architectural correlates of locomotion in the hindlimb muscles of two guenon species
DESCRIPTION
Architectural Correlates of Locomotion in the Hindlimb Muscles of Two Guenon Species. Introduction. The investigation: can muscle architectural differences be recognized as the correlates of particular locomotor habits?. Muscle Architecture. The Species:. Cercopithecus aethiops C. ascanius. - PowerPoint PPT PresentationTRANSCRIPT
Architectural Correlates of Locomotion in the Hindlimb
Muscles of Two Guenon Species
Architectural Correlates of Locomotion in the Hindlimb
Muscles of Two Guenon Species
IntroductionIntroduction The investigation: can muscle architectural The investigation: can muscle architectural
differences be recognized as the correlates differences be recognized as the correlates of particular locomotor habits?of particular locomotor habits?
Muscle ArchitectureMuscle Architecture
The Species:The Species:
Cercopithecus aethiops C. ascanius
Muscles of the HindlimbMuscles of the Hindlimb
Gluteal groupGluteal group Gluteus superficialisGluteus superficialis Gluteus mediusGluteus medius Gluteus minimusGluteus minimus
HamstringsHamstrings Biceps femorisBiceps femoris Semi-membranosusSemi-membranosus Semi-tendinosusSemi-tendinosus
Morphometrics Morphometrics Length of the fasciculus between Length of the fasciculus between
the proximal myotendinous junction the proximal myotendinous junction and the distal myotendinous and the distal myotendinous junction (lf) junction (lf)
The perpendicular distance from the The perpendicular distance from the tendon of insertion to the proximal tendon of insertion to the proximal attachment of fasciculus (a) attachment of fasciculus (a)
Length of tendon from the proximal Length of tendon from the proximal attachment (tp )attachment (tp )
Length of the tendon of distal Length of the tendon of distal attachment (td)attachment (td)
Sarcomere LengthsSarcomere Lengths
Angles of Pinnation Angles of Pinnation
Variables Calculated to Estimate Output Potential of the MusclesVariables Calculated to Estimate Output Potential of the Muscles
Reduced physiological cross-sectional area Reduced physiological cross-sectional area RPCA (sq cms) = (mass x cos RPCA (sq cms) = (mass x cos / lf (cms) x specific density/ lf (cms) x specific density
Mass/predicted effective maximal tetanic tension Mass/predicted effective maximal tetanic tension m/po, where po m/po, where po 2.3 newtons x RPCA 2.3 newtons x RPCA
Estimated maximum excursion of distal tendon of Estimated maximum excursion of distal tendon of attachmentattachment h = lf (cos h = lf (cos - ( - (cos cos + n + n22 - 1) - 1)
Tendon length/fasciculus length+tendon length Tendon length/fasciculus length+tendon length lt/lf + ltlt/lf + lt
0
5
10
15
20
25
30
Gluteussuperficialis
anterior
Gluteussuperficialis
posterior
Gluteusmedius
Gluteusminimus
BicepsFemoris
Semimem-branosus
Semi-tendinosus
Vervets
Red-tails
Mass/poMass/po
Estimated ExcursionEstimated Excursion
0
5
10
15
20
25
30
Gluteussuperficialis
anterior
Gluteussuperficialis
posterior
Gluteusmedius
Gluteusminimus
BicepsFemoris
Semimem-branosus
Semi-tendinosus
Vervets
Red-tails
Tendon PercentageTendon Percentage
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Gluteussuperficialis
anterior
Gluteussuperficialis
posterior
Gluteusmedius
Gluteusminimus
BicepsFemoris
Semimem-branosus
Semi-tendinosus
Vervets
Red-tails
RpcaRpca
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Gluteussuperficialis
anterior
Gluteussuperficialis
posterior
Gluteusmedius
Gluteusminimus
BicepsFemoris
Semimem-branosus
Semi-tendinosus
Vervets
Red-tails
•Conclusions•Conclusions Between group differences:Between group differences: intermuscular variability intermuscular variability
greater among gluteal muscles than among hamstrings.greater among gluteal muscles than among hamstrings.
Interspecific differences:Interspecific differences: - Higher relative values for RPCA of gluteus medius than - Higher relative values for RPCA of gluteus medius than
g. Minimus in vervets related to demands of ground g. Minimus in vervets related to demands of ground quadrupedalism. quadrupedalism.
- In vervets muscles are designed for higher velocities, - In vervets muscles are designed for higher velocities, but greater force generation in red-tails.but greater force generation in red-tails.
- Vervet muscles designed more for isotonic contraction, - Vervet muscles designed more for isotonic contraction, by contrast to more isometric use in red-tails.by contrast to more isometric use in red-tails.