20396892
references: J Insect Physiol. 2011 Jan;57(1):12-20
references: 20969872
references: J Exp Biol. 2006 May;209(Pt 9):1617-29
references: 16621943
references: J Exp Biol. 1991 Mar;156:215-31
references: 2051129
references: J Comp Physiol A. 1988 Jul;163(3):317-28
references: 3184004
references: J Exp Zool A Comp Exp Biol. 2006 Nov 1;305(11):923-34
references: 17029269
references: PLoS One. 2010 Oct 26;5(10):e13617
references: 21049024
references: J Neurosci. 2009 Mar 4;29(9):2972-83
references: 19261892
references: J Exp Biol. 2010 Jul 1;213(Pt 13):2294-302
references: 20543128
references: Curr Biol. 2010 May 25;20(10):921-6
references: 20451382
references: Nat Methods. 2009 Jun;6(6):451-7
references: 19412169
references: J Exp Biol. 1999 Mar;202(Pt 5):631-43
references: 9929464
references: J Comp Physiol A. 1992 Sep;171(2):183-94
references: 1432854
references: Source Code Biol Med. 2009 Jul 22;4:5
references: 19624853
references: J Exp Biol. 1997 Jul;200(Pt 13):1919-29
references: 9232006
references: Biol Cybern. 2002 May;86(5):343-53
references: 11984649
references: J Exp Biol. 2008 Feb;211(Pt 3):433-46
references: 18203999
references: Brain Res. 1991 Nov 1;563(1-2):175-83
references: 1786531
references: J Comp Physiol A. 1998 Jan;182(1):11-22
references: 9447710
references: J Exp Biol. 1995;198(Pt 2):435-56
references: 9318078
references: J Exp Biol. 1999 Jun;202 (Pt 12):1603-23
references: 10333507
references: Physiol Rev. 1989 Oct;69(4):1199-227
references: 2678167
references: Zoology (Jena). 2007;110(4):271-89
references: 17482802
references: J Comp Physiol A. 1998 Jan;182(1):23-33
references: 9447711
references: J Exp Biol. 2010 Jun 1;213(11):1907-20
references: 20472778
references: J Exp Biol. 1994 Dec;197:251-69
references: 7852905
references: Biol Cybern. 2000 Nov;83(5):435-42
references: 11073207
references: J Neurophysiol. 2007 Sep;98(3):1685-96
references: 17596420
references: J Exp Biol. 2002 Sep;205(Pt 18):2803-23
references: 12177146