... model. In the present study, we used mouse extensor digitorum longus (EDL) muscles in ex vivo experiments to investigate in vivo mechanics of the guinea fowl lateral gastrocnemius (LG) muscle during unsteady running on a treadmill with obstacle perturbations. In vivo strain trajectories from strides...

... prevented growing guinea fowl ( Numida meleagris ) from jumping. We compared the jump performance of our treatment group at maturity with that of controls and measured the morphology of the gastrocnemius elastic system. We found that restricted birds jumped with lower jump power and work, yet there were...

... to investigate the locomotor biomechanics of helmeted guinea fowl traversing slippery surfaces at variable running speeds (1.3–3.6 m s –1 ). Falls were circumvented when limb contact angles exceeded 70 deg, though lower angles were tolerated at faster running speeds (>3.0 m s –1 ). These prerequisites...

... as demand changes. In order to determine the extent to which synergist muscles are functionally heterogeneous, and whether this heterogeneity is altered with changes in demand, we examined the in vivo function of the lateral (LG) and medial (MG) gastrocnemius muscles of helmeted guinea fowl ( Numida...

... of guinea fowl running on the level and uphill using both organismal energy expenditure(oxygen consumption) and muscle blood flow measurements. We tested each bird under four conditions: (1) rest, (2) a moderate-speed level run at 1.5 m s –1 , (3) an incline run at 1.5 m s –1 with a 15% gradient and (4...

...David J. Ellerby; Richard L. Marsh SUMMARY We examined the changes in muscle energy use in guinea fowl running at 1.5 m s -1 either unloaded, or carrying trunk loads equal to 23% of body mass, or loads on their distal legs equal to a total of 5% of body mass. We estimated muscle energy use...

...Richard L. Marsh; David J. Ellerby; Havalee T. Henry; Jonas Rubenson SUMMARY We examined the energetic cost of loading the trunk or distal portion of the leg in walking and running guinea fowl ( Numida meleagris ). These different loading regimes were designed to separately influence the energy use...

... physiologically normal levels of bone strain. Two age-matched groups of juvenile guinea fowl Numida meleagris ran on a treadmill set at either 0° (Level group) or 20° (Incline group), for 10 min per day over a 45-day treatment period. Birds running on the 20° inclined treadmill used more-flexed knees than those...

.... In this paper, we perturb the running of guinea fowl with an unexpected drop in substrate height (Δ H ). The drop is camouflaged to remove any visual cue about the upcoming change in terrain that would allow an anticipatory response. To maintain stability upon a sudden drop in substrate height and prevent...

... for ground-dwelling birds such as phasianids. We hypothesized that by making use of elastic energy storage and release, the leg muscles could provide the large power outputs needed for achieving high velocities after takeoff. We investigated the performance of the leg muscles of the guinea fowl Numida...

... phase work sonomicrometry gastrocnemius digital flexor guinea fowl Numida meleagris Animal limb function must meet the varying mechanical demands of locomotion. In addition to generating force to support body weight, muscles must also produce or absorb energy when animals move over...

... animals utilize this strategy, the input impedance of the respiratory system of five anesthetized, supine guinea fowl ( Numida meleagris ) was measured using a forced oscillation technique. The resonant frequency of the respiratory system was 7.12±0.27 Hz ( N =5, mean ± S.E.M.). No statistically...