Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
173 Cards in this Set
- Front
- Back
What are the 2 lordotic curves in the spine?
|
cervical and lumbar
|
|
What are the 2 kyphotic curves in the spine?
|
Thoracic and sacral
|
|
What is the function of the lumbar spine?
|
provide mobility between the thorax and pelvis
|
|
What are the distinguishing features of the lumbar vertebrae?
|
large vertebral bodies, sturdy laminae, and absence of costal facets
|
|
What about the vertebral body contributes to the lordotic curve of lumbar spine and sacrovertebral angle?
|
They are deeper anteriorly
|
|
What is the shape of spinous process in lumbar spine?
|
short, sturdy, and hatchet shaped
|
|
How long are the transverse processes from L1-L4, and what is L5 length?
|
L1-L4 about 1 inch long and L5 is much shorter in length
|
|
What is the function of the mamillary process and where is it?
|
provides for multifidus attachment in lumbar spine and is located on the tip of the superior facet
|
|
What is the shape of the superior facet? (concave or convex) and what direction does it face?
|
Facet is concave and faces posteriomedially
|
|
What is the shape of the inferior facet? (concave or convex) and what direction does it face?
|
Facet is convex and face anteriolaterally
|
|
Where is the pars interarticularis? and what is a common site for?
|
It is located between the superior and inferior facets and in L5 it is common for spondylolisthesis. Known as scotty dog
|
|
How much space does the nucleus fill up of the disc in the lumbar region?
|
30-50% and it is relatively posterior
|
|
What direction are annular fibers oriented?
|
obliquely except in the posterior they run vertically making this area vulnerable to herniation
|
|
Flexion causes the nucleus of the disc to move in which direction?
|
posteriorly
|
|
Extension causes the nucleus of the disc to move in which direction?
|
anteriorly
|
|
Function of iliolumbar ligament and where it attaches
|
reinforces the lumbosacral junction by counteracting anterior shear forces of L5/S1. Arises at the tip of L5 TP and gives rise to 2 bands that attach to ilium
|
|
What are the 3 deep layers of the lumbar spine musculature?
|
from superficial to deep: semispinalis, multifidus, and rotatores
|
|
The deep musculature of the spine attach to what and how many segments do they span?
|
Spinous process to transverse process. span 1-2 segments the length of the spine
|
|
What are are the 4 muscles of the lumbar spine?
|
Quadratus lumborum, EO, IO, and TA. TA and IO connect to the throacolumbar fascia
|
|
What is the conus medularis?
|
the furthest extent of the vertebral column the spinal cord extends to and is usually around L2
|
|
Do MRI findings predict who has LBP in acute or chronic situations?
|
no
|
|
Do MRI findings predict success or nonsuccess in rehabilitation or in future disability?
|
no
|
|
When should a clinician preform diagnostic imaging and testing for patients with LBP?
|
When severe or progressive neurologic deficits are present or when serious underlying conditions are suspected on the basis of history and physical examination. when it will change their POC
|
|
What are the red flags we are looking for during patient examination?
|
Cancer, vertebral infection, vertebral compression fracture, severe to progressive neurological deficits
|
|
Do MRI findings predict who has LBP in acute or chronic situations?
|
no
|
|
Do MRI findings predict success or nonsuccess in rehabilitation or in future disability?
|
no
|
|
When should a clinician perform diagnostic imaging and testing for patients with LBP?
|
When severe or progressive neurologic deficits are present or when serious underlying conditions are suspected on the basis of history and physical examination. when it will change their POC
|
|
What are the red flags we are looking for during patient examination?
|
Cancer, vertebral infection, vertebral compression fracture, severe to progressive neurological deficits
|
|
Give an example of a patho-anatomic diagnosis
|
Herniated disc L4-5
Polymyositis |
|
Give an example of a prognostic/treatment based diagnosis
|
manipulated classification
Specific exercise classification Elevated fall risk |
|
What is pre-test probability?
|
For any given patient, there is a baseline probability of a certain condition pre-testing
|
|
What is post-test probability
|
Application of a clinical diagnostic test alters the baseline probability
|
|
What are 2 key components of diagnosis?
|
probability and patterns
|
|
What is the biomedical model?
|
1. pain is a reflex response to a physical stimulus
2. every symptom has an underlying stimulus 3. alleviating the symptoms requires identifying and alleviating the underlying stimulus 4. All disease is explained in terms of derangement of underlying physical mechanisms |
|
What is the problem with the biomedical model?
|
1. the biomedical model has transformed from a model into cultural dogma
2. Not all conditions appear to fit, this is particularly true for LBP and much of musculoskeletal medicine |
|
What are the 4 steps in diagnosing using the medical model?
|
1. signs and symptoms analyzed
2. pathology determined 3. treatment of pathology 4. signs/symptoms disappear |
|
What are the 4 components to the biopsychosocial model?
|
1. pain
2. attitudes and beliefs 3. Psychological disorders 4. Illness behavior We also look at personality, life events, pain history and coping strategy |
|
What is the key patient message after a thorough physical exam?
|
" The good news is that your neurological exam is normal. your imaging findings are frequently seen in people without pain and were likely there prior to this bout of LBP"
|
|
What are the top disorders we don't want to miss?
|
Cancer, Cauda equina syndrom (CES), Abdominal aortic aneurysm, fracture, suicide, or major depression
|
|
What are the red flags for cancer?
|
Prior history of cancer (Sp: 98%, +LR 32.7)
50 or older, unexplained weight loss, or previous history of cancer, or failure to improve over 1 month (Sn 100%, - LR .06) |
|
Red flags for spinal infection
|
local tenderness of SP, spinal percussion painful (+LR=2.1, sp= .6, sn= .86, -LR=.23)
Also have potential fever, chills, fatigue, night pain post surgical More often bacterial infections, but also from viral |
|
Red flags for CES?
|
urinary retention, unilateral or bilateral sciatica, unilateral or bilateral motor/sensory deficits, positive SLR, sensory deficit of buttocks, posterior-superior thigh, perianal regions
|
|
AAA signs and symptoms
|
1. "throbbing" or "pulsating" pain
2. abdominal and back pain 3. no comfortable position 4. pulsating mass in abdomen with or without pain |
|
What are 3 things you should do if you are suspicious of AAA?
|
1. palpate aortic pulse-identify a widening pulse width
2. if trained us auscultation to detect bruits (abnormal blowing or swishing sounds) 3. seek immediate consultation |
|
5 red flags for identifying vertebral fractures.
|
major trauma
pain and tenderness age > 50 Female Distracting painful injury |
|
2 questions to ask to assess depression
|
"over the past 2 weeks, have you felt down, depressed, or hopeless?" or "over the past 2 weeks, have you felt little interest or pleasure in doing things?" one yes answer Sp=57% and Sn=96%
|
|
2 signs of major depression
|
depressed mood most of the day nearly every day
markedly diminished interest or pleasure in all, or almost all, activities |
|
Signs and symptoms of digestive or GI system disorders
|
1. difficulty swallowing, heartburn, and indigestion, specific food intolerances, changes in appetite, bowel disfunction
|
|
key factors of ankylosing spondylitis
|
1. morning stiffness > 30 min duration
2. improvement in LBP with exercises but not with rest 3. night pain during second half of night only 4. alternating buttock pain 2 of 4: SP 84%, + LR of 2.3 3 of 4: SP 97%, + LR 12.4 |
|
With diagnostic triage what are 3 categories we are looking at with the lumbar spine?
|
1. Serious spinal pathology
2. Nerve root pain 3. Simple/mechanical backache |
|
Signs of infection
|
1. Temp> 100
2. BP>160/95 mmHg 3. Resting pulse > 100/min 4. Resting respiration > 25/min |
|
What are other potentially sinister symptoms?
|
1. pain constant, unrelated to position or movement
2. severe night pain 3. unexplained weight loss 4. blunt trauma 5. weakness or malaise 6. Abdominal pain radiating into groin, hematuria 7. sexual dysfunction 8. menstrual irregularities 9. bowel or bladder dysfunction/ saddle anesthesia |
|
Signs of nerve root pain (synonyms: radiculopathy, sciatica)
|
1. unilateral leg pain worse than back pain
2. pain radiates to foot or toes 3. numbness or paresthesia in same dermatomal distribution 4. nerve irritation signs 5. motor, sensory or reflex changes (limited to on nerve root) |
|
Signs of simple backache (synonyms: lumbago)
|
1. Usually 20-55 years old
2. Lumbosacral region, buttocks or thigh 3. Pain is mechanical in nature: varies with physical activity, varies with time 4. Patient is well |
|
Is a lower or higher oswestry score better?
|
lower
|
|
What are the 3 levels of treatment-based classification?
|
Level 1 (medical screening): is the patient appropriate for PT
Level 2 (staging): What is the level of acuity Level 3 (classification): What treatment should be used |
|
During level 1 of the classification program what are the 3 categories a pt could fall into?
|
1. pt appropriate
2. consultation 3. referral |
|
Is level 2 (staging) (what is the level of acuity) based on time of onset?
|
no
|
|
What is staging (level 2) based on?
|
based upon symptoms and functional limitation
|
|
What tools do we use to stage patients
|
1. oswestry disability questionnaire
2. numeric pain rating |
|
What are is the functional limitations for stage 1 patients (acute) and what are the goals of therapy?
|
functional limitations: (unable to)
1. stand >15 min 2. sit> 30 min 3. walk > 1/4 mile 4. Oswestry > 25% Goals of therapy is pain modulation |
|
What are functional abilities of stage 2 (subacute) and what are the goals of physical therapy
|
1. exceeds stage 1 requirements (can sit, stand, walk)
2. Pain prevents ADLs (oswestry< 25%) Goals: pain modulation continues and address impairments (flexibility, aerobic conditioning, spinal stabilization, etc) |
|
What are the functional abilities of stage 3 (enhance performance) and what are the goals of physical therapy
|
difficulty returning to high-demand activity (manual labor, athletics, household duties)
Oswestry <20% Goal: Enable to work (work hardening, return to sport) |
|
What is the purpose of level 3 (initial management approach)?
|
Applying the appropriate initial treatment and put into classification group
|
|
What are the manipulation intervention procedures of the manipulation group?
|
1. manipulation of lumbopelvic region
2. Active ROM exercises |
|
What are the stabilization intervention procedures of the stabilization group?
|
1. promoting isolated contraction and cocontraction of the deep stabilizing muscles (multifidus, TA)
2. Strengthening of large spinal stabilizing muscles (erector spinae, oblique abdominals) |
|
What are the interventions for the specific exercise-extension group
|
1. end-range extension exercises
2. mobilization to promote extension 3. Avoidance of flexion activities |
|
What are the interventions for the specific exercise-flexion group
|
1. mobilization or manipulation of the spine and/or lower extremities
2. exercise to address impairments of strength or flexibility 3. body weight-supported treadmill ambulation |
|
What are the interventions for the specific exercise-lateral shift group
|
1. exercises to correct lateral shift
2. mechanical or autotraction |
|
What are the interventions for the traction group?
|
mechanical or autotraction
|
|
What are the factors that favor a pt for manipulation?
|
1. Duration of symptoms 16 days or less
2. Symptoms not distal to the knee 3. FABQ work subscale 18 or less 4. At least one hip with internal rotation 35 degrees or more (in prone) 5. Hypomobility at one or more lumbar levels with spring test |
|
What are the factors that favor a pt for stabilization?
|
1. younger age
2. Positive PIT 3. Aberrant motions present 4. greater SLR motion 5. Hypermobility with spring testing 6. Increasing episode frequency 7. 3 or more prior episodes |
|
What are the factors that favor a pt for specific exercise?
|
1. strong preference for sitting or walking
2. centralization with motion testing 3. peripheralization in direction opposite centralization |
|
What factors determine whether or not a PT will use spinal manipulation in a patient with LBP?
|
1. Therapist factors
2. Patient factors 3. Regional factors |
|
What are the effects of manipulation that make it so we see clinical benefits?
|
1. Biomechanical effects
2. Neurophysiological effects 3. Hypoalgesic effects |
|
Does pain going down the leg mean true sciatica or nerve root pain?
|
no
|
|
What are some signs of true radiculopathy?
|
strength loss in myotomal pattern
sensation loss in a dermatomal pattern Decrease or absence of associated DTR |
|
Can lumbar spine structures refer pain to LE and what does it feel like if they can?
|
yes. deep, achy, diffuse, dull, cramp-like and poorly localized
|
|
What are 3 good tests for nerve root pain/radiculopathy?
|
1. SLR
2. X-SLR 3. Femoral nerve stretch test |
|
When does a patient fall into the traction category?
|
LE pain does not centralize with extension and they are positive for XSLR
|
|
What are some of the potential causes with a patient who has predominate lower extremity symptoms that don't fit? (no nerve root signs, crossed-SLR or indeterminate movement testing)
|
1. Denervation
2. Central sensitization 3. Peripheral nerve sensitization 4. Musculoskeletal (to include neural connective tissue) |
|
What do we do with a patient who has symptoms referred distal to the buttocks, positive slump, no directional preference, and oswestry disability> 10%
|
do slump stretch coupled with standard PT
|
|
Should patients with sciatica ever be on bed rest?
|
no they should stay active
|
|
When looking at outcome measurements of treatment what are some aspects we look at?
|
1. Clinical outcomes
2. Process outcomes 3. Patient Satisfaction 4. Costs |
|
What is a surrogate endpoint
|
An outcome that is used as a substitute when a "most clinically meaningful endpoint" is unmeasurable
|
|
How do we measure the active pathology of a patient?
|
laboratory&imaging studies, surgical findings
|
|
How do we measure impairments?
|
Findings from clinical examination
|
|
How do we measure functional limitations and disability?
|
Observation and patient self report
|
|
What is an impairment?
|
problems in body function or structure such as a significant deviation or loss
|
|
What is an activity limitation?
|
difficulties an individual may have in the performance of activities
|
|
What is a participation restriction?
|
problems an individual may have in the manner of extent of involvement in life situation
|
|
Environmental factors make up what?
|
physical, social, and attitudinal environment in which people live and conduct their lives
|
|
What are personal factors?
|
personal features which can have an impact on an individual's performance in each component of the ICF model
|
|
What are the types of HRQol questionnaires?
|
1. Generic (SF-36 EQ-5D)
2. Disease-specific (spinal stenosis index) 3. Region-specific (DASH, Oswestry) 4. Domain-specific (pain, depression) |
|
What are some of the considerations when looking at outcome measures?
|
1. Practicality/feasibility
2. Validity 3. Reliability 4. Responsive |
|
What are the deep core stablizers?
|
1. diaphragm
2. TA 3. Pelvic floor 4. Deep fibers of lumbar multifidus |
|
What is key to motor control exercises?
|
relearning of inhibited muscles may be more important than strengthening patients with LBP
|
|
What progression should we follow when doing motor control exercises?
|
1. specific localized stabilization training
2. stabilization training 3. functional stabilization training |
|
What are some of the predictions for success of lumbar stabilization?
|
1. +PIT
2. Aberrant movement present 3. Average SLR >91 4. <40 y.o. |
|
What is aberrant motion?
|
1. painful arc in flexion
2. painful arc in return from flexion 3. Gower's sign 4. instability catch 5. reversal of lumbopelvic rhythm |
|
What is an important exercise for spondylolithesis and spondylolysis
|
multifidus and TA co-activation
|
|
Should we consider progressive lumbar stabilization exercises for H.S. strains
|
yes
|
|
does stabilization help chronic LBP, unilateral LBP indicative of multifidus atrophy, and hypermobility on PE
|
yes
|
|
Should we do motor control exercise or progressive resistance for people with LBP
|
It is not a question of either or but looking at proper sequence/timing of when to do each type based on patient's symptoms
|
|
Based on evidence do we see that there is one better type of exercise for patients with LBP (motor control vs. progressive resistance vs. manual therapy vs. other types of exercise)
|
no difference but may be due to the heterogeneity of the subjects with LBP that participated in study
|
|
Does movement relieve chemical pain?
|
yes but it is not sustainable
|
|
What is the best way to treat chemical pain?
|
treated best with drugs to alter chemical agents
|
|
What is chemical pain?
|
When nocioceptors become activated by damage causing high concentration of irritating chemicals
|
|
What is mechanical pain?
|
When nocioceptors become activated by force, stress, deformity, or damage. It can be reduced or abolished by repeated motion or sustained positioning in the correct direction
|
|
Does disc migration reduce with age?
|
yes
|
|
What is postural syndrome (mckenzie)?
|
1. End range stress on normal tissue
2. Positional pain. no loss of movement 3. No pain during movement e.g. sitting too long and knee becomes painful but is relieved when you move |
|
What is dysfunction syndrome (mckenzie)?
|
1. End range stress on shortened tissue
2. Pain at end range or upon stretching of "contracted" tissues. loss of motion 3. no pain in midrange movements |
|
What is derangement syndrome (mckenzie)?
|
caused by an anatomical disruption and or displacement of structures, a mechanical deformation of soft tissue as a result of an internal derangement
|
|
With derangement is there pain during movement?
|
yes
|
|
What is a lateral shift and how often to patients move away from the pain?
|
When a person shifts their upper segments away from the spine and 9/10 patients deviate away from the symptoms
|
|
If the disc or bulge is lateral to the nerve root which way does the patient shift?
|
away from pain
|
|
If the disc or bulge is medial to the nerve root which way does the patient shift?
|
toward the pain
|
|
Does the mckenzie program allow the patient to self treat?
|
yes
|
|
Should the therapist augment techniques with the mckenzies
|
yes
|
|
What is stenosis?
|
A focal narrowing of the lumbar spinal canal, nerve root canal, and/or intervertebral foramina that produces compression of the neural elements
|
|
What is the most common cause of narrowing or stenosis of the lumbar region?
|
arthritic or degenerative changes
|
|
What are the clinical presentations of stenosis?
|
age over 65 (Sn=.77)
Pain below buttocks (Sn=.88) No pain when seated (Sp=.93) Pain with flexion (Sn= .88) Sitting best (Sn=.89) Standing/walking worst (Sn=.89) |
|
What is nerve claudication?
|
cramping leg pain or weakness originating from the nerve. usually accompanies stenosis and is relieved with flexion
|
|
What type of posture is indicative of stenosis?
|
flexed at thoracic, lumbar, and hips
|
|
What type of gait is indicative of stenosis?
|
wide-based, flexed, assistive device
|
|
Stenotic patients typically have what tight muscles?
|
iliopsoas/RF tightness
|
|
During the physical exam of a stenotic pt what muscle performance/motor control deficits will you see?
|
Glut med/maximus and hip ER weakness, and difficulty activating abdominals, poor motor control
|
|
During the physical exam of a stenotic pt what neurological changes will you see?
|
20-50% of patients, at least 1 spinal level, ankle PF weakness
|
|
What typical deficits will you see at the knee and ankle of a stenosis pt?
|
knee extension and ankle DF
|
|
What does the two stage treadmill test show?
|
pt with stenosis typically have earlier onset and prolonged recovery when walking on level treadmill with longer total walking time on a inclined treadmill
|
|
When a patient is riding a bike in flexion and symptoms get worse what is it likely due to?
|
vascular claudication
|
|
When a patient is riding a bike in flexion and symptoms get better what is it likely due to?
|
neurogenic claudication
|
|
What are 3 good interventions for stenotic patients?
|
1. manual physical therapy
2. Flexion exercise 3. Unloaded treadmill walking program |
|
What is the best way to centralize symptoms in a stenotic pt?
|
1. repeated flexion exercises
2. rotational exercises in side-lying |
|
What is the best way to restore upright posture in stenotic patients?
|
1. increase throacic/lumbar extension
2. Rotational mob/manip, PA, Translatoric mob/manip 3. increase hip extension- mob/manip, stretch hip flexors |
|
What types of exercises should we do with stenotic patients?
|
1. muscle balance: LE strengthening
2. Conditioning: walking, cycling 3. Core Stabilization- Abdominal motor control emphasis |
|
What are potential pain generators in the lumbar spine? (9)
|
1. muscles
2. ligaments 3. dura mater 4. nerve roots 5. zygapophyseal joints 6. sacroiliac joint 7. annulus fibrosus 8. throacolumbar fascia 9. vertebrae |
|
Radicular pain?
|
sharp, shooting, superficial or deep pain into the leg in a defined band
|
|
Radiculopathy?
|
radiating paresthesia, numbness in a dermatome, weakness, or combo of these, but not pain
|
|
what is somatic pain?
|
poorly aching pain
|
|
When is radicular pain elicited?
|
it is only elicited when previously damaged nerve is compressed
|
|
Can a patient have radicular pain or radiculopathy and not both together?
|
yes
|
|
What does the pain neuromatrix suggest?
|
pain is produced in the brain as a reaction to a perception of danger to body tissue that requires action
|
|
What two systems involve pain?
|
sensory and emotional
|
|
Where is pain produced?
|
the brain
|
|
Can pain be trusted as adequate reflection of the state of the tissues?
|
no. pain can be the result of actual or perceived tissue damag
|
|
What are the effects of pain on cortical output?
|
1. reduces cortical processing capacity
2. slows decision making 3. increases cognitive error rate 4. pain sufferers report for forgetfulness and being easily distracted 5. Immune activity is modified 6. hypothalmus-pituitary adrenal axes and sympathetic nervous system activity is altered 7. reproductive system functioned altered |
|
What are the Erector Spinae muscle groups of the back?
|
Iliocostalis
Longissimus Spinalis (Lateral --> Medial: I Like Spaghetti) |
|
What are the deep muscle groups of the back?
|
Semispinalis
Multifidus Rotatores (Superficial --> Deep) |
|
What are appropriate cases for screening with an MRI? (6)
|
Cancer
Hx of cancer Vertebral infection Vertebral compression fracture Ankylosing Spondylitis Severe/progressive neuro defects |
|
What percentage of patients have non-mechanical back pain and what percent have visceral?
|
Non-mechanical: 1%
Visceral: 2% |
|
Is prior Hx of Cancer a very specific or very sensitive tool?
|
Very Specific --- Good for ruling in Cancer
|
|
95% of Lumbar Radiculopathy occurs at what vertebral level?
|
L5/S1
|
|
Is there a pain center in the brain?
|
no
|
|
Long term pain may be a result of what?
|
enhanced brain activity
|
|
What is central sensitization?
|
When we get generalized hyperalgesia that is due from changes on the brain and spinal cord level
|
|
What happens during hypersensitization at the spinal cord level?
|
Light touch nerves a-beta cross over and interact with c-fibers. making even light touch painful
|
|
What are three aspects of managing patients with long term pain?
|
1. reduction of threatening input so as to reduce activity of the pain neuromatrix and thereby reduce its efficacy
2. Targeted activation of specific components of the pain neuromatrix without over activating neuromatrix 3. upgrading physical and functional tolerance by graded exposure to threatening inputs across sensory and non-sensory domains |
|
Can education strategy addressing neurophysiology and neurobiology of pain have a positive effect on pain, disability, catastrophization, and physical performance in patients with chronic MSK pain?
|
yes
|
|
What is has been associated with increasing pain, disability, medication usage, and unemployment in the low back population?
|
depression
|
|
What 3 questions are on the depression screen?
|
1. During the past month have you often been bothered by feeling down, depressed, or hopeless
2. during the past month have you often been bothered by little interest or pleasure in doing things? 3. Is this something with which you would like help? |
|
The depression screening questionnaire is good for ruling out or ruling in?
|
ruling out
|
|
If a patient answers yes to the 2 screening questions for the depression screening questionnaire and the additional help question is it good for ruling out or in?
|
ruling in
|
|
What are 3 ways we as therapist can improve our language to help the patients pain decrease?
|
1. use language to foster success
2. get rid of physical therapy "medical speak" and "jargon" 3. get rid of words that create fear or promote misunderstanding through lack of clarity |
|
What is pain not and what is pain?
|
pain is not necessarily reflective of the state of the tissues rather it is a reflection of the brain's attempts to protect you from actual or perceived danger
|
|
Is pain education a viable intervention strategy to use in the treatment of patients in pain?
|
yes
|
|
Is language really create either success or encourage failure?
|
yes
|
|
How can we help patients who have hypervigilance, catastrophic beliefs about pain, or passive coping strategies?
|
treat with patient pain neurophysiology education and patient education
|
|
How can we help patients who have hypervigilance, catastrophic beliefs about pain, or passive coping strategies?
|
treat with patient pain neurophysiology education and patient education
|
|
is there a clear consistent definition of lumbar instability?
|
no
|
|
What are the goals of a spinal fusion?
|
the goal of spinal fusion is to stabilize a segment of the spine that has weakened and eliminated motion at that segment. this stabilization will ideally reduce the pain that is associated with vertebral movement.
|
|
What LR signifies a robust, specific test?
|
+LR > 10
|
|
What LR signifies a good, sensitive test?
|
-LR < 1
0.1 is better |