Transcript instability
Slide 1 Spinal Stability Tara Jo Manal PT, SCS, OCS Slide 2 Clinical Instability Loss of the ability of the spine under physiologic loads to maintain its pattern of displacement so that there is no initial or additional neurological deficit, no major deformity, and no incapacitating pain » White and Panjabi Slide 3 Clinical Instability Anatomic Considerations Biomechanical Factors Clinical Considerations Treatment Considerations Recommended Evaluation system Recommenced management – Recorded cases of patient post-polio with cervical paralysis and no instability if bones and ligaments remain intact Slide 4 Biomechanics of Spinal Cord and Nerve Roots Cord does not slide up and down (v.small) Accordion like- lengthen on one side and shorten on the other (ie sidebending) Greatest stretching occurs between C2 and T1 (<20%) Injury is due to loss of cord elasticity, displacement or space occupying lesions High compliance in the axial plane, less in the horizontal plane Slide 5 Types of Instability Kinematic Component Instability – Motion increased – Instantaneous axes of rotation altered – Coupling characteristics changed – Paradoxical motion present – Trauma – Tumor – Surgery – Degenerative changes – Developmental chages Slide 6 C0-C1 Unstable in childhood Dislocations are generally fatal Instability identified by x-ray – Rotation >8° is pathological – Translation > 1 mm Slide 7 C1-C2 Instability due to dens fracture Vertebral translation or Rotation Bone spur Little contribution of the facet/capsule compared to dens and ligamentous ring Alar ligament test – C1-C2 > 56° is abnormal Slide 8 Jefferson Fracture C1 Ring Distruption, overhang of lateral masses of C2 Slide 9 C2-T1 Failure consists of injury to posterior and anterior elements Unilateral facet – Root symptoms Bilateral facet Burst Fracture – Spinal medullary injury – Horizontal displacement – Spinal cord injury Slide 10 Recognizing Instability History of a flexion injury Widening of interspinous space Subluxation of a facet joint Compression fracture of adjacent vertebrae Loss of normal cervical lordosis Slide 11 Thoracic Instability T1-T10 Overall greater stiffness Spinal cord damage with injury ~10% T11-L1 Spinal cord damage with injury ~4% Slide 12 Lumbar Instability L1-S1 3% Fracture and dislocation have neurological signs Disconnect between displacement and neurological signs >4.5mm or 15% Facet has a crucial role in stability (rot and SB) Slide 13 Stabilization of the Spine Passive system Active system Neural control Slide 14 Muscular Control of the Spine Rotatores and Intertransversarii Function primarily as force transducers Position Sensors Electrically silent with large rotations (involving Abs) Slide 15 Muscular Control of the Spine Extensors – Longissimus, Iliocostalis Thoracic area ~75% slow twitch fibers Lumbar area ~50% mix Lumbar area- in flexion provide a compressive force in the lumbar to limit shear Slide 16 Muscular Control of the Spine Extensors – Multifidi Span only a few joints Produce extensor torque/resistance Only small amounts of rotation or SB Contribute to correction or support Slide 17 Muscular Control of the Spine Abdominal Muscles Rectus – Major trunk flexor – Active with sit-up and curl-ups – Little to no evidence to support upper/lower differentiation Slide 18 Muscular Control of the Spine Abdominal Wall- Ext/Int Oblique Torso Rotation and Lateral flexion Slide 19 Muscular Control of the Spine Abdominal Wall-Transverse abdominis Beltlike support and generation of intraabdominal pressure Delayed onset during ballistic movements in patient’s with LBP Slide 20 Muscular Control of the Spine Psoas Primarily hip flexor Compressive force to spine during contraction Questionable contribution to spine stability • If so, under high hip flexor forces Slide 21 Muscular Control of the Spine Quadratus Lumborum Highly involved with spine stabilization Active in flexion, extension and SB During Lifting, increased oblique activity followed increases in QL Slide 22 Muscular Control of the Spine Deep Rotators- position sensors Extensor Group – Generate large extensor moments – Generate posterior shear – Affect one or two segments Slide 23 Co-activation of the Muscular Spine 90N force (20lbs) creates buckling without muscular forces Co-contraction increases support against buckling Slide 24 Muscular Stability Continuous contraction ~10% MVIC of abdominals No single muscle is critical one Slide 25 Joint Shear Testing Slide 26 Generalized Ligamentous Laxity Elbow Hyperextension >10° Passive Hyperextension of 5th finger >90° Abduction of thumb to forearm Knee Hyperextension >10° Forward flexion hands to floor (knees ext) Tested Billateral: Total score: /9 Slide 27 Neutral Spine Slide 28 Abdominal Bracing Slide 29 Curl-up Beginner Maintain lordosis with hands Attempt to lift head (little to no motion) Raise head and shoulders (no cervical flexion) One leg flexed one extended Slide 30 Curl-up Intermediate Elbows off the table Slide 31 Curl-up Advanced Fingers on forehead Slide 32 Side Bridge Remedial Slide 33 Side Bridge Reverse Lift legs off the bed Slide 34 Side Bridge Knees Flexed Knees flexed Slide 35 Side Bridge Intermediate Legs extended Slide 36 Side Bridge Intermediate Variation Legs extended Rolling of torso on legs Slide 37 Side Bridge Advanced Slide 38 Birddog, Remedial Hands and knees, raise one hand off bed Progress to hand and opposite knee Slide 39 Birddog, Beginner’s Raise one arm or leg at a time Slide 40 Birddog, Intermediate Raise one arm and leg at a time Hold 6-8 seconds Slide 41 Birddog, Advanced Raise one arm or leg at a time Avoid Returning to the bed, sweep and resume Slide 42 Isometric Rotation Isometric Activity