The extensive range of movement of the avian glenohumeral joint makes functional interpretation of any muscle that crosses the joint difficult. Multiple functional roles for the M. coracobrachialis posterior (CBP), an architecturally complex muscle that lies deep to the M. pectoralis, have been assigned on the basis of its anatomical position. The mechanical properties, neuromotor pattern during flight and the biochemical properties of the CBP in pigeons (Columba livia) were studied by in situ length/active tension and length/passive tension measurements, in vivo electromyography and muscle histochemistry. The action of the muscle was studied directly through in situ stimulation and measurement of humeral excursion in non-reduced preparations.
REFERENCES
Biewener
A. A.
(1998
). Muscle function in vivo: a comparison of muscles used for elastic energy savings versus muscles used to generate mechanical power
. Am. Zool
38
, 703
–.Burkholder
T. J.
, Leiber
R. L.
(1998
). Sarcomere number adaptation after retinaculum transection in adult mice
. J. Exp. Biol
201
, 309
–.Chiappe
L. M.
(1995
). The first 85 million years of avian evolution
. Nature
378
, 349
–.Dial
K. P.
, Goslow
G. E.
Jr., Jenkins
F. A.
Jr. (1991
). The functional anatomy of the shoulder in the European starling (Sturnus vulgaris)
. J. Morph
207
, 327
–.Dial
K. P.
, Kaplan
S. R.
, Goslow
G. E.
Jr., Jenkins
F. A.
Jr. (1988
). A functional analysis of the primary upstroke and downstroke muscles in the domestic pigeon (Columba livia) during flight
. J. Exp. Biol
134
, 1
–.Ettema
G. J. C.
, Huijing
P. A.
(1994
). Effects of destribution of fiber length on active length—force characteristics of rat gastrocnemius medialis
. Anat. Rec
239
, 414
–.Full
R. J.
, Autumn
K.
, Chung
J. I.
, Ahn
A.
(1999
). Rapid negotiation of rough terrain by the death-head cockroach
. Am. Zool
39
, 81
–.Hill
A. V.
(1950
). The dimensions of animals and their muscular dynamics
. Sci. Prog
150
, 209
–.Jenkins
F. A.
Jr. (1993
). The evolution of the avian shoulder joint
. Am. J. Sci
293
, 253
–.Kaplan
S. R.
, Goslow
G. E.
Jr. (1989
). Neuromuscular organization of the pectoralis (pars thoracicus) of the pigeon (Columba livia): Implications for motor control
. Anat. Rec
224
, 426
–.Keurs
H. E. D. J. T.
, Iwasumi
T.
, Pollack
G. H.
(1978
). The sarcomere length—tension relation in skeletal muscle
. J. Gen. Physiol
72
, 565
–.Kubow
T. M.
, Full
R. J.
(1999
). Effects of changing morphology on running stability shown by linearization of a two dimensional hexapod model
. Am. Zool
38
, 81
–.Poore
S. O.
, Ashcroft
A.
, Sanchez-Haiman
A.
, Goslow
G. E.
Jr. (1997
). The contractile properties of the M. supracoracoideus in the pigeon and starling: a case for long-axis rotation of the humerus
. J. Exp. Biol
200
, 2987
–.Roberts
T. J.
, Marsh
R. L.
, Weyand
P. G.
, Taylor
C. R.
(1997
). Muscular force in running turkeys: the economy of minimizing work
. Science
275
, 1113
–.Rosser
B. W. C.
, George
J. C.
(1986
). The avian pectoralis: histochemical characterization and distribution of muscle fiber types
. Can. J. Zool
64
, 1174
–.Sanz
J. L.
, Bonaparte
J. F.
, Lacasa
A.
(1988
). Unusual Early Cretaceous birds from Spain
. Nature
331
, 433
–.Sanz
J. L.
, Chiappe
L. M.
, Perez-Moreno
B. P.
, Buscalioni
A. D.
, Moratella
J. J.
, Ortega
F.
, Poyato-Ariza
F. J.
(1996
). An Early Cretaceous bird from Spain and its implications for the evolution of avian flight
. Nature
382
, 442
–.Sokoloff
A. J.
, Ryan
J. M.
, Valerie
D. S.
, Wilson
D. S.
, Goslow
G. E.
Jr. (1998
). Neuromuscular organization of avian flight muscle: morphology and contractile properties of motor units in the pectoralis (pars thoracicus) of pigeon (Columba livia)
. J. Morph
236
, 179
–.Sonnenblick
E. H.
(1962
). Force—velocity relations in mammalian heart muscle
. Am. J. Physiol
202
, 931
–.Spiro
D.
, Sonnenblick
E. H.
(1964
). Comparison of the ultrastructural basis of the contractile process in heart and skeletal muscle
. Circulation Res
15
, 2
–.Sy
M.
(1936
). Funktionell-anatomische Untersuchungen am Vogelflugel
. J. Orn
84
, 199
–.Walker
C. A.
(1981
). New subclass of birds from the Cretaceous of South America
. Nature
292
, 51
–.Wang
K.
, McCarter
R.
, Wright
J.
, Beverly
J.
, Ramirez-Mitchell
R.
(1991
). Regulation of skeletal muscle stiffness and elasticity by titin isoforms: A test of the segmental extension model of resting tension
. Proc. Natl. Acad. Sci. USA
88
, 7101
–.Wang
K.
, McCarter
R.
, Wright
J.
, Beverly
J.
, Ramirez-Mitchell
R.
(1993
). Viscoelasticity of the sarcomere matrix of skeletal muscles
. Biophys. J
64
, 1161
–.
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