Flexibility: Ostrich and sauropod necks

["Richard W. Travsky" <rtravsky@uwyo.edu>]

Apologies if this was already posted, I may have missed it. 
Found this fascinating.

http://www.bbc.co.uk/news/science-environment-23679932

A study of modern-day ostriches suggests the ancient animals 
were probably quite stiff in their movement.

Sauropod dinosaurs had a thick mass of muscle in their necks 
and the researchers say this would probably have restricted 
the range over which the beasts could move their heads.
...


http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0072187

 Inter-Vertebral Flexibility of the Ostrich Neck: 
Implications for Estimating Sauropod Neck Flexibility

Matthew J. Cobley, Emily J. Rayfield, Paul M. Barrett

Abstract

The flexibility and posture of the neck in sauropod 
dinosaurs has long been contentious. Improved constraints on 
sauropod neck function will have major implications for what 
we know of their foraging strategies, ecology and overall 
biology. Several hypotheses have been proposed, based 
primarily on osteological data, suggesting different degrees 
of neck flexibility. This study attempts to assess the 
effects of reconstructed soft tissues on sauropod neck 
flexibility through systematic removal of muscle groups and 
measures of flexibility of the neck in a living analogue, 
the ostrich (Struthio camelus). The possible effect of 
cartilage on flexibility is also examined, as this was 
previously overlooked in osteological estimates of sauropod 
neck function. These comparisons show that soft tissues are 
likely to have limited the flexibility of the neck beyond 
the limits suggested by osteology alone. In addition, the 
inferred presence of cartilage, and varying the 
inter-vertebral spacing within the synovial capsule, also 
affect neck flexibility. One hypothesis proposed that 
flexibility is constrained by requiring a minimum overlap 
between successive zygapophyses equivalent to 50% of 
zygapophyseal articular surface length (ONP50). This 
assumption is tested by comparing the maximum flexibility of 
the articulated cervical column in ONP50 and the flexibility 
of the complete neck with all tissues intact. It is found 
that this model does not adequately convey the pattern of 
flexibility in the ostrich neck, suggesting that the ONP50 
model may not be useful in determining neck function if 
considered in isolation from myological and other soft 
tissue data.

PLoS ONE 8(8): e72187. doi:10.1371/journal.pone.0072187