spina

(redirected from Spinae)
Also found in: Dictionary, Medical.

spina

A barrier dividing an ancient Roman circus lengthwise, about which the racers turned.
References in periodicals archive ?
The transition from a lordotic lumbar posture to a fully flexed lumbar spine alters the geometry of the upper erector spinae and lumbar erector spinae, potentially reducing their ability to generate extensor torque and resist anterior shear (Figure 2).
Although increased lumbar flexion alters the geometry of the erector spinae in a way that can potentially compromise its ability to generate an extension moment and resist anterior shear, authors who have investigated back extensor torque in static lumbar postures have found increases in torque as the spine becomes more flexed.
This ability to produce considerably greater torque in a flexed lumbar posture has been attributed to increase in the length of the erector spinae (Raschke and Chaffin 1996).
The length-tension relationship of the erector spinae seems to be supported by studies that have investigated the effect of lumbar posture on the ratio of extensor torque production to levels of erector spinae muscle activation (neuromuscular efficiency ratio) (Roy et al 2003, Tan et al 1993).
The influence of lumbar posture on erector spinae muscle activation and lumbar spine kinematics during dynamic lifting and lowering
An important aspect of transitioning clients into manual handling activities is understanding the relationships between levels of erector spinae muscle activation and lumbar kinematics.
Figure 3A shows an example of a person initiating a lift with a lordotic posture (40% of maximal flexion) and the rate of change in lumbosacral angle (angular velocity) and the extent of erector spinae muscle activation.
When using a flexed lifting posture the upper erector spinae and lumbar erector spinae display quite different activation patterns.
Whilst a number of studies have focused on lumbar posture during lifting, few have investigated the effects that lumbar posture has on bending moments and erector spinae muscle activation during lowering.
Despite showing a similar peak moment, when compared to lifting, muscle activation of the lumbar erector spinae is substantially less when lowering (de Looze et al 1993, Toussaint et al 1995).