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nani: 28 Sep : 04:31 AM

plz pleasec tell me where to do phd in india

Nikhilphysio: 02 Jun : 03:55 AM

I am working as physiotherapist in Shalby hospital ahmedabad for 4 years. I have passed out from Rajiv gandhi university of health and sciences Bangalore. I want to apply for Newzealand physiotherapy board registration so anyone there from India who got registered as physiotherapist in new zealand please help me.

Arun: 10 May : 12:36 AM

Hi Priyank, welcome. Feel free to go through these forum threads returned by search [link]

Priyank: 09 May : 10:28 PM

Hi..need advice. What are the options in Australia after MPT?

Arun: 04 Mar : 02:01 AM

Happy birthday Boopathi and somasimple


Rotational Instability Of the Midthoracic Spine Assessment and Management

Diane Lee. Published in Manual Therapy 1(5): 234-291
on Wednesday 29 March 2006
by Diane Lee BSR FCAMT author list email the content item print the content item create pdf file of the content item
in article > Manual Therapy

Diane Lee. Published in Manual Therapy 1(5): 234-291,

Recent research has enhanced the understanding of instability of the spine. The principles of this research has been incorporated into the evaluation and treatment of the unstable thorax. Rotational instability of the midthorax is commonly seen following trauma to the chest. Specific mobility and stability tests have been developed to detect this instability. The tests are derived from a biomechanical model of evaluation. Treatment is based on sound stabilization principles and although the segment will remain unstable on passive testing, the patient can be trained to control the biomechanics of the thorax and return to a high level of function.

Recent research has enhanced the understanding of instability
of the spine. The principles of this research has been incorporated into the
evaluation and treatment of the unstable thorax. Rotational instability of
the midthorax is commonly seen following trauma to the chest. Specific mobility
and stability tests have been developed to detect this instability. The tests
are derived from a biomechanical model of evaluation. Treatment is based on
sound stabilization principles and although the segment will remain unstable
on passive testing, the patient can be trained to control the biomechanics
of the thorax and return to a high level of function.

Introduction

In the literature pertaining to back pain, the musculoskeletal components
of the thorax have received little attention. Research is sparse in all areas
including developmental anatomy, normal biomechanics, pathomechanical processes,
evaluation and treatment. And yet, midback pain is not uncommon. A biomechanical
approach to assessment and treatment of the thorax requires an understanding
of its normal behavior. A working model has been proposed (Lee 1993, 1994a,b)
part of which is based on scientific research (Panjabi 1976) and the rest on
clinical observation. This model requires validation through further research
studies.

The understanding of instability of the spine has been enhanced by recent
research (Hides et al 1994, 1995, Hodges & Richardson 1995a,b, Panjabi
1992a,b, Richardson & Jull 1995, Vleeming et al 1995). The principles of
this research have been incorporated into the evaluation and treatment of the
unstable thorax. Rotational instability of the midthorax involves both the
spinal and costal components of the segment. Specific tests have been developed
(Lee 1993, 1994a,b, Lowcock 1990) to detect this instability and the management
is based on sound stabilization principles (Richardson & Jull 1994).

Anatomy

The thorax can be divided into four regions according to anatomical and biomechanical
differences. The midthorax is the topic of this paper and includes the T3 to
T7 vertebrae, the third to seventh ribs and the sternum. Rotational instability
of the thorax is most common in this region. A brief anatomical review is relevant
in order to understand the normal mechanics and pathomechanics of rotation
in the midthorax.

The facets on both the superior and inferior articular processes of the thoracic
vertebra are curved in both the transverse and sagittal planes (Davis 1959).
This orientation permits multidirectional movement and does not restrain, nor
direct, any coupling of motion when the thorax rotates. Neither do they limit
the amount of lateral translation which occurs in conjunction with rotation
(Panjabi 1976). The ventral aspect of the transverse process contains a deep,
concave facet for articulation with the rib of the same number. This curvature
influences the conjunct rotation which occurs when the rib glides in a superoinferior
direction. A superior glide is associated with anterior rotation of the rib,
an inferior glide is associated with posterior rotation.

The posterolateral corners of both the superior and inferior aspects of the
vertebral body contain an ovoid demifacet for articulation with the head of
the rib. Development of the superior costovertebral joint is delayed until
early adolescence (Penning & Wilmink 1987, Warwick et al 1989). In the
skeletally mature, the costovertebral joint is divided into two synovial cavities,
separated by an intra-articular ligament. Several ligaments support the costovertebral
complex including; the radiate, costotransverse or interosseous ligament, lateral
costotransverse ligament and the superior costotransverse ligament. Attenuation
of some of these ligaments occurs when the midthorax is unstable.

The anatomy and age related changes of the intervertebral disc in the thorax
have received recent study. Crawford (1995) investigated a series of 51 cadavers
aged from 19 to 91 and tabulated the incidence and location of degeneration,
Schmorl’s nodes and posterior intervertebral disc prolapse. The midthoracic
region was found to have the highest incidence of degenerated discs and intervertebral
prolapses. Wood et al (1995) found that 73% of ninety asymptomatic individuals
had positive anatomical findings at one or more levels of the thoracic spine
on magnetic resonance imaging. These findings included herniation, bulging,
annular tears, deformation of the spinal cord and Scheuermann end-plate irregularities.
While structural changes are common, their clinical consequences are unknown.
It is hypothesized (Lee 1993, 1994a,b) that some changes must take place in
the intervertebral disc for the thoracic segment to become unstable in rotation.
These changes may occur prior to the onset of symptoms and predispose the patient
to the development of instability.

Biomechanics of rotation

In the cadaver, Panjabi et al (1976) found that rotation around a vertical
axis was coupled with contralateral sideflexion and contralateral horizontal
translation. Clinically, it appears that in the midthorax, midrange rotation
can couple with either contralateral or ipsilateral sideflexion. At the limit
of rotation, however, the direction of sideflexion has consistently been found
to be ipsilateral. In other words, at the limit of axial rotation, rotation
and sideflexion occur to the same side. It may be that the thorax must be intact
and stable both anteriorly and posteriorly for this in vivo coupling of motion
to occur. The anterior elements of the thorax were removed 3 cm lateral to
the costotransverse joints in the study by Panjabi et al (1976).

During right rotation of the trunk, the following biomechanics are proposed
(Lee 1993, 1994a,b). The superior vertebra rotates to the right and translates
to the left . Right rotation of the superior vertebral body 'pulls' the superior
aspect of the head of the left rib forward at the costovertebral joint inducing
anterior rotation of the neck of the left rib (superior glide at the left costotransverse
joint), and 'pushes' the superior aspect of the head of the right rib backward,
inducing posterior rotation of the neck of the right rib (inferior glide at
the right costotransverse joint). The left lateral translation of the superior
vertebral body 'pushes' the left rib posterolaterally along the line of the
neck of the rib and causes a posterolateral translation of the rib at the left
costotransverse joint. Simultaneously, the left lateral translation 'pulls'
the right rib anteromedially along the line of the neck of the rib and causes
an anteromedial translation of the rib at the right costotransverse joint.
An anteromedial/posterolateral slide of the ribs relative to the transverse
processes to which they attach is thought to occur during axial rotation.

When the limit of this horizontal translation is reached, both the costovertebral
and the costotransverse ligaments are tensed. Stability of the ribs both anteriorly
and posteriorly is required for the following motion to occur. Further right
rotation of the superior vertebra occurs as the superior vertebral body tilts
to the right (glides superiorly along the left superior costovertebral joint
and inferiorly along the right superior costovertebral joint). This tilt causes
right sideflexion of the superior vertebra at the limit of right rotation of
the midthoracic segment .

Definition of instability

Instability can be defined as a loss of the functional integrity of a system
which provides stability. In the thorax, there are two systems which contribute
to stability - the osteoarticularligamentous and the myofascial. Snijders & Vleeming
(Snijders et al 1992, Vleeming et al 1990a,b, 1995) refer to these two systems
as form and force closure. Together they provide a self-locking mechanism which
is useful in rehabilitation.

“Form closure refers to a stable situation with closely fitting joint
surfaces, where no extra forces are needed to maintain the state of the system.” (Snijders
et al 1992, Vleeming et al 1995). The degree of inherent form closure of any
joint depends on its anatomy. There are three factors which contribute to form
closure; the shape of the joint surface, the friction coefficient of the articular
cartilage and the integrity of the ligaments which approximate the joint. The
costal components of the midthorax have considerable form closure given the
shape of the costovertebral joints and the structure of the ligaments.

“In the case of force closure, extra forces are needed to keep the object
in place. Here friction must be present.” (Snijders et al 1992). Joints
with predominantly flat surfaces are well suited to transfer large moments
of force but are vulnerable to shear. Factors which increase intraarticular
compression will increase the friction coefficient and the ability of the joint
to resist translation. The relatively flat zygapophyseal joints provide little
resistance to lateral translation and rely on the form closure of the costal
components and the myofascial force closure for stability. The muscles which
contribute to force closure of the midthoracic region include the transversospinalus
and erector spinae groups. These muscles will be addressed in rehabilitation
of the unstable thorax.

Panjabi has proposed a conceptual model which describes the interaction between
the components of the spinal stabilising system (Panjabi 1992a,b). In this
model, he describes the neutral zone which is a small range of displacement
near the joint’s neutral position where minimal resistance is given by
the osteoligamentous structures. The neutral zone can be palpated during specific
tests for stability. The range of the neutral zone may increase with injury,
articular degeneration (loss of form closure) and/or weakness of the stabilising
musculature (loss of force closure). When the thorax is unstable, the neutral
zone is increased.

Rotational instability of the thorax causes an increase in the neutral zone
which is palpated during segmental lateral translation. The unstable segment
has a softer end feel of motion, an increased quantity of translation and a
variable symptom response. If the joint is irritable, the test may provoke
pain. If the instability is long standing and asymptomatic, the tests are often
not provocative.


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